cdp final report

Optimization of a TEGdehydration unit withrecent advances in tech-nology CPD (3425)

Team 10

TechnischeUniversiteitDelft

Optimization of a TEG dehydrationunit with recent advances in

technology CPD (3425)

by

Team 10

Javier Leyva Rico - 4415027 - +31617370757

Agnes van Endhoven - 4174933 - +31627117687

Ameya Thakurdesai - 4411153 - +31617327604

Toon Nieboer - 4114965 - +31641317731

Assignment issued: 28-04-2015Report issued: 26-06-2015Appraisal: 30-06-2015

in partial fulfillment of the requirements for the course of

Design Projectin Chemical Engineering

at the Delft University of Technology,

Technical advisor: Dr. P. Hamersma, TU DelftCreativity Coach: Prof. dr. B. Dam, TU DelftPrincipals: Ir. A. Didden, Frames Group

Ir. A. Malhotra, Frames Group

Preface

For the conceptual design project of the master Chemical Engineering we, a group of four students,have been put together to work on an assignment for M/s Frames. The main purpose of the project isto decrease the size and costs of an offshore TEG gas dehydration unit, a widely used technique for gasdehydration. This has been done by adding new technologies from industry. For the past 10 weeks,literature studies were performed, contacts with professors and companies have been made and manysimulations and calculations were done.

After a study, some thorough & some brief, out of nine different technologies three were chosen tobe added to the conventional process in order to try to decrease the CAPEX, OPEX and weight of theunit. Pervoparation membranes, a liquid turbochargers and injection of semi-lean TEG were included.

The conventionally used process has been simulated to set a benchmark and the impact of alldifferent techniques has been calculated. Thereafter the hybrid process was simulated. This resultedin a reduction of OPEX of € 70,000 per year, but also an increase of 15 million €, which means theCAPEX has doubled. The weight of the unit stayed more or less the same as is shown in the report.

In the end it is concluded that the addition of liquid turbochargers has a positive effect on the totalenergy needed for the TEG transport throughout the plant. A reduction of 70% of energy consumptionis achieved. The pervaporation membranes decrease the energy needed for reboiling but turn out tobe very costly in capital expenses. As of now it is not yet beneficial to add these membranes as therate of return is too low. It is expected that after more research the price of these membranes candrop however, as a larger surface area per unit can be achieved. This will cut down the capital costs ofthe membranes and make them a viable option in the future. The addition of semi-lean TEG injectionproved a useful addition. It resulted in a size reduction of the still column, reboiler and surge vessel. Toimplement this technology in the conventional process however the design of the still column needs tobe altered or the distillation needs to be done in two steps in order to provide a semi-lean TEG streamto return to the contactor (absorption tower).

Team 10: Javier Leyva, Ameya Thakurdesai, Agnes van Endhoven & Toon NieboerDelft, June 2015

iii

Contents

1 Introduction and Project Charter 11.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 Concept Stage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3.1 Process synthesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.3.2 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.3.3 Plant capacity and location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.4 Database. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.4.1 Component list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.4.2 Component and thermodynamic properties . . . . . . . . . . . . . . . . . . . 5

2 Conventional Process 72.1 Process description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1.1 Contactor (C101) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.1.2 Flash (V201). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.1.3 Filters (S201) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.1.4 Reboiler (V202) & Still column (C201) . . . . . . . . . . . . . . . . . . . . . . 92.1.5 Stripping column (C202) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.1.6 Surge (V203) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.2 Mass and energy balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.2.1 Simulation on Aspen Hysys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.3 Equipment sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.4 Total weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.5 Health, Safety & Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.5.1 Preliminary study of risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.5.2 Dow’s Fire and Explosion Index (F&EI) . . . . . . . . . . . . . . . . . . . . . . 142.5.3 Waste. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.6 Bottlenecks and possible improvements . . . . . . . . . . . . . . . . . . . . . . . . . 17

3 Innovation Map 193.1 Description of alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.1.1 Improved TEG injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193.1.2 Microwave heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193.1.3 Super-X packing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203.1.4 Liquid turbochargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.1.5 Pervaporation membranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.1.6 Molecular sieves + TEG unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223.1.7 Addition of entrainer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233.1.8 Vacuum operation in still column . . . . . . . . . . . . . . . . . . . . . . . . . 233.1.9 Rotating packed beds (HiGee) . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.2 Selection of alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243.2.1 Turbochargers and split-flow injection . . . . . . . . . . . . . . . . . . . . . . 253.2.2 Alternative 1: Process scheme with microwave heating . . . . . . . . . . . . 283.2.3 Alternative 2: Process scheme with pervaporation membranes and semi

lean injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303.2.4 Alternative 3: Process scheme with hybrid system . . . . . . . . . . . . . . . 38

3.3 Selection of the optimized process scheme. . . . . . . . . . . . . . . . . . . . . . . . 39

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vi Contents

4 Hybrid Process 414.1 Process description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414.2 Material and energy balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4.2.1 Energy demands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434.3 Equipment sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434.4 Total weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474.5 Safety, Health & Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4.5.1 Hazard and Operability study (HAZOP) . . . . . . . . . . . . . . . . . . . . . . 474.6 Process control and instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

5 Economic Analysis 515.1 CAPEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

5.1.1 Conventional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.1.2 Hybrid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525.1.3 Conclusions regarding CAPEX . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

5.2 OPEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535.2.1 Pumping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535.2.2 Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545.2.3 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555.2.4 Conclusion regarding OPEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

6 Creativity & Group Process Methods 576.1 Team division, process tools and results . . . . . . . . . . . . . . . . . . . . . . . . . 576.2 Creativity tools and results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 606.3 Process planning and results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

6.3.1 Overall planning and deadlines . . . . . . . . . . . . . . . . . . . . . . . . . . 616.3.2 Work division . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

7 Conclusions & Recommendations 63

List of Symbols 66

A Unit sizing 67A.1 Contactor (C-101) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67A.2 Vessel sizing (V201, V202 & V203) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68A.3 Heat exchangers (E-201,202 & 203) . . . . . . . . . . . . . . . . . . . . . . . . . . . 69A.4 Still Column (C-201) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70A.5 Pumps (P-101 A/B and 202 A/B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70A.6 Pervaporation membrane module (S-202) . . . . . . . . . . . . . . . . . . . . . . . . 70

B Used graphs 73

C Flow sheet conventional design 77

D Stream Summary - Conventional Design Case 79

E Stream Summary - Turndown Case 83

F Microwave heating model 87

G Split flow model 89

H Model used for hybrid system 91

I Stream Summary - Hybrid: Design Flow 93

J Stream Summary - Hybrid: Turndown Case 97

K Stream Summary - Hybrid: Max Flow Case 101

L HAZOP and FEI 105

M Equipment Summary 109

Bibliography 135

1Introduction and Project Charter

In this first section of the project, it will be described the background of the process as well as theobjectives and requirements of the dehydration unit for the natural gas. Moreover, all relevant datanecessary for further understanding of the process and design will be also displayed.

1.1. BackgroundDuring the last 40 years, the production of natural gas has increased by more than a factor 3, resultingin a fast increase of the amount and size of production plants. This, plus the on going scarcity of oil andgas, forces companies to place drilling platforms on more remote and violent locations. These offshoreplatforms, where huge feeds of oil and gas are processed, must operate with as few equipment aspossible to avoid the extra weight, trying to keep the production as cheap as possible.

In 2010, 4.359 billion (4395·10 ) cubic meters of natural gas were produced worldwide. Norway issituated 2nd in the ranking of biggest natural gas producing countries with a production of 114.7 billioncubic meters. In 2010, production of crude oil, Natural Gas and pipeline services accounted for 50%of the export value of Norway and 21% of the GDP (gross domestic product). All of the oil and naturalgas fields in Norway are located subsea on the Norwegian Continental Shelf, being the Troll field thelargest single one, representing one-third of the country’s natural gas production. When natural gas istaken out of the ground it needs to be processed before it can be used commercially. A conventionalgas sweetening process is displayed in figure 1.1.

Figure 1.1: Simplified liquid natural gas plant diagram. Here the purple block indicates the gas well,the blue ones indicate process steps and the orange ones are the products of this industry.

1

2 1. Introduction and Project Charter

Natural gas that comes out of a well is saturated water. It often also contains other compoundssuch as Hydrogen Sulfide, souring the gas. These components must be removed following the schemeof figure 1.1. Moreover, several crucial reasons why water need to be taken out are presented below:

• It can trigger the production of hydrates and of crystals. When transport of the natural gas islead through long pipes, the chance of clogging becomes high and the removal of these plugs isexpensive.

• Water can cause corrosion to the pipelines.

• It can cause slugging flow conditions which increases the pressure drop over the pipeline.

• In presence of water, the heating value of gas decreases radically. [1] [2] [3]

One of the most used dehydration processes is Glycol dehydration, with about 30,000 units inoperation in the USA alone. This method can be performed with any Glycol solvent, but the mostlytri-ethylene glycol (TEG) is used. This process started to be used in the 1970’s and has not changedmuch since. In a contactor column of perforated trays or a packing, the wet gas stream and the TEGstream will meet in counter current. After absorption the TEG rich in water goes to a regenerator,where the water is taken out in a still column. The pressure difference between these two processesis usually very high, going from 160-170 bar to atmospheric.

As mentioned before, the dehydration of Natural Gas using TEG has been used for over 40 years.Not much has changed to the way this process works over all the years. However, with a growinginterest in process intensification and many developments in this field, it could be possible to decreasethe size of the TEG unit while maintaining or even increasing the effectiveness.

Parts of the system in which a potential weight loss can be significant are the TEG inventory andthe size of the regeneration system. Examples of techniques that will be looked into are pervaporationmembranes and microwave heating, among others, having the potential to reduce the size and priceof the unit significantly.

1.2. ObjectivesThe assignment, provided by Frames group, is to find and design a new dehydration unit by introducingnew innovations in order to lower the CAPEX, OPEX and weight of the conventional TEG dehydrationunit for an offshore platform using recent advances in science.

Therefore, the first task that needs to be done is the definition of the conventional process.Then,the CAPEX, OPEX and weight of it will be set as benchmark. In the next stage, improvements will beproposed and their impact will be estimated especially in terms of CAPEX, OPEX and weight. Finally,conclusions and remarks will be posed about the proposed design of the unit.

1.3. Concept Stage 3

1.3. Concept Stage1.3.1. Process synthesisThe typical process for dehydration of wet natural gas can be simplified by splitting it in two parts, asshown in figure 1.2.

The first part is where the actual absorption takes place. Lean water-free Glycol is contacted withwet Natural Gas in a contactor where the Glycol removes the water from the gas. Then, after thisabsorption, the dry gas rich in Methane is sent for downstream processing, whereas the rich TEGneeds to be dehydrated and purified for reuse. From the regeneration subsystem also some overheadand waste streams are formed, that then will be treated. However, this part is out of the scope of thisproject.

Figure 1.2: Block diagram of the process. Orange blocks represent the battery limits of thedehydration process whereas blue blocks represent steps taken in TEG dehydration.

Hence, the battery limits of the unit are represented by the four orange circles shown in figure 1.2.There is only one inlet flow to the system, wet gas, and three outlet flows, dry gas product, drain andoverhead gases.

1.3.2. RequirementsThe requirements for natural gas after dehydration are presented in table 1.1.

Table 1.1: List of requirements as provided by Frames group

Location Offshore fixed platform in NorwayWater specification 24 mg/Sm

Turndown 10%Pressure drop ≤ 0.25 bar

Glycol losses contactor ≤ 10 l/MMNm (0.07 UGS/MMSCF)Others No mercury

Notes. S= Standard Conditions of 1 bar and 15 °CN= Normal Conditions of 1 bar and 0 °C.(As agreed with Frames during Kick-off meeting)

Although the implementation will be on a Norwegian offshore oil plant, the host country regulationswill not be taken into account and the extra costs that come from the installation being on an offshorelocation need not have to be considered as this difference works for both the conventional and thesuggested processes.


1.3.3. Plant capacity and locationThe capacity of the plant will be 380617 kg/h of wet natural gas which comes as feed stream to theunit. Once the mass balance and streams study is completed, it results that the plant will producearound 340000 kg/h of dry gas which includes small amount of water (24 mg/Sm3) coming out of theunit. This means that 2594 kg/h (purity wt 99.4%) of lean TEG are needed to absorb the 131 kg/h ofwater which needs to be removed. Given that the expected results are subject to 10% of turn down,the capacity of the plant must hold these fluctuations too.

Figure 1.3: Norwegian geographical map,green areas are open for petroleum and gasplatforms, red and orange are considered to

be opened for industrial uses [4]

The TEG dehydration unit will be located in theEuropean country Norway, specifically in an offshoreplatform of its coasts situated in the North Sea. Asshown in figure 1.3 the whole western part of the Nor-wegian coast in the North Sea is open for petroleumand gas industry.

Norway is the world’s second biggest exporter ofnatural gas and the fifth biggest exporter of oil, atthe same trying to become one of the world’s mostenvironmentally friendly industries in this field. Thiscountry has high pollution standards and there is con-tinued work on reducing emissions and avoiding ac-cidents or spills. This sector is vital for the country’seconomy, representing about 25% of the gross do-mestic product, 30% of the state income, more than50% of export earnings and providing approximately250,000 jobs, directly and indirectly. In addition, thisindustry not only helps to its own wealth fare, but alsois a very important contributor for the innovation andtechnological development in other related sectors.[5]

Norway has been producing gas for about 40 years,but at this moment its production has lowered till 20%of its highest peak. The development in natural gasexports from facilities on the Norwegian ContinentalShelf (NCS) has drastically decreased as reported by

the Norwegian Petroleum Directorate (NPD) from 2006 to 2013. [6] The natural gas extraction hasreduced total sales gas volumes with around 4% relative to what was exported from the productioninstallations. In spite of this trend, optimism is present because of the discovery of new reserves, evenin mature areas. Together, these will amount to 400-600 million barrels of oil equivalents allowing newprojects in Norwegian waters in the next 10-15 years.

Although the production costs are relatively high in the North sea, the quality of the oil and gas,the political stability of the region, and the close proximity to important markets in western Europe hasmade it an important oil and gas producing region. The largest natural gas field in the North Sea, theTroll gas field, lies in the Norwegian trench dropping over 300 metres. This required the constructionof the enormous Troll A platform to access it. Besides it, in the Ekofisk oil field, the Statfjord platformis also notable as it was the cause of the first pipeline to span the Norwegian trench.

The average air temperature in summer is 17°C while it is 6°C during the winter. The averagetemperatures have been trending higher since 1988, which has been attributed to climate change. Airtemperatures in January range on average between 0 to 4°C and in July between 13 to 18°C. Thesalinity averages between 34 to 35 grams of salt per litre of water, having its highest variability wherethere is fresh water inflow, such as at the Rhine and Elbe estuaries, the Baltic Sea exit and along thecoast of Norway.

With growing demand for improved gas technology, this field is suitable to process intensification.As stated in the Petroleum White Paper, the Government has confirmed the strategy for developing thepetroleum and gas with a proactive, parallel commitment to increased recovery from production fields,developing commercial/profitable discoveries, exploring in open acreage and opening up new areas.

1.4. Database 5

1.4. DatabaseIn this section of the project, all relevant data of the compounds involved is tabulated. This is also thedata that is used in the simulations.

1.4.1. Component listIn this project only three different species are observed. TEG, natural gas and water. The natural gascoming out of the well consist of the components shown in table 1.2. The properties of the differentspecies are discussed later in this section.

Table 1.2: List of components in Natural gas provided by Frames

Component name Mol. %H O @saturationN 0.18CO 3.58

Methane (CH ) 86.49Ethane (C H ) 5.33Propane (C H ) 2.18i-Butane (C H ) 0.49n-Butane (C H ) 0.89i-Pentane (C H ) 0.25n-Pentane (C H ) 0.24

C + 0.33

1.4.2. Component and thermodynamic properties

Table 1.3: Component and thermodynamic properties of Triethylene Glycol and water

Property Value TEG Value waterMolecular Formula C H O H OMolecular Weight 150.17kg/kmol [7] 18 kg/kmolBoiling Point 285 °C[8] @ 1 atm 100 °C @1 atmMelting Point -7 °C [8] 0 °C @ 1 atmDensity 1127.4 m @ 15 °C [8] 998.3 kg/m @ 200 °C[9]Viscosity 0.00478 Pa.s @ 200 °C[8] 0.001003 Pa.s @ 200 °C [9]

Vapour Pressure <0.001 kPa [7] 2337 Pa @ 200 °C [9]Heat of Vaporisation 61.04 kJ/mol @ 1 atm [8] 2257 kJ/kg @ 1 atm[10]

Triethylene Glycol (TEG)TEG is the water absorbing species in this system. It is a colorless, viscous liquid, well known forits hygroscopic properties and its ability for dehumidifying fluids. It is used especially as a desiccantfor dehydration of Natural gas. It will however degrade when the temperature rises above 204 °C,this makes good temperature control important and hotspots should be avoided. It’s thermodynamicproperties can be found in table 1.3.

WaterWater is the universal solvent. Industrially, water has been used for many purposes, especially forcooling. The natural gas obtained from wells is saturated with water which needs to be removed due


to the reasons mentioned in section 1. The thermodynamic properties of water are also listed in table1.3

Natural gas

Table 1.4: Component and thermodynamic properties of natural gas

Property Value natural gasMolecular Formula 86.49% CHMolecular Weight 19.5 kg/kmol (Frames specified)Density [11] 0.79-0.9 kg/m @ STP

Net Heating Value [11] 46054800 J/kg (11000 kcal/kg)

Natural gas, consisting of predominantly Methane, is a hydrocarbon gas formed due to fossilizationof buried plants and animals. For these species to become natural gas they were below the earthssurface for over a thousand years. It is a non-renewable source of energy and is typically used forheating (industrial) and cooking (domestic). Some of the properties of Natural gas are given in table1.4. The specification of the natural gas that comes from the specific well in Norway are given in table1.2.

2Conventional Process

In this chapter the conventional process currently used in the industry to dehydrate natural gas isdescribed. Firstly a process scheme is shown and later every step is explained into detail. A fewremarks on how this process is modelled in Aspen Hysys are given. All equipment sizing is explainedand a safety assessment is done. Lastly a few comments on bottlenecks and areas to improve will bementioned.

2.1. Process descriptionIn this section the conventional process for dehydration using TEG widely used in industries is describedwith all details taking into consideration the technical and feed requirements stated. These will beused to define the conventional benchmark as well as rooms for improvement in the different piecesof equipment. The conventional process is depicted in figure 2.1.

Figure 2.1: Flowsheet of currently used TEG dehydration process. In green the Absorption unit(U100) and in purple the Regeneration unit (U200).

7

8 2. Conventional Process

2.1.1. Contactor (C101)Streams in: Wet gas <102>, Lean TEG <103>. Streams out: Dry gas, Rich TEG <104>.

The absorption column, also called the contactor in this process, is the main piece of equipment ofa TEG dehydration process. In the absorption process, a liquid is used to contact wet gas and removethe water vapor. With absorption, the water content in the gas stream is dissolved in a relatively pureliquid solvent stream. To achieve this it is necessary to create a surface area as large as possiblebetween the two phases. This can be achieved using several pieces of internal equipment, such as:

• Division into trays.

• Random packing.

• Structured packing.

Trays

Figure 2.2: Typicalbubble cap platecolumn for TEGdehydrationcontractor[12]

One way to achieve a high surface area between the two phases is to dividethe column into trays as displayed in figure 2.2. Gas flows from below each traythrough bubble caps, which ensures the formation of small bubbles of gas. Eachtray is filled with liquid glycol which accumulates due to an overflow wall at thetray. The small gas bubbles provide a large surface area which is needed forthe mass transfer. Because the bubbles rise relatively fast the contacting time isshort. Hence equilibrium is not reached. Therefore several trays are needed toreach the dehydration specifications for gas transport, usually 6 to 20 trays areused, spaced approximately 61 cm apart.[13]

Random packingVarious types of random packing are also used in glycol contactors to achieve ahigh surface area for mass transfer. The total height of the packing in the vesselcan be calculated from the number of theoretical stages used in the design.Typically suppliers of the packings have correlations for packing height neededper theoretical stage.

Structured PackingStructured packing is to load the column with arrangements of steel internalsover which the glycol flows downward. The gas flows upward through the pack-

ing and has a large contact area with the glycol. This provides a very efficient way for mass transfer tooccur and is therefore used the most throughout offshore dehydration[13]. Just as in random packing,suppliers have developed a relationship between the packing height needed and the number of theo-retical stages. When designing the column it is essential that the glycol is distributed evenly over thetop of the packing, to ensure a good mass transfer area. A typical structured packing is displayed infigure 2.3.

Usually a structured packing is used as it provides the best mass transfer surface area compared torandom packing and tray columns. A larger surface area provides a better mass transfer and thereforea smaller column. The wet gas is fed at the bottom of the column and dry gas leaves the top. At thetop the lean glycol is fed and the rich glycol will be returned below the wet gas feed.

2.1. Process description 9

Figure 2.3: Typical structured packing used in the industry[14]

2.1.2. Flash (V201)Streams in: From HX (E201) <203>, Streams out: Drain, OVHD & to filters (S201) <205>.(The stream numbers depicted refer to Figure C.1 in Appendix C)Due to the high pressure used in the contactor some gas is physically dissolved in the liquid glycol. Thehigher the pressure in the contactor, the more gas dissolves in the liquid. A flash tank is needed to takethat portion of gas out of the liquid. The liquid first gets heated in the still column and afterwards it isdepressurised in the flash tank. With these changes the gases evolve from the glycol in the gas tank.It is designed as a three-phase separator to help remove any condensate in the liquid and thereforeincrease the lifetime of the downstream filters.

2.1.3. Filters (S201)Streams in: From flash (V201) <205>, Streams out: to HX (E202) <206>.

To prevent clogging and optimal conditions for glycol it is very important to keep the glycol as cleanas possible. Impurities might also cause foaming in the still or contactor. Therefore filters are installedto take out impurities. Particle filter are usually in operation all the time to take out any condensate inthe liquid. Carbon filters can be bypassed most of the time and will be installed on stream, if there areno hydrocarbons in the stream.

2.1.4. Reboiler (V202) & Still column (C201)Streams in: From HX (E202) <207> & OVHD, Streams out: to OVHD & to Surge <208>.

The rich glycol is preheated through heat exchange with the lean glycol leaving the reboiler andenters the top of the still column. By taking the temperature near the boiling point of glycol the glycolrelease the absorbed water and any other compounds until a purity of 99.4% is reached. The reboileris heated through a fire tube in which natural gas, sometimes from the flash, is burned. The reboilerand the still run at near atmospheric pressures.

2.1.5. Stripping column (C202)Streams in: From reboiler (V202), Streams out: To Surge (V203).

A stripping column is inserted between the reboiler and surge to achieve the highest purity possible.As stripping gas the gas phase from the flash vessel is used. A part of the water will dissolve in thegas phase and be taken out to overhead treatment. The opposite happens from what is happening inthe contactor.


2.1.6. Surge (V203)Streams in: From Stripping (C202), Streams out: To booster pump (P201) <210>.

Due to the fluctuations in the gas feed, the circulation might not always be even. A surge drum isinstalled to allow for these fluctuations and to achieve a constant recirculation of TEG. An additionalbenefit is the fact that it can be used as a check to see if everything is still working correctly. Whenthe level is significant lower then the needed of the vessel either a leak or holdup is present in thesystem.

2.2. Mass and energy balanceThe inlet wet Natural gas flow for the design case is given to be 380617 kg/hr at 156.5 bar(a) and 35 °C, the outlet dry gas water fraction and the glycol loses must be lower then 24 mg/Sm , as described inTable 1.1. From the above information, the quantity of water required to be removed in the design caseand in the turndown case were calculated. For systematic design of the Dehydration unit,a step-wisemethod given by Campbell [15] was used. It consists of following steps:

• Calculation of TEG concentration: The minimum concentration of lean TEG required for dehy-dration of natural gas was calculated by first estimating the dew point of the outlet dry gas atgiven conditions from the water content in natural gas v/s water dew point graph available in[15] and figure B.2. From the calculated dew point, the concentration of lean TEG required wascalculated from the equilibrium dew point v/s inlet gas temperature graph available in [15] andfigure B.1.From this procedure, we find that the minimum concentration of the lean TEG requiredfor our case is 99.2% wt.

• Calculation of lean TEG circulation rate: From the knowledge of the water content in and targetedwater content out of the contactor, the TEG circulation rate was calculated by considering a ratio20 kg TEG/ kg water removed for a number of theoretical stages of N=1.5. This ratio was agreedupon during the BOD meeting with Frames. The number of stages were chosen taking intoaccount that most TEG contactors work with 6 actual trays (tray efficiency is considered to be0.25). The circulation rate for TEG was calculated to be around 2594 kg/hr for the design caseusing this method.

In the regeneration section, the stripper column was assumed to have 3 stages.This was assumedtaking into consideration that normally the stripper column(or still column) has a lower numberof stages than the contactor.

The exhaust gas from the flash is also diverted to the stripping column so as to aid in removing waterfrom rich TEG.It enters the stripping column via the reboiler. Before it enters the reboiler, it is contactedwith outgoing hot TEG. For determining the pressure of the flash drum,the still top was assumed tobe at 1 bar and subsequently heat exchanger pressure drops(0.5 bar each) were added. This gavearound 4 bar operating pressure for the flash drum including some margin.

2.2.1. Simulation on Aspen HysysUsing the background calculations as basis, the process was simulated for design and turndown casein Aspen Hysys platform using the Glycol Package for thermodynamic calculations. This package waschosen as it is highly recommended for systems involving dehydration of gas with TEG. The followingobservations were made during simulation:

• The concentration of TEG from the regeneration increased to 99.4% on simulation and so to beconsistent, the lean TEG concentration of 99.4% was used for the complete simulation. The totalstream summary can be found in appendix C.

• It was argued that by decreasing the TEG flow proportionately for a 10% turndown would causecavitation in pumps and may even lead to weeping in the regeneration column. Therefore, thelean TEG flow for the turndown case was maintained at 33% (which corresponds to 877 kg/hr).The total stream summary can be found in appendix E.

2.3. Equipment sizing 11

Energy demandsFrom the Aspen Hysys simulations the energy demands in pumping and heating can be found.

Table 2.1: Energy demands per type

Location Type Energy duty [kW]P101 Electrical energy 13.4P202 Electrical energy 0.155Reboiler Gas heating 191.5Total 205.055

CoolingE203 Sea water cooler -103.5C201 TEG Condenser -49.85Total -153.35

Heat exchangerE201 HX 88.5E202 HX 168.5

2.3. Equipment sizingAll sizing presented in this section has been done following the methods described in appendix A. Everysize is reported tabulated and with equipment name. Vessel weight estimation have been preformedusing the method described in Sieder et al[16]. There it is estimated that vessel weight depends onwall thickness of the shell, assuming the shell to be evenly thick throughout the vessel.

𝑊 = 𝜋(𝐷 + 𝑡 )(𝐿 + 0.8𝐷 )𝑡 𝜌 (2.1)

With:L = length of vessel [m]𝐷 = Diameter of the vessel [m]𝜌 = Density [kg/m ]𝑡 = Wall thickness [m]

Heat exchanger weights are estimated using Aspen Hysys. Only motor weights have been used toestimate weight of pumps[17].

Contactor

Table 2.2: Size and weight comparison of the conventional contactor column

Name Type Diameter [m] Height [m] Wall Thickness [mm] Weight [kg]C-101 Column 2.04 12.2 190 143135


Vessels

Table 2.3: Vessel volumes

Name Type Volume Diameter Length Wall Thickness Weight[m ] [m] [m] [mm] [kg]

V-201 Flash 0.535 0.554 2.217 6 221V-202 Reboiler 0.465 0.529 2.117 6 202V-203 Surge 1.16 0.719 2.875 6 371

Heat exchangers

Table 2.4: Total surface area needed per heat exchanger

Heat exchanger Surface area [m ] Weight [kg]E-201 28.45 1253E-202 147.0 3390E-203 17.3 800

Basis and method of calculation of the area of heat exchanger is given in Appendix A Section

Still column

Table 2.5: Size of the conventional still column

Name Type Diameter [m] Height [m] Wall Thickness [mm] Weight [kg]C-201 Still column 0.28 6.5 10 476

Stripping Column

Table 2.6: Size of the conventional stripping column between the reboiler and the surge

Name Type Diameter [m] Height [m] Wall Thickness [mm] Weight [kg]C-202 Stripping column 0.25 0.5 6 32

Pumps

Table 2.7: Power requirement per pump

Pump Head [mlc] Power [kW] Weight [kg]P-101A/B 1370 13.4 564P-202A/B 20 0.155 22

2.4. Total weightAdding all the weights of the separate pieces of equipment together, a total weight for the whole unitcan be estimated. In the case of the conventional process, this weight is estimated to be 150466 kg.This is the dead weight of the unit without the weight of piping and the weight of the framework wherethe unit is build.

2.5. Health, Safety & Environment 13

2.5. Health, Safety & Environment2.5.1. Preliminary study of risksOne of the major points of the project is the analysis of risks and dangers arising from the unit. Inorder to reduce them from a process design point of view the Dow’s Fire and Explosion Index (FEI)has been performed on the absorber unit in the process. In addition, an analysis of the hazards of thecompounds present in the system as well as the possible waste generated was also carried.

The two major two flows present in the system are triethylene glycol and natural gas, describedbelow.

Triethylene Glycol

Figure 2.4: Safety of TEG

Some of the most important properties of triethylene glycol(TEG) regarding safety are stated in table 2.8, where onecan appreciate that the boiling point is really high as wellas the auto-ignition temperature, reducing its risk.

Furthermore, there will be no explosion danger andthere is little toxicity danger, as shown in figure 2.4. Re-lease of TEG into in the environment should be avoided asmuch as possible, because the products of its biodegrada-tion are more toxic than TEG itself. Moreover, in the caseof leak, the TEG should be diluted with water and absorbed into an inert material, whereas in the caseof fire, the fire should be extinguished with powder, water spray or foam. No water jet should be used.Contact with heat sources should be avoided. Finally, direct contact with TEG should be avoided. Whenin contact with eyes or digested a doctor should be contacted.

Table 2.8: List of properties for TEG [18]

Properties of TEG ValueBoiling point 285 CAuto-ignition temperature 371 CFlash point Closed cup 177 C

Open cup 165 CFlammable limit Upper limit 0.9 %

Lower limit 9.2 %LD (oral) 4700 mg/kgTLV 10 ml/m

Natural gas

Figure 2.5: Safety of natural gas

Natural gas is highly flammable, creating the risk of explo-sions, as can be seen in figure 2.5. Table 2.9 shows theexplosion limits of methane, which is a key component ofnatural gas. A fire can not be extinguished unless the sourceof the gas has been closed. So, it is advisable to let all thegas burn up and then extinguish the fire with dry chemicals,foam or CO .

In addition, when the gas is kept under pressure it can lead to the risk of frostbite, which occurswhen high-pressure gas is released, expanding and cooling down. This is however more dangerouswhen handling liquefied gas, but in this system the natural gas remains in the gas phase. The gas isnot toxic but when released can be highly dangerous because it can cause asphyxiation by drawingout all the oxygen. It has been found that up to concentrations of 10 000 ppm no physical changesoccur when a human is exposed. Studies have shown that there are some physical complications intest animals who are exposed to high concentrations of methane (up to 70%) while having enough


oxygen, but not much has been documented on these phenomenon and it seems unlikely that thesecircumstances will occur on the plant.[19]

Table 2.9: Explosion limits of methane (key component in natural gas)[20]

Properties of methane ValueExplosion limits Lower 5%

Upper 15%

Health, Safety and Environment assessmentIn conclusion, both components in the system are not extremely toxic. Good ventilation is importantto prevent a build up of natural gas in closed spaces because this can lead to asphyxiation.

Then, natural gas should not end up in the environment, hence if natural gas needs to be disposedof, it should be burned, leading to mostly H O and CO . A danger of high concentrations of CO is thatit is heavier than oxygen and can therefor accumulate at the surface. This can cause asphyxiation.Also, although TEG is not very toxic, the products of the degradation are. The liquid TEG needs to getdiluted with water and then absorbed into an inert and collected. When this is done, what remains canbe diluted again and disposed of through the waste water system.

Finally, the conditions at which the system operates are relatively mild. The highest temperaturereached will be around 200 °C. Only one recorded incident has been found. In may 2013 in Spain afire occurred after TEG was added via the TEG inlet. The TEG inlet was aimed at a hot spot and theTEG vapor caught fire. It was only reported as a level 1 emergency shut down. [21]

If TEG or natural gas leak from the system, the chance of it reaching a hot surface or an ignitionspot should be decreased as much as possible. Another big risk comes with the high pressure in theabsorption tower. When the vessel or piping at high pressure breaks, it can result in an explosionand both TEG and Natural gas can be released. The sudden expansion of the natural gas can causefrostbite. Also the chance of an explosion of natural gas will increase in these conditions, resulting inbig amount of natural gas released in a very short time.

In addition to the HSE assessment, a bow tie diagram has been made, shown in figure 2.6. For this,it was selected that the high pressure of 156.5 bar in the contactor is the most hazardous conditionpresent in the process and the selected top event is a rupture in the wall of the contactor. The bow tiecan be used to identify threats that increase the chance of the top event happening. It also containsthe consequences of that top event. Also barriers to decrease the treats and the consequences of thetop event are added.

2.5.2. Dow’s Fire and Explosion Index (F&EI)In order to classify the risk of the dehydration process, a fire and explosion index has been made. Thetabel with assigned values and the final F&EI can be found in appendix L

The two species in the system that are capable of creating a fire or explosion are TEG and naturalgas. Because natural gas exists of multiple species, the properties of methane have been used, sincethe largest part of natural gas consists of this. The information needed for the F&EI is in table L.1.

For the F&EI the material with the highest Material Factor(MF) needs to be used for the calculations.In this case this will be the natural gas because the methane has an MF of 21. Also the unit whichwill be looked at needs to be specified, in this case the contactor. The species present in this unit arenatural gas, TEG and water.

Base factorsThis subject is cut into multiple items. The only items which get a penalty are: Material Handlingand Transfer, Access and Drainage and Spill Control. These items get penalties because of the highlyflammable nature of natural gas, the inaccessibility of an offshore platform and the difficulty in im-

2.5. Health, Safety & Environment 15

Figure2.6:Bowtie


Table 2.10: List of properties of TEG and Methane for determining the F&EI

Properties TEG MethaneMaterial Factor 4 21

H 9.3·10 21.5·10N 1 1N 1 4N 0 0

Flash point 350 °F GasBoiling point 546 °F -258 °F

plementing a draining system and prevention measures for spills. The total penalty adds up to be2.70.

Special process hazardsSome of the items that got a penalty in this subject were the pressure, which is high in the contactor,which receives a penalty of 0.48. Also the quantity of flammable material got a high penalty, 3. Thetotal penalty for Special Process Hazards adds up to 5.18.

ConclusionThe final Fire & explosion index turns out to be 294 which categorizes this unit in the severe degree ofhazard region. The exposure radius for this F&EI will be 70 m. This will mean that a large part of theplatform will be affected by an explosion. There are no structures around the platform which makesthe consequences for second parties minimal.

Loss control credit factorsThe fire and explosion index can be reduced when measures against fire and explosions are present.Therefor a few thinks need to be present in the final design of the unit itself and the surrounding plant

• Emergency power

In case of an emergency there can be a power outage, it can be possible to automatically go toemergency energy. If we have a power outage there will be no drying of the gas anymore butthere will be no possibility for for instance a runaway reaction or agitation for which it might benecessary to have a big emergency supply of energy.

• Cooling

Our system does now only have one cooling device and no backup, but because there is nochemical reaction in our system but only separation the consequences of losing a cooler will notdirectly cause a fire or explosion.

• Emergency shutdown

If something abnormal happens the entire system should be shut down completely. If this hap-pens automatically than the reduction of the F&EI is bigger than when it only sounds an alarm.

• Computer control

The bigger part of the system is controlled via computers, the more reduction is given to thesystem. The more advanced the system the better.

Material isolation credit factorIn this section items that prevent the build up or spilling of material to places where they should notbe, both within or outside the system.

2.6. Bottlenecks and possible improvements 17

• Remote Control Valves

These are valves that can isolate different sections of the process. This can prevent spreading ofhazardous material or fire.

• Dump/Blow-down

This means that there is a vent with flair present in case the natural gas present needs to bereleased. Also a way to remove the TEG from the system should be present.

• Drainage

On land the ground has to have a slope of 2% that leads to a drainage trench. This will be moredifficult on a platform since we will not have much space for draining reservoirs.

• Interlocks

Thee prevent incorrect material flows within the system.

Fire protection credit factorsThese are things that should be present on a plant in case a fire breaks out.

• Leak detection

Gas detectors should be present on the plant. These need to sound an alarm, and even betterwould automatically start the protective system to prevent a fire or explosion.

• Structural steel

The weight bearing steel steel needs to be fireproofed.

• Fire extinguishing

On the offshore plant enough water will be present. Only thing extra needed are pumps that cancreate enough water pressure. If the fire is burning on TEG it should be extinguished with COor foam. This requires a special system. There should be an automatic water or foam sprinklersystem present.

• Hand extinguishers/monitors

There should be an adequate supply of hand extinguishers present on the plant. These will haveno effect when the fire is from a big spill.

• Cable protection

The cables needed for the equipment are vulnerable to fire and need extra protection. Theseshould not be forgotten when the plant is set up.

2.5.3. WasteThere are two waste streams leaving the TEG dehydration system, both from the regeneration unit.One is a liquid outflow from the flash equipment which will prevent buildup from unwanted species.The second one is a combination of the vapour gas outflow from the flash and the water rich outflowfrom the separation units (still column and pervaporation membranes). Because this specific unit is onan offshore gas platform, using a flair to burn the waist would be too dangerous. Therefore, all wastestreams will be incinerated.

2.6. Bottlenecks and possible improvementsThe requirement in offshore engineering is striving for the lightest and smallest equipment as a gainin weight will have an effect on the total investment for a platform. The biggest piece and heaviestpiece of equipment is the absorption column (C101). As only approximately 40% of a typical contactorcolumn consist of the packing and transfer area and the rest is filled with equipment and spargers it isnot expected that a large weight gain can be achieved there.


Thus, it was identified that the majority of changes according to the objectives of the project canbe done in the regeneration subsystem, because it contains more pieces of equipment, almost all theTEG stored and the conditions on the TEG are more strict in this section (i.e. 150-200 °C). For thesereasons the focus of the alternative technologies will be in this unit of the system.

Furthermore, the TEG inventory and regeneration loop can provide also some weight loss. By usinga more effective separation in the contactor the TEG circulation rate can be lowered. This leads thento a reduction of TEG inventory, which leads to smaller equipment especially in the form of the reboilerand the surge (V-202) & (V-203), with volume of respectively 0.667 m and 1.16m . This will lead toa weight reduction as less steal is needed. Also different techniques of TEG dehydration need to beconsidered to reduce the size and costs of the total regeneration loop.

Finally, the biggest energy demand is identified from the reboiler which requires 194 kW to runefficiently. Also the injection pump of 13.4 kW contributes to the total energy demand. By reducingboth, the total operational costs can be cut down and more efficient and cheap operations can be carriedout. This reduction in energy demands can also be achieved using a completely different technique ofTEG dehydration, as mentioned before.

In the next chapters recent advances from science will be discussed and reviewed in order to checkits usability in this process. From these concepts, a new system will be then proposed and the possibleoptimization and improvements achieved will be calculated and reviewed.

3Innovation Map

All innovation and improvement opportunities are described in this chapter. First all considered alterna-tives are described in a technological and more qualitative way and their beneficial effects are touchedupon. After that a preliminary cut will be made to discard technologies which have too many down-sides. Later different process schemes are proposed and studied quantitatively and then researched forbeneficial effects on this system, regarding CAPEX, OPEX & weight. Here calculations and simulationsare tried upon the new technologies which were earlier proposed. Lastly the final system is chosenwhich will be modeled and designed in the rest of this report.

3.1. Description of alternativesCarrying out an analysis on the different parts of the TEG dehydration unit, it is clearly observed thatimprovements can be implemented in every piece of equipment such as the contactor, reboiler, stillcolumn, heat exchangers, flash vessel and/or pumps. A change of solvent for the dehydration processwas also considered, but it was decided to continue the optimization of the process with TEG, becauseit is the most used solvent used in the natural gas dehydration industry. Therefore, taking into accountnew advances and approaches in process engineering, an extensive research was made based ondifferent criteria (feasibility, applicability, cost, experience, effectiveness, weight and size), leading tothe descriptions and final selection of the more appropriate alternative for this process.

3.1.1. Improved TEG injectionThis technology basically splits the TEG inlet stream introducing the lean solvent in different stagesof the contactor column instead of only one. Hence, as there are multiple TEG injection points, leanTEG contacts wet gas earlier in the column, increasing the effectiveness of the water removal due to abetter mass transfer.

This option will not reduce too much the size of the contactor, because the packing (mass transferzone) only represents about 25% of the piece of equipment, but it might reduce the necessary inventoryof TEG and, therefore, the energy consumption, weight and costs.

An alternative TEG injection method is to use semi lean TEG out the reboiler, before the strippingcolumn. Injecting this semi lean TEG halfway the column, where there already is a lot of oxygenabsorbed in the TEG. This can lower the size and energy needed for reboiling and it will lower the sizeneeded for the surge. An extra injection pump however is needed to pressurise this semi lean TEG.

3.1.2. Microwave heatingMicrowaves are electromagnetic waves with a wavelength between 1 mm to 1 m. These microwavesaffect the dielectric molecules, which start re-orienting themselves and try to follow the direction ofthe field created by the waves. The friction that occurs because of this movement generates heat.

19

20 3. Innovation Map

Advantages of this technique are that there is no heat transfer zone so the heating occurs in the entirevolume that is being irradiated. The waves are selectively being absorbed and a rapid heating canoccur.

The dielectric component in the TEG regenerator is water, this is the species that needs to evaporateout of the TEG. This will also be the target specie of the microwaves generating the heat, which meansthat the water in the mixture can become warmer than the TEG, which will lead to faster evaporation.TEG however has an interaction with water molecules as it contains alcohol groups. This can lead tothe TEG heating up as well. No test regarding this specific process to check if only the water heats hasbeen done as of now. The molar fraction of water molecules of the feed stream is 32 mol%. Regardingthis high molar concentration it can be expected that there is a lot of contact between water and glcyoland therefor energy transfer. A different benefit is however, while there is no heat transfer area, thetotal volume of TEG and water can be heated at once and uniformly.

Figure 3.1: Microwave heating[22]

Experiments showed that only heating up the liquid will not benefit the separation of the binarymixture[22] and the stirring will also create a uniform temperature in the liquid phase which takesaway the advantages of the selective heating. However, when also the surface is irradiated withmicrowaves the separation of the more volatile species is more effective than in a separation withoutmicrowave heating. One explanation of this is that very locally high temperatures will occur, resultingin a smaller column with fewer trays. These so called ”hot-spots” can lead to a fouling in TEG, as TEGthermally degrades at temperatures above 210 C.[7] Discussion with professor Stankiewicz and Dr.Guido Sturm however provided a different outlook as they mentioned new ways of heating which wasvery controllable an predictable and therefor those hot-spots can be avoided.

The uniformity of microwave heating however is debatable. In literature it is described that byabsorption in the medium the intensity of the field will drop quickly. This leads to a large part of thevolume not heated and parts of the volume overly heated [23]. Dr. Guido Sturm mentioned howeverthat this effect can be reduced a lot, because the behaviour of microwaves can be described quitegood. By altering the field and radiation techniques these hot spots can be minimized. This is not doneon a larger scale then lab, but shows good promise.

The currents hurdles in the use of microwaves in industry are the yet unreliable scale up of theprocess, which can be helped by modeling the field and design it that way. Another hurdle is theimplementation of microwave equipment into conventional chemical equipment.

3.1.3. Super-X packingThe Super X-pack packing is an innovation which is fabricated to mimic fractal structures. These fractalstructures, shown in figure 3.2, are known to enhance transfer rates, leading to a decrease in TEGinventory. This packing could be beneficial in both the regenerator as well as in the absorber.

3.1. Description of alternatives 21

Figure 3.2: Nagaoka Corp. Super-X packing

The Nagaoka International Corporation, whichdeveloped the Super X-pack packing, made veryinteresting claims with the development of thistechnology. The company claimed a reduction ofthe pressure drop by a factor of 3, while the pack-ing reduced the height of the column by a factorof 5 compared to conventional column, achievingup to 80% energy saving [24].

However, despite these advantages, severeoperational problems were encountered, mostlydue to the packing getting clogged and fouled,which eventually lead to the stopping of the com-mercialisation of the packing.

3.1.4. Liquid turbochargersA turbocharger, is an induction device used to al-low more power to be produced by an engine ofany given size. A engine with a turbocharger canbe more efficient than a naturally aspirated en-gine, because the turbine forces more air, and proportionately more fuel, into the combustion chamberthan atmospheric pressure alone. [25]

Applied to process engineering it can be used to transfer pressure using kinetic energy. A high-pressure fluid or gas is used to drive a turbine which pressurises a low pressure liquid. Within TEGdehydration it can be used to pressurise the lean glycol heading for the contactor, by transferring theenergy available in the rich Glycol.

Figure 3.3: Liquid Turbocharger [26]

As 50% of the total cost of gas refining is represented by energy costs, the addition of a turbochargercan provide a significant cut down in operational costs. By using a liquid charger less investmentsneed to be done regarding pressurising the glycol, therefore a cut down in capital expenditure is alsoexpected. The company Energy Recovery claims an energy efficiency of up to 80%. On the otherhand, this technology reduces the degrees of freedom of the system, as it combines different streamsof the process. These Glycol powered pumps are currently sold skid mounted by companies such asKimray and Rotor-Tech.

3.1.5. Pervaporation membranesThis technology is itself a combination of two others. On the one hand it there is a permeation,transport through a membrane, on the other there is evaporation, changing its phase from the liquid


to the vapour phase (see figure 3.4). Therefore, the water of TEG-water mixture in our regenerationsystem might be taken out using a hydrophilic membrane as a selective barrier between the liquidphase feed and the vapour phase permeate allowing the desired molecules to diffuse through it byvaporization.

Figure 3.4: Pervaporation membrane for dehydration

One of its main benefits is not being a pressure driven process. Instead, the driving force is dueto a higher chemical potential on the feed side than on the permeate side. The gradient in chemicalpotential is then maximized by using high feed temperatures and low pressures on the permeate sideas well as combining polymer properties for membrane. [27].

By replacing distillation by the pervaporation membranes for the Glycol regeneration subsystem,according to Pervatech company savings up to 75% on regeneration equipment and 30 to 50% reduc-tion on energy usage can be achieved. However, membrane units, including the need for vacuum, arecurrently relatively expensive. Also, if the supply contains suspended matter or dissolved salts mem-brane pollution may be encountered. In this case, an effective pretreatment must be implemented.e.g. filtration.[28]

3.1.6. Molecular sieves + TEG unitMolecular sieves are usually installed in applications in which very low residual water content is required,such as ahead of a low temperature hydrocarbon extraction process. They are suitable for drying verysour natural gas that also contains aromatic compounds. However, heavier hydrocarbons might bedifficult to remove from the silica gel during the regeneration step. These solid compounds (silica gelor zeolites) used as molecular sieves are prepared as round or slightly elliptical beads having a diameterof about 4 to 6 mm. Each of these compounds has its own characteristic affinity and adsorptive capacityfor water, so a good selection is crucial in the process.[29]

While dehydration with Glycol is the most common process used to meet the water dew pointspecification for sale the gas, under certain conditions solid adsorbents are also used for this purpose.i.e. Molecular sieves are used for many offshore applications such as floaters (FPSO’s). The positiveside of molecular sieves is that they can handle wave-motions very well. The downside is the scaleand weight of the units.

A molecular sieve dehydration unit after a TEG dehydration unit, will be used for polishing andincreasing water removal efficiency. It will be able to achieve very low dew points which are requiredfor cryogenic plants. Additionally, molecular sieve units can also handle large flow variations as well ashigher inlet gas temperatures. However, they have higher initial capital investments, are way biggerand heavier than comparable Glycol units.

3.1. Description of alternatives 23

Figure 3.5: Molecular sieve for water adsorption

3.1.7. Addition of entrainerHeterogeneous azeotropic distillation is a widely used technique to separate non-ideal mixtures. Theprocedure is incorporating a new component (entrainer) in the system such as toluene or octane. Theentrainer will form a heterogeneous azeotrope with water of the initial mixture. Then, the azeotropehaving minimum boiling point goes to a decanter and splits in two liquid phases. The stream rich inthe entrainer is recycled back to the azeotropic column and the other water rich goes to treatment.

This azeotropic distillation has various advantages such as a high efficiency of separation, low refluxratio and a reduced heat energy and it can be a suitable solution for the regeneration part. However,adding a third component always increases the complexity of the separation. The gas-liquid compositiondistribution in the column is much more complicated than that in the usual one, and a stable operationof a distillation column is very difficult. It is also necessary to add more pieces of equipment for theentrainer recovery, resulting in a bigger and heavier unit.[30] [31]

3.1.8. Vacuum operation in still columnAt vacuum conditions the concentration of TEG obtained in the still column will be higher for thesame reboiler temperature used for atmospheric operation, as the boiling point decreases for the samerich solvent. Another possibility of vacuum operation, if not so pure TEG is required, is reducing thetemperature in the reboiler. In addition, it helps extend the useful life of the system Glycol.

However, reboilers are operated under vacuum conditions in rare cases due to its complexity, vacuumgeneration equipment and the fact that any air in the process may result in degradation of the TEG.Hence, it is usually cheaper to use stripping gas. [32]

3.1.9. Rotating packed beds (HiGee)Firstly described by Ramshaw and Mallinson[33], rotating bed reactors or HiGee (short for high gravity)distillation, have taken a large role in offshore oil dehydration. It is used widely in China and the benefitswere readily recognized by the American market and is currently being introduced there. The Europeanindustry however lacks behind regarding HiGee distillation.

By rotating the reactor the gravitational field increases 100-1000 times and therefore the shear flowis enhanced. The high centrifugal speeds allows for packing with relatively higher specific surface areaand achieves order(s) of magnitude higher gas liquid throughput and possible mass-transfer rates.[34]These factors lead to a significant reduction in size of conventional mass-transfer equipment such asabsorption and distillation towers. Ramshaw and Mallinson [33] claim achieving an up to 100-foldreduction in equipment size. Later experimental studies however tempered these claims and found an5-10 fold reduction in HETP [35] which is still an significant decrease in size.

The main downsides however are that moving parts are introduced which are more maintenancesensitive than conventional techniques. The inside rotating bed has a dynamic seal, which preventsthe gas from bypassing the rotor, but compromises the reliability and longevity due to its contact with


working fluid. Also, one unit can not be competent for continuous distillation owing to incapability offeeding the rotor at radial position, equivalent to middle plate of traditional distillation column. Thus twounits of rotating bed are required for continuous distillation; one as rectifying and the other stripping.

HiGee technology can both be used in the contactor part of the process as well as the TEG regener-ation. By using rotating bed reactors the size and weight of the contactor and still column and thereforthe total unit can decrease significantly.

Figure 3.6: HiGee distillation: (a) RPB integrated with reboiler and condenser; (b) RPB with off centerfeed and integrated with reboiler [34]

3.2. Selection of alternativesIn this case, from stated above it is decided to gather the information in a way such that it can becompiled and presented in a consistent, high visualization chart, showing the strengths and weaknessesof each application for each criteria, accompanied by focused comments from the team, resulting inthe selection table 3.1.

There is no such thing as one solution which fits all requirements when it comes to chemical solventrecycling or dehydration. Solutions are therefore necessarily hybrid in nature where a combinationof traditional and improved technologies is used. Each technology provides a part of the separationrequired within a customized sequence and overall methodology and further research must be carriedout in terms of OPEX, CAPEX and weight to determine the improvement of the alternative.

However, there are already five possible technologies that will be rejected directly. The first one willbe Super-X packing, because it is not being commercialized anymore, avoiding any possibility of its realimplementation. Secondly, the hybrid molecular sieve plus TEG unit is not going to be implementeddue to its weight and scale makes it not suitable for platform location, which is one of the requisites.

3.2. Selection of alternatives 25

Table 3.1: List of alternatives with strengths and weaknesses

Technology Strengths WeaknessesImproved TEG injection Less lean TEG inventory More complex design

No reduction of sizeMicrowave heating Direct energy coupling Design into conventional equipment

Volumetric heatingRapid and selective heating

Super-X Packing High transfer rates CloggingLess lean TEG inventory FoulingP drop column ↓ 3 times No commercializationHeight column ↓ 5 times No experience

Liquid Turbochargers Large energy saving Less system flexibilitySmaller OPEX Availability of companies

Pervaporation membranes 100% efficiency TEG-wat sep. ExpensiveSelectivity No solids allowed

30-50% energy saving Availability of companiesMolecular sieves + TEG unit High efficiency Expensive

Low dew points Higher CAPEXLarge flow variations Heavy & bigHigh inlet gas T

Addition of entrainer High separation efficiency More equipmentLow heat energy More components

Heavy & bigVacuum operation Less lean TEG inventory Complexity

High TEG purity More equipmentPossible TEG degradation

HiGee distillation High Efficiency Moving partsSmaller equipment (5-10 fold) Very unknown technology

More maintenance

Also, the addition of the entrainer is rejected as it will increase the size of the unit as well as it is not aninnovative solution, which is in conflict with the objectives of the project. Also earlier proposed toluenewill dissolve into TEG as well, working against all benefits as proposed earlier. Finally, the vacuumoperation in a conventional equipment setup in the regeneration part is not investigated anymore asan alternative, because to gain energy savings, the vacuum was meant to be created by ejectors thatwork with existing flash gases going out. However, this will result in a pressure drop avoiding thesegases to reach the flare header which takes them into the incineration flame. The HiGee distillationis discarded as the introduction of moving parts and such an unknown technology is hard to achieveoffshore. Several onshore application should be achieved first to look at the effects it will have on thestructure of the platform. If it will change the integrity of the drilling platform and question like thatneed to be answered first.

For the other four technologies, a full study and design was done, resulting in three combined newprocess schemes shown below, stating the several assumptions used in each.

3.2.1. Turbochargers and split-flow injectionTurbocharger and semi-lean split fraction techniques will be implemented together in each differentscheme, as they do not interfere with the other alternatives. A detailed scheme is provided below infigure 3.7.


Figure 3.7: Process scheme with turbocharger and semi-lean TEG split flow injection, shown in yellowboxes

TurbochargersThe size, and therefore weight, of the injection pump system can be lowered by using a turbocharger,because as mentioned, this device interchanges the energy of a high pressure stream with a lowpressure one. This can also decrease the total energy needed for the pumps as well as the number ofthem.

The total operational costs for pumping, assuming a total cost of 10 ct €per kWh[36], is 1.34 €perhour [37]. Assuming 24/7 operation the total costs per year of this pump will be € 11.738. Usingcalculation tools provided by Energy Recovery©a recovery of 70 % of energy can be achieved. Thiswill result in a evenly large reduction of operational costs. So a reduction of € 8.216 on a yearly basiscan be achieved. Not only that, also a reduction of 9.38 kW is achieved at the pumping section. Thisleads to a reduction of approximately 79.866 kg CO which is released on a yearly basis[38]. Thetotal energy requirement for the plant is 205 kW. By adding a liquid turbocharger into the conventionalprocess a reduction of 4,6 % can be achieved without increasing the capital expenses which will be areal benefit.

Split Flow injectionThis alternative is studied with an intention of reducing the TEG inventory in the recirculation system.Following is the discussion of the study.

The incoming lean TEG is fed to the top-most stage of the contactor. As per the design of theconventional process in section 2.2, the contactor has 6 theoretical stages, therefore, it is possible tostudy injection of TEG ranging from 2 to 6 splits, simultaneously varying the percentage of flow flowingthrough each split branch. However, it should be noted that while injections with 2 and 3 splits canbe studied extensively for symmetric arrangements between theoretical plates, for higher number ofsplits(eg:4-6) there would be too many combinations possible.


Hence, to restrict ourselves, we study only injections with 2 and 3 split flows with varying percentageof flow through each split branch. Since the intention is to reduce TEG inventory, simulation was startedwith lower conservative estimate for the lean TEG flow in order to check whether it is possible to stillachieve the desired specifications in the outlet dry gas. As it was found that it is indeed possible tomeet the outlet water requirements, all the simulations for split flow were started with lower estimateof TEG flow, that of 1580 kg/h. The maximum outlet water content as per specification turns out tobe 8.5 kg/h. If the specification was found to be well within limits, TEG flow was reduced even furtherfor the split flow to an extent that the outlet water concentration never rises above maximum 7.7 kg/h.On the other hand, if the specification was barely met, no further adjustments were done in that case.

Figure 3.8 summarizes the observations of the simulation modelled in Aspen Hysys G.1 which formthe basis of this study. Different types of splits were tested to see if adding more TEG in the beginningor end has an advantage. Entries in bold represent lowest possible flow of TEG that can be achievedfor that particular split combination to achieve the water specification as mentioned above.

Figure 3.8: Results of calculations on split flow injection made in Aspen Hysys.

It can be seen that the lowest achievable flow of lean TEG in both 2-split and 3-split schemes is1225 kg/h. There is no significant reduction of TEG on increasing the number of splits form 2 to 3. Tocheck whether this really adds value to the conventional process with no splits, the flow of lean TEGwas reduced to as low as possible in Hysys still ensuring that the above specs were met. This flow was


found to be 1150 kg/h. This is a result contradictory to our expectation that split flow reduces TEGinventory.

From the above study, it can also be seen that with Hysys simulations, it is possible to reducethe lean TEG flow even below the theoretical minimum of 12 times the amount of water removed.However,it must be understood that such reduction may not be practically feasible. Moreover, wecannot completely trust the thermodynamic models in Aspen Hysys to be totally accurate in theirprediction. Hence, we limit ourselves to the theoretical minimum flow of 12 times the water removedof lean TEG as mentioned above.

3.2.2. Alternative 1: Process scheme with microwave heatingThe improvements and changes suggested were then included into the conventional process of fig-ure 2.1, getting figure 3.9. This figure shows a still column heated by microwaves. The rest of theequipment basically remains the same.

Figure 3.9: Process scheme with microwave heating (yellow box)

Microwave heatingMicrowave heating has several benefits as mentioned before, including that it can be more efficientand requires a smaller device than conventional heating with a reboiler. In some cases it can even bereplaced in total. It can also decrease the amount of stages needed for the regeneration.

The technology for continuous operation is now in the pilot plant stage. The company Sairem(France) is working on this. Their reactor design has a flow capacity up to 1 L/min and has a microwavegenerator that generates waves of 2450 MHz. 6 kW of power is generated and there is a significant


part of the design devoted to cooling. The unit is a metallic vessel which assures pressure containmentand allows for fast thermal transfer.[39]

However, heating volatile, often flammable organic solvents, under well-controlled conditions isnot trivial on the large scale, but it can be done. Lastly, another Sairem 915 MHz batch reactorwas changed in the strategy to microwave scale-up through the use of a different wavelength, sincepenetration depths, dielectric constants and loss factors vary with wave length as well as solvent natureand temperature. In this case, the energy savings were due to a decrease in heating time and not inenergy efficiency, because normal household microwaves (central component of any microwave device)has an efficiency of 50-65% transforming electricity into electromagnetic irradiation[40]. However dr.Guido Sturm of TU Delft, a expert in microwave heating, mentioned an efficiency off up to 80 %.

Overall, there are reasons to think that together with the use of the stripping technique for glycolregeneration, with a gas normally flowing upward counter currently to the descending liquid TEG, theunit can achieve the requirements and reductions proposed. Depending on the stripping agent used,i.e. outlet gas from the flash (V201), water, hydrocarbons, or both are absorbed from the glycol intothe stripping gas, thus regenerating the glycol for reuse in dehydrating the natural gas. But the realityis that these processes produce an additional gaseous or aqueous waste stream that requires off-siteattention such as incineration, disposal, or further treatment.

An attempt has been made to model microwave in Aspen Hysys, but a working model is has not yetbeen achieved. The column is split into three stages, modeled as flashes and a condenser and reboilerpart. At each stage a specific temperature is set, as is used with microwave distillation. These are allseparately heated. The feed enters the column at the middle stage, this because it gave the lowestenergy use. This model however leads to very high and fluctuating energy demands per stage. Threedifferent settings were used. Firstly the natural gradient occurring in the still column has been taken.Secondly a linear decrease between the top and bottom stage has been tested and lastly the inverseof the natural gradient is tested. This is displayed in table 3.2 and the model used is added in appendixF.1.

Table 3.2: Energy demands from the different setting of the model described in appendix F.1

Setting 1 Setting 2

StageSetTemperature (C)

EnergyDemand (kW)

SetTemperature (C)

EnergyDemand (kW)

Condenser 97 -17.05 97 -60043 99.26 -162.6 125 59992 101.9 -16230 150 -30.851 150.7 16370 175 92.66Reboiler 204 192.8 204 87.83

Setting 3 Conventional

StageSetTemperature (C)

EnergyDemand (kW)

SetTemperature (C)

EnergyDemand (kW)

Condenser 97 -7139 97 -49.853 145 7136 - -2 165 32.69 - -1 185 63.91 - -Reboiler 204 55.17 204 191.5

As this model did not achieve realistic values different professionals in the field of modeling mi-crowave heated column were contacted. From these conversations, it became apparent that, as thisis a very young field of research no real simulation models are achieved as for now.

The main fields in which microwave heated columns are used are pharmaceutical and food process-ing technologies. Outside of these fields the benefits have not been sufficient enough to take the riskof entering a new technology. To estimate the costs, the energy needed by a conventional still columnis used.

When designing the new column a few constraints should be kept in mind however. No magnetic


materials can be used around microwave heated volumes. These magnetic properties cause extensiveheating effects on the magnetic walls and equipment. A still column made of carbon steel as proposedearlier in this report is not feasible anymore as the microwaves will heat the carbon steel. A still columnof stainless steel or a copper coating on the carbon steel are needed to evade this effect. To power themicrowave a cable of 8000 Volts needs to be added to the plant. These high voltages impose a newrisk to the plant as well, as there were no high voltage operations present before. Microwave unitsthemselves are also an additional risk as, when they are displaced, can cause severe burning into theskin. That way not only the skin is burnt but it will penetrate the skin and burn internally as well.

Moreover, an economic evaluation has been done. By adding microwave heating in the column thetotal CAPEX will increase. A rough cost estimation is provided by Dr Guido Sturm. A 6 kW microwaveunit costs around € 20,000, which scales more or less linearly. From Aspen Hysys the energy require-ment is calculated for a conventional unit. The figure found there is 141 kW for heating. Therefore aninvestment of around € 470,000 is needed for the energy requirement leading from the conventionalprocess. Contact with the French company Sairem was also made. They are currently investigatingthe use of microwave heated still columns. Their cost estimation is around € 550,000 for the internalsof such a column. The column itself will cost € 147,850 if it is made from stainless steel (SS316). Thisis a significant rise in capital expenses, as the initial capital expenses, as will be calculated in chapter 5are almost 10 times less. The weight of one 6 kW microwave unit is around 15 kg, so the total weightof a column with this duty will be 352.5 kg which is in the same ballpark as a gas fire heater.

Using microwave heating an efficiency of 80% can be expected. If the system stays unaltered andthe energy demands are more or less and a cost of € 0.1 per kWh is used the total yearly cost ofreboiling with microwave technology is € 264,278. This is almost € 100,000 more then a gas firedheater.

Dr. Guido Sturm also mentioned that microwave heating is only beneficial when a stream needs toa lot of heating. Regarding this system, due to good heat integration, the inlet stream in the columnalready is 170 °C. The additional 30 °C needed for distillation are presumably not enough to favormicrowave heating.

Considering all these additional costs and no guarantee that the reboiler can be taken out of thesystem it is decided not to pursue this technology any further. The investment is 10 times higher thena conventional still column and in OPEX no savings can be expected either. The presence of naturalgas at the platform makes a gas fired reboiler a better substitute for heating in the still column.

3.2.3. Alternative 2: Process scheme with pervaporation membranes andsemi lean injection

In this case, figure 3.10 shows a unit where the regeneration will be carried out with pervaporationmembranes.

Pervaporation membranesWith the use of only pervaporation membranes, the whole reboiler and still column may be replaced,with the consequent reduction of size and weight. Also the benefit of only having one piece of equip-ment to maintain is to be considered. However, it needs vacuum operation to improve the performanceof this technology for reaching the purity required (99.2% wt TEG). It will be created by condensationin the heat exchangers E201 as shown in figure 3.10 plus a vacuum pump. Moreover, an extra heateris needed to achieve the proper temperature of operation. However, to reach the purity described bythe water specifications a large amount of membranes modules are needed which can lead to largeand heavy equipment. That is the reason to consider a combination with a stripper column, too.

Furthermore, it should be mentioned that increasing the temperature till the required 150°C beforethe flash unit will lead to a reduction of water content in the liquid that will be sent to the membraneunit. However, this could not be done due to the high losses over the limits (around 0.08 kg/h TEG inthe vapour flash stream) in TEG encountered in the flash unit. Thus, the heating of the liquid streamis done after flash without creating vapour in that stream (0.004 vapour fraction) which will lower theeffectivness of the pervaporation membrane unit. It has been decided to follow with the design shownin 3.10.


Figure 3.10: Process scheme with pervaporation membranes (yellow box)

For a specific organic mixture (in this case TEG with water) one has to test to determine selectivityand fluxes during the process of dehydration, because the binding force of TEG to water is high, sofluxes will be lower compared to some other organics e.g. ethanol or IPA. In addition, it is moredifficult to dehydrate to such low water concentrations. Then a preliminary study of different types ofmembranes was carried out to find out these fluxes on basis of the conventional process outlet vapourstream from the flash.

First of all, apart from company claims, a paper was found which states that with commercial silicamembrane modules of the company Pervatech, if a feed of 0.054 wt water, 0.936 wt TEG and 0.005wt Toluene and 0.005 wt Hexane at 150 °C, a 99.99+% wt of water purity in the permeate can beachieved, at an average flux of 0.255 kg/m ·h [41].

In addition, an experiment performed to determine the water flux of a zeolite membrane modulefrom Mitsui USA was tested at 100 °C with a TEG mixture containing 5% wt water resulting in 0.13kg/m ·h as permeate.

Other sources say that 95% wt water purity can be achieved with NaA zeolite membranes exhibitinghigh separation performance and fluxes of 0.5 kg/m ·h for 5% wt feed water content at 120 °C. [42]

Also, a realistic research with improved membranes such as Sulfonated Poly-ether-ether Ketone(SPEEK) was carried, resulting in only 98% of water purity the permeate side with 5% wt water contentin the feed at 32 °C and flux of 0.2 kg/m ·h as depicted in Huang et al (2002) [43].

In other words, in order to estimate the area required for a complete separation we carried thisanalysis. It means roughly, avoiding pressure drops, no TEG losses in permeate, constant flux, 100%water permeation and no membrane size limitation, that if our stream of 1657 kg/h (0.0033 wt others,


0.912 wt TEG and 0.0847 wt water, see figure 3.11) from the flash is fed to a membrane unit we willobtain the results shown in table 3.3 and explained with two examples below.

Figure 3.11: Schematic representation of pervaporation membrane unit with inflow of 1657 kg/hcoming from liquid stream of flash unit.

• Example calculation for silica membranes:All water in feed goes into permeate1657 · 0.0847 = 140.35 kg/h, representing the 0.9999+ wt water in that stream, because this isthe maximum for this membrane.Therefore, 1657 - 140.35 = 1516.65 kg/h of TEG plus other compounds in retentate. All TEG infeed goes to retentate,1657 · 0.912 = 1511.18 kg/h, representing the 1511.18 / 1516.65 = 0.996 wt TEG and 0.004 wtof others in that stream.Hence, if the average flux of permeate is 0.255 kg/m ·h, we need 140.35 / 0.255 = 550 m ofmembrane.

• Example calculation for SPEEK membranes:All water in feed goes into permeate1657 · 0.084 = 140.35 kg/h, representing the 0.98 wt water in that stream, because that is themaximum for this membrane. It means that the total permeate flow is 140.35/0.98=143.21 kg/h,where 143.21 - 140.35 = 2.86 kg/h are other compounds except from TEG.Therefore, if in the feed there were 1657 · 0.0033 = 5.47 kg/h of others, 5.47 - 2.86 = 2.61 kg/hgo to retentate. Hence, if all TEG in feed goes to retentate,1657 · 0.912 = 1511.18 kg/h plus 2.61 kg/h results into 1513.79 kg/h of TEG plus other com-pounds in permeate, representing the 1511.18/1513.79= 0.998 wt TEG and 0.002 wt of othersin that stream.Finally, if the average flux of permeate is 0.2 kg/m ·h, we need 143.21 / 0.2 = 716 m of mem-brane.

Following the same reasoning, the results shown in table 3.3 were calculated, which in all cases is


more than the minimum required in the design case.

Table 3.3: Results of membrane area estimation

Membrane Temperature TEG in retentate water in permeate Areatype °C wt wt mSilica 130-150 0.996 0.999 562Zeolite 92-100 0.996 0.999 1080

NaA Zeolite 120 1.00 0.950 295SPEEK 30-70 0.998 0.980 716

It is observed that nowadays there is a lot of research on new membranes and that most of themfulfill the requirements for our dehydration purpose. However, there are not many supplier companies.Examples are Sulzer Chemtech Membrane Systems, based in Heinitz, Germany; and Pervatech BV ofEnter, The Netherlands, allowing a wide range of different temperatures, modules and flows.

Furthermore, although the major component in the over head vent is water stream, as shown, thisstream may contain organic compounds, including aromatic and non-aromatic organic vapours, suchas BTEX. The emissions of them are now classified as Hazardous Air Pollutants (HAPs), and are subjectto regulations which can be better handled by these membranes.

This is, therefore, a simple and reliable method to reduce or eliminate the release of these compo-nents, basically caused by the hydrophilic membranes which in one step both regenerate the solventand capture any hazardous components. Despite efforts, a cost-effective regeneration technology thattruly minimizes or eliminates HAP emissions has not yet been developed.

To finish, also a comparison of the energy consumption based on the heat requirement for evap-oration for the removal of 1 kg water from feed mixtures can be seen in the following figure 3.12,extracted from Huang et al (2002) [43].

It is clear in figure 3.12 that the advantage of applying pervaporation for dehydration of Glycolbecomes significant when the water content in the feed is significantly low. It should also be pointedout that this simple comparison was based only on the theoretical energy consumption at a constantpressure. Many other factors such as cooling of distillation, thermodynamic heat effectiveness, andcapital cost are not considered, all of which are important for the economic evaluation of these twoseparation technologies.

To maintain more realism in the design, Pervatech membranes were selected for further consider-ations. In the following study, a commercial Pervatech module PVM-080 SS 316 37×4-tube (120cm)with 3,7 m² membrane surface was used with these assumptions and characteristics[44] [45] [46].In the following images 3.13 and 3.14, a commercial Pervatech module is presented to get an overallimpression of the module we are using. In our case, instead of 7 elements of 4 channels each, we willused 37 elements of 4 channels each.

• Membrane element characteristics:

– Size: 1200 x 25 mm (LxD), effective area 0,10 m² (standard). Each element has 4 channelswith 7 mm inside diameter.

– Membrane type: Hybrid silica hydrophilic membrane.

– Substrate material: α-Al2O3.

– Intermediate layer: Gamma alumina.

– Top layer: Hybrid Silica coated on inside of the support tube.

– Pore Size: 0.3–0.5 nm.

• Limits of membrane:

– Temperature: limit max. 150 °C.

– Pressure: limit max. 50 bar.


Figure 3.12: Theoretical comparison of the energy consumption of pervaporation against distillation.Energy consumption (P) based on the heat requirement for evaporation for the removal of 1 kg water

from feed mixtures using 𝑃 = ∆𝐻 + ((1/𝑌 ) − 1) · ∆𝐻 where ∆H and ∆H represent theevaporation heat (kcal/kg) of water and Ethylene Glycol, respectively.

– pH: 2-8.5.

• Limits of operation:

– Maximal allowable working pressure 20 bar at 175 °C.

– Minimum design material temperate -20 °C at 20 bar.

– Vacuum: Level of vacuum depends on the application.

– Feed pump capacity: Linear velocity of the feed to be high enough to guarantee turbu-lent flow inside the tubes (Re ≥19000), this to prevent concentration polarization and limitfouling.

• Assumptions:

– 3.7 m of membrane/module (37 elements).

– TEG composition of 0.9895 wt in retentate, because it is needed for the semi-lean TEG splitstrategy.

– Water composition of 1.0000 wt in permeate (only water permeates).

– Temperature: 150°C.


Figure 3.13: Front view of PVM-094 SS 316 7×4-tube (120cm).

Figure 3.14: Side view of PVM-094 SS 316 7×4-tube (120cm).

– Pressure: 3 bar inlet feed, 20 mbar in permeate side and 1.5 bar retentate side.

– Permeate flux 0.255 kg/m ·h from the sensitivity analysis over a range between 120°C-150°C explained below 3.15.The reason to do is analysis is helping to decide the optimum temperature conditions of ourmembrane system. Therefore, it was tested the temperature effect versus different watercompositions for different temperatures which are presented in the following figure 3.15.

Due to the fact that the flux depends on the water content along the length of the membranebecause the chemical potential changes with water concentration in the TEG, a logarithmic average ofthe inlet value of water and the outlet was taken into account at 8.5% wt of water at the inlet and0.7% wt of water at the outlet. Hence, taking into account the assumptions mentioned, it led to theresults in table 3.4. One example of calculation has been provided below.


Figure 3.15: Feed water concentration against water flux in permeate for Ethylene Glycol- watermixtures [41]. In red is represented extrapolated data.

• Example of calculation of number of modules estimation:At 150 °C, the inflow for the membrane module is 1657 kg/h (0.0033 wt others, 0.912 wt TEGand 0.0847 wt water), this is take from Aspen Hysys. For achieving the purity required aftermembrane module (98.95% wt TEG) we follow:

All TEG goes to the retentate 1657 · 0.912 = 1511.18 kg/h of TEG, representing 0.9895 wt ofthat stream. Therefore, the total flow of retentate is 1511.18 / 0.9895 = 1527.22 kg/h.Hence, 1527.22 - 1511.18 = 16.04 kg of water plus other compounds. All other compounds goto the retentate too, due to high water selectivity of the membrane, 1657·0.0033 = 5.47 kg/hof other compounds(BTEX etc.). 16.04 - 5.47 = 10.57 kg/h of water goes into the retentate,representing 10.57/1527.22 = 0.0069 wt water purity in that stream.If 1657·0.0847 = 140.35 kg/h of water is fed, 140.35 - 10.57 = 129.8 kg/h is in the permeatewith 1.00 wt water purity.

At the entrance of the module, the water content in TEG is 0.085 wt, which represents a fluxof 0.612 kg/m ·h, while at the exit of the module the water content is the required 0.007 wtof water in TEG, which gives a flux of 0.075 kg/m ·h. Therefore, doing an logarithmic average


(0.612-0.075)/ln(0.612/0.075) = 0.255 kg/m ·h.Finally, if the permeate flow is calculated to be 129.8 kg/h, 129.8 / 0.255 = 509 m is needed. Ifevery module gives 3.7 m of effective membrane, around 509 / 3.7 = 138 modules are estimated.

Table 3.4: Results of number of modules estimation with PVM-080 SS 316 37×4-tube

Temp. Flux Retent. TEG Water Others Perm. Water Area Modules°C kg/m ·h kg/h wt wt wt kg/h wt m Nr150 0.255 1527.22 0.9895 0.0069 0.0036 129.8 1.00 509 138140 0.206 1527.22 0.9895 0.0069 0.0036 129.8 1.00 629 170130 0.255 1527.22 0.9895 0.0069 0.0036 129.8 1.00 828 224120 0.255 1527.22 0.9895 0.0069 0.0036 129.8 1.00 1350 365

To conclude with the temperature selection sensitivity analysis, it was decided to follow with 150°C,because it is the maximum allowed temperature for such a module as well as it gives the minimumnumber of modules. Furthermore, this temperature will be achieve thanks to a heater before thepervaporation module and not before the flash for the already mentioned high TEG losses in the flashat 150°C.

It is also very instructive and valuable to follow a sensitivity analysis about the maximum puritythat can be achieved with these membranes modules at 150°C if the semi lean split technique isneglected. Hence, taking into account the previous considerations and way of calculate the purity, theresults shown below were obtained for an inlet feed of 1657 kg/h (0.0033 wt others, 0.912 wt TEGand 0.0847 wt water, see figure 3.11) and a flux of 0.255 kg/m ·h .

Table 3.5: Results of TEG purity estimation in retentate with PVM-080 SS 316 37×4-tube

Retentate TEG Water Others Permeate Water Area Moduleskg/h wt wt wt kg/h wt m nr1557.9 0.9700 0.02649 0.00351 99.1 1.00 389 1051542.0 0.9800 0.01645 0.00355 115.0 1.00 451 1221527.2 0.9895 0.00692 0.00358 129.8 1.00 509 1381523.4 0.9920 0.00441 0.00359 133.6 1.00 524 1421516.7 0.9964 0.00000 0.00361 140.3 1.00 550 149

In table 3.5 it can be observed how the TEG purity increases as the membrane area increases andtherefore the number of modules, due to an increment in permeate flow. Three important values ofthe study should be noticed:

The first one is 98.95% wt TEG purity, which would be the value that allows the removal of thestill column, resulting in only one unit where a stripper increases the purity further from 98.95% till99.2%. This scheme is discarded however as TEG losses in the stripper column will be higher than thespecified limit, as shown in the proposed scheme 3.10.

Secondly, 523 m representing 142 modules would be the theoretical value needed to directlyachieve the minimum purity required for the process (99.2 %wt of TEG), with the removal of the stillcolumn and stripper too.

Finally, with 149 modules would achieve the maximum of 99.64% wt TEG purity with only perva-poration modules, which is above the minimum.

However, as conservative criteria are always more intelligent in design-wise thinking it is decidednot to go for the maximum purity, so the 98.95 %wt purity of TEG as the outlet stream unit is selected.The rest of the water needs to be taken out using a still and stripping column.

To check if the process can still be improvised with the lean TEG flow at theoretical minimum,another strategy was studied, called semi-lean TEG split flow.


Here, a part (50%) of incompletely regenerated TEG (98.95% wt TEG) exiting the Pervaporationis fed back to the contactor in the middle (above 4 stage).The choice of this flow and the stage inthe contactor to which it is sent is completely arbitrary. To maintain the total flow to contactor at thetheoretical minimum, the lean TEG flow is also reduced accordingly. Furthermore, these flows havenot been studied by splitting them to different contactor stages. This is based on the fact that we arerestricting ourselves to the theoretical minimum flow based on the findings of study of TEG split flowstudy done earlier in section 3.2.1.

It was observed that by using the above strategy, the stripping gas to the regeneration sectioncan be reduced by up to 20% of the conventional process without affecting the quality of lean TEGregenerated. The remaining 80% can be sent to overhead treatment or used somewhere else. Byreducing the flow to 50% after the Pervaporation membranes, the still column and surge vessel sizecan be reduced. The power requirement for the booster pump and the high pressure injection pumpwould also reduce in this case. But, in order to pump the 98.95% wt TEG to the contactor, an additionalhigh pressure pump would then be required. So to conclude with, this suggestion is added into thefinal different proposals shown below.

3.2.4. Alternative 3: Process scheme with hybrid systemThe third option considered is a combination of previous schemes with some little changes such as theincorporation of one heat exchange and a pump, resulting in figure 3.16 shown below.

Figure 3.16: Process scheme with hybrid system (turbocharge plus semi-lean split injection andpervaporation module (yellow boxes))

A pervaporation unit can be added to the still column heated with a gas fired reboiler. Pervaporation

3.3. Selection of the optimized process scheme 39

membranes can reduce the size of that still column as well as the reboiler, as they will separate themajority of the water (until reaching a purity of 98.98% wt TEG) from TEG and therefore reduce theweight of the unit. Also, it will reduce the emissions of BTEX and HAP gases. However, a pump(P201) must be added between these two pieces of equipment to overcome the head loss betweenpervaporation membranes and the still column as well as the pipes. Therefore, there will be two extrasubunits to maintain.

It should be mentioned that it was decided to firstly set the pervaporation membranes before thestill column due to the fact that these membrane modules work better with higher water content in thefeed. Thus, a stripping column before will reduce the percentage of water, avoiding a good performanceof the hybrid unit. Furthermore, as mentioned before, the pervaporation unit will be connected to thevacuum pump P-203 and also a heat exchanger E-204 is added to reach 150 °C before this unit. It wasdecided not to connect the still column to the vacuum pump P-203, because it was enough to add astripping column in which 20% of the vapour outlet stream from flash (V201) is used as stripping gasand a still column operating at atmospheric pressure to achieve the needed 99.2% wt TEG purity.

Semi-lean TEG will be taken out of the outlet stream of the membrane modules unit, representing50% of the flow, and injected halfway the absorption column. This will add a new injection pump(P-103) before the column. Also a turbocharger pressurizing both streams is added to the system tocut down on size of that pump.

3.3. Selection of the optimized process schemeIn conclusion, after having looked deeply into these three schemes, it was decided to go further withthe hybrid process system for the optimization study.

This is being proposed primarily because it would give us an opportunity to explore most of thenew technologies while reaching the high purity required in an optimized way.

Also, the benefits of all assumptions paint a very idealistic picture as far as the optimization inCAPEX, OPEX and weight is concerned. Although exact benefits of this proposal will be quantified inthe following sections of the project, verifying or denying its final feasibility.

4Hybrid Process

As was done in chapter 2 the total process will be walked through, describing it step by step. This timehowever the newly proposed hybrid system from chapter 3 are added. The new hybrid system will besized and designed. Also some comments and schemes about process control are added.

4.1. Process descriptionA detailed description of the process is given below. To start with, the wet gas is fed to the contactor(C-101), where it is contacted with lean TEG of 99.2% wt and semi-lean TEG of 98.95% wt in a columnwith a total of 6 packed stages to dehydrate the incoming gas below the outlet gas specificationsmentioned in earlier parts. The flow of lean TEG is the lower conservative estimate, below which it isnot realistically possible to achieve the specifications even if such a separation is shown to be possiblein Aspen Hysys. More details about this are given in section 3.2.4.

The energy of water-rich TEG leaving from C-101 at an approximate pressure of 156 bar is utilizedto drive a Turbocharger (P-101), thereby reducing the pressure of the rich TEG stream to 4.5 bar. Thissame energy is used by P-101 to increase the pressure of the incoming lean TEG and semi-lean TEGto 78 and 77.5 bar (considering 50% of the energy can be transferred between the streams using theTurbocharger).

Thereafter, the rich TEG-stream is preheated to 36°C by heat exchange with the exhaust gasesfrom the still column (C-201) top. Before sending these to the flash vessel, it is again heated in theGlycol-Glycol preheater (E-201) to 38 °C.

The Flash vessel(V-201) is operated at 4.5 bar. Here, a fraction of dissolved gases is separatedfrom the rich TEG stream. A fraction of 0.2 of these gases are further used for stripping in the reboiler(V-202) and C-201.

The liquid stream from V-201 is passed through Filter (S-201 A/B) to remove any suspended solidimpurities. Thereafter it is heated in the Glycol-Glycol Heater (E-202) to 107 °C and again upto 150°Cby Pervaporation Heater (E-204) using steam before it enters the Pervaporation membrane unit (S-202). The high temperature enhances the separation in the Pervaporation membranes. Here, usingchemical potential as the driving force, the water from the TEG stream is removed. To further enhancethe transfer, vacuum of 20 mbar is employed using a vacuum pump (P203). The outlet stream fromS-202 has 98.95% wt of TEG. To further increase the concentration from 98.95% wt to 99.1% wt, thisstream is sent to C-201 via Intermediate pumps (P-201 A/B). 50% of the outgoing liquid from S-202is sent back to the 4 stage of C-101 first via the second compartment of P-101 where its pressure israised to 77.5 bar and then via Semi-lean Injection Pump P-103A/B which raises its pressure to 156.5bar.

The TEG stream is stripped off the water and dissolved gas content in C-201. Exhaust gases fromC-201 are sent to overhead treatment. The remaining stream then passes through the inbuilt strippercolumn in the reboiler where its concentration is finally increased to 99.2% wt using 20% of the exhaust

41

42 4. Hybrid Process

gases from V-201 in the still column.

The hot lean-TEG obtained this way is sent to the surge vessel (V-203) and from there it is pumpedback via the booster pump (P-202 A/B) to the contactor section. On its way to the contactor section,it is cooled by E-202, E-201 and Sea water cooler E-203 to a final temperature of 34 °C

From E-203, the lean TEG is sent to P-101, where its pressure is increased from 1.5 bar to 78 bar.The pressure is further raised to 156.5 bar using High Pressure Pump (P-102 A/B) through which thelean TEG is finally sent back to C-101.

4.2. Material and energy balanceThe details of steps taken to model the plant in Aspen have been discussed in section 3.2.4. It is tobe noted that unlike the conventional process, it was possible to simulate using 99.2% wt TEG for thehybrid process.

Accordingly, three cases of mass balances were simulated in Aspen Hysys namely: Design Case,Turndown case and Max. flow case (120% gas flow). The Max. flow case is only being considered forsensitivity analysis.The sizing of the equipment will be based on the design flow case. All three casesare attached in Appendices I,J & K.

The Tables 4.1 and 4.2 summarizes the Mass and Energy balance of the Hybrid system for theDesign Flow case as obtained from simulations in Aspen Hysys. The component flow of water in theDry Gas is 6.7 kg/hr which is well below the limit of 24 mg/Sm3 (or 8.5 kg/hr).

Table 4.1: Overall Mass Balance for the Hybrid Design Case as obtained from Aspen Hysys

IN OUTStream No Energy Flow kJ/hr Stream No Energy Flow kJ/hr<102> 3.37 ∗ 10 <Dry Gas> 3.37 ∗ 10<Make Up> 24.11 <OVHD-1> 2.635

<OVHD> 3.231<Permeate> 130

Total 3.37 ∗ 10 3.37 ∗ 10

Table 4.2: Overall energy balance for the hybrid design case obtained from Aspen Hysys

IN OUTStream No Energy Flow kJ/hr Stream No Energy Flow kJ/hr<102> −1.47 · 10 <Dry Gas> −1.47 · 10<Make Up> −1.30 · 10 <OVHD-1> −1.23 · 10<P-102> 7333 <OVHD> −1.54 · 10<P-103> 7804 <E-203> −4.10 · 10<P-201> 97.38 <Permeate> −2.00 · 10<P-202> 164.1<V-203> 1.28 · 10<E-204> 2.27 · 10Total −1.47 · 10 −1.47 · 10

It was observed that in the case of turndown flow, all the gases from flash Vessel V-201 can besent to the overhead treatment. This makes the stripper column C-202 redundant in this case.


4.2.1. Energy demandsAll calculations are from Aspen Hysys. For the liquid turbocharger an energy recovery of 50 % isassumed as explained earlier.

Pumping

Table 4.3: Pump duties for the hybrid system

Type Head [mLc] Power [kW]P-102 A/B 692.9 2.04P-103 A/B 758.2 2.17P-201 A/B 7.9 0.027P-202 A/B 15.5 0.045P-203 A/B - 49

Heating

Table 4.4: Heating duties for the hybrid system

Name Type Power [kW]E204 Steam 61.31V202 Gas fired 35.56

Cooling

Table 4.5: Cooling duties for the hybrid system

Name Type Power [kW]E203 Sea water 11.37

4.3. Equipment sizingEquipment sizing has been done for all the pieces of equipment mentioned in figure 4.1 and 4.2.Also, as requested in the assignment for this course, a total equipment summary is added in the lastappendix, Appendix M.

All sizing has been done following the methods described in appendix A. All determined sizes arereported and tabulated. Sizes of similar kinds of equipment related the conventional process, if present,are also reported.

Furthermore, in this case also weight of each equipment is included in order to get a good compar-ison between conventional and hybryd units.

Vessel weight estimation have been preformed using the method described in Sieder et al[16].There, it is estimated that vessel weight depends on wall thickness of the shell, assuming the shell tobe evenly thick throughout the vessel with equation 2.1. It was decided also to take the pervaporationmembrane unit as a set of vessel modules.

Finally, heat exchanger weights are estimated using Aspen Hysys, whereas only motor weights havebeen used to estimate weight of pumps.


Figure4.1:

Thetotalflow

sheetofthe

contactorpart

ofthe

dehydrationsystem

.The

sizeofallthe

equipment

showninthe

figurehas

beencalculated.


Figure4.2:Thetotalflowsheetoftheregenerationpartthedehydrationsystem.Thesizeofalltheequipmentshowninthefigurehasbeencalculated.


Contactor (C-101)The height of the column in the hybrid system is assumed to be the same as the conventional. Thisis because the estimation has been done with trays which later on will be packed. There is significantspace between packing levels for an additional sparger so here there is no gain nor a loss in size.

Table 4.6: Size and weight comparison of both conventional and hybrid contactor column

Type Diameter [m] Height [m] Thickness [mm] Weight [kg]Conventional 2.04 12.19 190 143135Hybrid 2.04 12.19 190 143135

Vessel sizing (V201, V202 & V203)

Table 4.7: Vessel volumes

Vessel Type Volume Diameter Length Thickness Weight[m ] [m] [m] [mm] [kg]

Flash (V-201) Conventional 0.535 0.554 2.217 6 220Hybrid 0.313 0.46 1.85 6 154

Reboiler (V-202) Conventional 0.465 0.529 2.117 6 201Hybrid 0.132 0.347 1.392 6 87.6

Surge (V-203) Conventional 1.16 0.719 2.875 6 370Hybrid 0.342 0.476 1.906 6 164

Still column (C-201)

Table 4.8: Size and weight comparison of both conventional and hybrid still column

Type Diameter [m] Height [m] Thickness [mm] Weight [kg]Conventional 0.28 6.5 10 476Hybrid 0.145 6 13 310

Pervaporation membranes (S-202)For complete detailed calculations see appendix A. In this case, due to the uncertainty of size andweight, all the results have a 50% of security factor with following assumptions:

• The width and height of the unit were calculated, then multiplied by 1.5 to include space formaintenance and pipes and finally normalized into round dimensions.

• The length was taken equal as commercial Pervatech PVM-094 SS 316 7×4-tube module with 0,7m², because the membranes used inside for both are the same.

• The total size of the unit was calculated as rectangular set of 14x10 modules (WxH) of 1.402 mlength each, supposing there is no space limitation.

• For the weight, each module was considered a cylindrical vessel. Then a factor of 1.5 was includedfor accounting the weight of internal and membranes inside it.

The results for the pervaporation unit are displayed in the following tables 4.9 and 4.10

Pumps (P-101, P-102 A/B, P-103 A/B, P-201 A/B, P-202 A/B)In the hybrid system two new pumps are added and also a liquid turbocharger, or Glycol pump (P-101), is considered to be a pump. The first pump P-103 is added to injection the TEG straight from

4.4. Total weight 47

Table 4.9: Pervaporation membrane module size and weight

Module Type Flange Diameter Length Thickness Weight[m] [m] [m] [mm] [kg]

Pervap. memb. Hybrid 0.302 0.260 1.405 6 97

Table 4.10: Pervaporation membrane unit size and weight

Unit Type Modules Width Length Height Weight[Nr] [m] [m] [m] [kg]

Pervap. (S-202) Hybrid 138 7 1.405 5 13386

the pervaporation membranes. The other added pump, P-201, is used to transport the TEG from thepervaporation membranes to the still column. The duties of all the pumps are in table 4.11. The dutiesof P-102 & P-103 can be lowered however due to the addition of a liquid turbocharger. This will bediscussed further in 5.2.1.


Type Head [mLc] Power [kW] Weight [kg]P-102 A/B 692 2.04 88P-103 A/B 758.2 2.17 88P-201 A/B 7.9 0.027 22P-202 A/B 15.5 0.045 22P-203 A/B - 49 1666

4.4. Total weightThe total dead weight of the new hybrid system is 161,086 kg. This is calculated by adding all differentweights together. The conventional process had a total weight of 150,433 kg. This means the totalweight of the process increased with the introduction of the new innovations. The biggest differencescan be seen in the introduction of pervaporation membranes. The introduction of the membranes didnot cut down the weight of the still column enough to also cut down on the total weight of the systemeven though the weight of the reboiler is reduced with more then half. The split flow injection howeverhelped a great deal, it sized down all equipment after the split.

4.5. Safety, Health & EnvironmentIn the proposed hybrid system the species present are still the same as in the conventional processand therefore safety, health and environmentally aspects can be taken as equal as in the conventionalunit.

However, the only things that did change and can have an effect on the risk and hazard of thissystem are for instance the vacuum present with the pervaporation membranes unit. Also extra pumpshave been added such as injection pump or vacuum pump.

Finally, there are now two inlet points of TEG into the contactor column instead of only one, whichbrings an extra risk of leaking and malfunctioning of joints.

Furthermore, in the next subsection a HAZOP analysis will be conducted in order to select andevaluate problems that may represent future dangers to workers or pieces of equipment, or preventefficient operation.

4.5.1. Hazard and Operability study (HAZOP)For the hybrid system a HAZOP has been performed. For this study three points in the flow schemehave been chosen as mentioned below.


The first one is the TEG flow coming from the pervaporation membranes. The second point is thenatural gas outflow from the contactor. The last point is the TEG outflow from the surge. At these pointthe consequences and solutions for problems like too much flow or no flow have been considered. Theresults of the HAZOP can be found in appendix L.

Resulting the HAZOP, a few actions need to be taken. In the pipeline of point one, after thepervaporation membranes should be a concentration and a flow meter which need to be connected toan alarm. If there are inconsistencies in the values that these controls show then there is somethingwrong with either the membranes or the pumps. Also there should be a reverse flow prevention in thispipe. At point 2, after the contactor there should be a flow meter, for when the flow is too little big ortoo little either water is not removed from the gas or gas is leaving via an other route. This controllershould also be connected to an alarm. In order to prevent flow problems at point 3, after the surge, alevel controller has been put on the surge and has been connected to the valves controlling the in andoutflow of TEG from the entire system.

The meters that are only connected to an alarm have not been added to the control scheme inorder to keep the figure clear and readable.

4.6. Process control and instrumentationThe choices have been made following the plan found in the book of Seider, Seader, Lewin and Widagdo[16]. This book presents 9 steps to end up with a controlled system. The system has been split intotwo separate flow schemes, one which contains the contactor, and one that contains the regenerationsteps. In this case both schemes will be dealt with simultaneously. The resulting process controlschemes are shown in figure 4.3 and 4.4.

The entire process starts with the inflow of wet natural gas. The amount of natural gas coming inis not controlled for this unit but is set at the well head. The amount of TEG needed to dehydrate thenatural gas is dependent on the water content of the natural gas entering the system. The amount ofwater present in the natural gas inflow is measured by concentration controller CC-101. This controlleris connected to the valve that controls the inflow of TEG coming from the surge(CV-101). The secondTEG inflow, coming from the pervaporation membranes, is controlled with a ration controller (RC-101)connected to the previously mentioned stream via RV-101. The rich TEG flow from the contactor iscontrolled with a level controller(LC-101) in the contactor via valve LV-101. This is because there shouldbe a constant level of TEG present in the bottom of the contactor. The natural gas outflow from the topof the column is controlled with a pressure controller(PC-101) which will be set to a certain pressureand that way control the outflow via valve PV-101.

The rich TEG first goes to the flash (V-201). Here the gas outflow is controlled with pressurecontroller PC-201 with a valve on the outflow (PV-201). The liquid outflow is controlled with a levelcontroller (LC-201) via valve LV-201. To prevent build up of contaminants in the flash there is an extraliquid outflow, the drain, which will be manually controlled.

The TEG will now go through the pervaporation membranes to the still column. The gas outflowfrom the still column is controlled with pressure controller PC-202 via valve PV-202. The liquid TEG willgo to the reboiler and then the surge without passing another valve. The surge needs a liquid levelbetween certain values. Liquid controller LC-202 is in charge of this. When the level gets too low, valveLV-203 will open end lean TEG from storage will come in. If the level gets too high, LV-202 will openand TEG will flow to the storage tank.

The amount of water that is taken out of the TEG in the still column is primarily determined by theenergy input into the reboiler. There will be a temperature controller (TC-202) which will try to keepthe reboiler at a certain set point by increasing or decreasing the fuel gas going into the reboiler viavalve TV-202. The set point will be determined with the concentration controller CC-201. When theconcentration of water gets too high the temperature in the reboiler needs to be increased and viceversa.

From the surge the TEG will go through two heat exchangers and then a sea water cooler. Theamount of sea water passing through the cooler is controlled with temperature controller TC-201 whichis placed behind the cooler. The water flow is controlled with valve TV-201.

4.6. Process control and instrumentation 49

Figure4.3:Thetotalflowsheetwithcontrolsforthecontactorpartofthesystem.


Figure4.4:

Thetotalflow

sheetwithcontrols

forthe

regenerationpart

ofthe

system.

5Economic Analysis

In this chapter all investments for both the conventional as the hybrid system are estimated. Thesizes are taken from appendix A. First the total investment costs are estimated using Lang’s methodand secondly the OPEX is estimated. All economic reduction achieved by the new process are in thischapter.

5.1. CAPEXAll prices are estimated using the Prijzenboekje of the Dutch Association of Cost Engineers [47]. Exceptfrom C-101, P-101 & P-202. These are estimated using the Matche’s website [48]. All prices have beenadjusted to 2014 using CEPCI numbers. If a price was found in US dollars an exchange rate of 1.25euros per dollar was used to convert it [49]. Finally, a factor of 1.25 is used to transform this pricesfrom USA to EU displacement.

5.1.1. ConventionalVessels & columns

Table 5.1: CAPEX for all vessels and columns in the conventional process

Equipment Number Diameter (m) Length (m) Thickness (mm) Price (Euro)C-101 1 2.04 12.2 190 €1,160,000C-201 1 0.27 6.5 10 €68,738C-202 1 0.25 0.5 6 €27,236S-201 A/B 2 0.0254 - - €6,459V-201 1 0.55 2.22 6 €23,750V-202 1 0.53 2.12 6 €23,594V-203 1 0.72 2.88 6 €25,781

PumpsPrices of pumps were estimated with the Prijzenboekje [47].

Table 5.2: CAPEX for all pumps inside the conventional process

Equipment Number Capacity (m /h) Head mLc Max. Power (kW) Price (Euro)P-101 2 2.3 1370 13.4 €19,973P-202 A/B 2 2.7 20 0.155 €11,932

51

52 5. Economic Analysis

Heaters & CoolersPrices of heaters were estimated with the Prijzenboekje [47].

Table 5.3: CAPEX for all heaters & coolers inside the conventional process

Equipment Number Area (m ) Price (Euro)E-201 1 28.45 €35,017E-202 1 147 €89,489E-203 1 17.3 €33,720

Total costsThe total investment costs for equipment can be calculated now by adding all these prices. As thisis a fluid and gas plant a Lang factor for process equipment and installation of 5.93 is estimated[50].This gives a final investment of € 9,047,332. As mentioned by frames a conventional unit has a pricebetween 5-10 million euros, so this estimate seems to be accurate.

5.1.2. HybridVessels & ColumnsFor the calculation of a membrane module price, the following assumptions were take into account:

• The module is considered as a vessel of SS 316. Therefore with 0.26 m diameter, 1.402 m oflength and 6 mm thickness.

• The price of SS 316 is calculated by its weight (97 kg obtained in unit sizing, Chapter 4) followingMatche’s web page [48]. Then a factor of 1.5 of security is added to account the price of themembrane elements.

The results for the estimated price of one module are presented in the following table 5.4.

Table 5.4: CAPEX for a pervaporation membrane module

Equipment Number Diameter (m) Length (m) Thickness (mm) Price (Euro)PV module 138 0.26 1.402 6 €20,156

From contact with Pervatech, it was given that a module of 4 elements on 50 cm length with aweight of 10 kg costs about €5,000. Thus, having a module of around €20,000 is totally feasible. Theother vessels are estimated using the same methods as with the conventional process.

Table 5.5: CAPEX for all vessels and columns in the hybrid process

Equipment Number Dimension (m) Length (m) Thickness (mm) Price (Euro)C-101 1 D=2.04 12.2 190 €1,160,000C-201 1 D=0.145 6 13 €73,925C-202 1 D= 0.25 0.5 6 €27,236S-201 A/B 2 D=0.0254 - - €6,459S-202 1 W=7 and H=5 1.402 - €2,781,000V-201 1 D=0.46 1.85 6 €22,813V-202 1 D=0.35 1.39 6 €21,563V-203 1 D=0.48 1.91 6 €22,969

5.2. OPEX 53

PumpsPrices of pumps were estimated with the Prijzenboekje [47].

Table 5.6: CAPEX for all pumps inside the hybrid process

Equipment Number Capacity (m /h) Head mLc Max. Power (kW) Price (Euro)P-101 1 2.5/0.8/0.7 - - €12,813P-102 A/B 2 0.7 692 2.04 €25,625P-103 A/B 2 0.7 758 2.17 €25.625P-201 A/B 2 1.2 7.9 0.027 €13,229P-202 A/B 2 0.8 15.5 0.045 €13,229P-203 252.3 - 49 €28.750

Heaters & CoolersPrices of heaters were estimated with the Prijzenboekje [47].

Equipment Number Area (m ) Price (Euro)E-201 1 4.424 €33,720E-202 1 24.35 €35,017E-203 1 2.64 €27,236E-204 1 2.44 €27,236

5.1.3. Conclusions regarding CAPEXWhen all the prices for hybrid are added to each other and the Lang factor has been incorporated aprice of €25,845,566 arises for total ownership. This is almost three times higher as the conventionalprocess, which costs € 9,047,332. While all equipment is reduced in size and price the introductionof membranes is such a big investment that the end price is much higher. This observation is also donewith regard to the weight of the total unit.

5.2. OPEXAs this process only represents one step in a whole offshore process the OPEX is only calculatedregarding the pumping, heating, cooling and some remarks about maintenance will be done. It isexpected that only these factors are changed with the introduction of new technologies.

5.2.1. PumpingConventionalIn the conventional process two pumps are present, P-101 and P-202. With the specification given intable 5.7. These were taken from Aspen Hysys simulations.

Table 5.7: Specifications of both pumps in the conventional

Equipment Number Capacity (m /h) Head mLc Max. Power (kW) Price per year (€)P-101 1 2.3 1370 13.4 € 11,738P-202 A/B 2 2.7 20 0.155 € 135Total 3 - - 13.555 € 11,873

HybridAs pump P-202 is used to compensate the pressure drop in the system it is a vital and unchangeablepart of the process. P-101 however can be powered by using the pressure which is released from

54 5. Economic Analysis

the rich Glycol stream. The total operational costs, assuming a total cost of 10 ct €per kWh[36], is1.34 €per hour [37]. Assuming 24/7 operation the total costs per year of this pump will be € 11,738.Using calculation tools provided by Energy Recovery©a recovery of 70 % of energy can be achieved.This will result in a evenly large reduction of operational costs. So a reduction of € 8,216 on a yearlybasis can be achieved. Not only that, also a reduction of 9.38 kW is achieved at the pumping section.This leads to a reduction of approximately 79,866 kg CO which is released on a yearly basis[38]. Byadding a split injection system however the injection pumps change. An additional pump is neededbecause of the addition of an extra stream. An extra pump is also needed to transport the TEG fromthe pervaporation membranes to the still column. The power duties are displayed in Table 4.11. Thesecond injection pump makes it harder to have the same beneficial effects of the turbocharger as inthe conventional process as not one stream with more or less the same needs to be pressurized, buttwo streams with half the size. Contact has been made with Energy Recovery regarding this. Theymentioned that it is possible to use the power released and transfer it to two separate streams, butit makes the system less efficient and harder to control. A maximum efficiency of 50% of recovery isassumed to use in calculations.


Type Head [mLc] Power [kW] Price per year [€]P-102 A/B 1426 2.040 € 1,787P-103 A/B 1647 2.168 € 1,899P-201 A/B 7.9 0.027 € 24P-202 A/B 15.5 0.045 € 39P-203 A/B - 49 € 42,924Total € 46,673

5.2.2. HeatingConventionalA large energy consumer in this process is the reboiler. From Aspen Hysys the energy requirement iscalculated. The figure found there is 241.35 kW for heating. Assuming an efficiency of 90% for a gasfired heater and a gas price of € 0.07 per kWh a total yearly cost of € 164,439 for natural is needed[36].This figure can drop however as the natural gas coming from the flash can be used as a ”free” sourceof natural gas.

Table 5.9: Heating duties for the conventional system

Name Type Power [kW] Price per year [€]V-202 Gas fired 241.35 €164,439

HybridIn the hybrid system heating is done at two places. Firstly before the pervaporation membranes andsecondly in the reboiler section. It is chosen, for weight limiting reasons, to use heat exchange withsteam before the pervaporation. The amount of steam needed is calculated via the total flux needed.A price of €25 per ton is assumed[51] [52]. The reboiler will still be heated using a gas fired heater.

Table 5.10: Heating duties for the hybrid system

Name Type Power [kW] Price per year [€]E-204 Steam 61.31 € 23,257V-202 Gas fired 35.56 € 37,595

5.2. OPEX 55

5.2.3. CoolingConventional

Table 5.11: Energy duties needed for cooling in conventional

Location Type Energy duty [kW] kg/h neededE-203 Sea water cooler -103.5 8,988 kg/h seawaterC-201 TEG condenser -49.85 -

The condenser is cooled using the rich TEG before flash. By using this heat integration the heatingduty of the reboiler is lowered and this cooling can be performed for free. For the cooling of the leanTEG before entering the absorption column sea water is used. As the process is done off shore thiswater can be gained for free as well. The water needed is calculated using the method as described inA.

Hybrid

Table 5.12: Energy duties needed for cooling in hybrid

Location Type Energy duty [kW] kg/h neededE203 Sea water cooler -84.5 978.3 kg/h seawaterC201 TEG condenser -40.36 -

5.2.4. Conclusion regarding OPEX

Table 5.13: Total operational expenses

Type Expenses per year [€]Conventional € 176,312Hybrid € 107,525

As shown in Table 5.13 the total expenses towards energy are reduced. Yearly almost € 70,000 issaved due to better energy use. The introduction of pervaporation membranes and the use of a splitflow has decreased the energy needed for the reboiler with 85%. Furthermore the introduction of aliquid turbocharger and the overall lower TEG inventory has decreased the total kWh per year needed forpumping of TEG with 70%. The addition of a vacuum pump at the pervaporation membranes howeverhas a relatively high duty in comparison with the other pumps of 49 kW needed. The introductionof these new innovation has a positive effect on OPEX and total energy consumption making this agreener alternative to the conventional process.

6Creativity & Group Process Methods

In the following chapter of the project, several strategies for improving the team’s development andcreativity have been carried out in order to facilitate the communication, coherence and connectionwithin the team as well as generation of new technological ideas. The results are shown below orderedby date. After this the project planning and creativity methods used are described.

6.1. Team division, process tools and resultsDuring the PPD course a Belbin Test was executed by each team member to identify their best own roleand behaviour in group work. As this is seen as a valid way to find the different skills of each member,the test is going to be used to divide and allocate responsibilities.

In such way, we have defined Agnes as the Coordinator, the person in charge of delegation of workand selection other member of the group by talent. Therefore, it also is decided that she will be ourmain Planner and will decide who does which tasks. On the other hand, the other team membersneed to mind that she does not off load her own share of the work as well. Secondly, Javier is anImplementor, which means he will prove himself to be a valuable and efficient worker. His organizedway of working can also be of great value for the rest of the team as he can help planning and comeup with a practical and effective ways of working. However, the rest of the group should mind thefact that he maybe has to put in more effort to adapt new ways of working, when a decision has beenturned around and his nervousness when you have to work under pressure. In third case, Ameya hasthe role of a Monitor Evaluator, which makes him a sober and strategic mind. Hence, when it comesto decision making, he can prove to be a valid asset. But, as the rest of the team may depend onhim about specific decisions, he makes himself sometimes over-responsible and only focuses in onetask. Finally, Toon is a Recourse Investigator, which means he easily makes contacts and exploresopportunities. This results in a valuable way of doing the communication for the group and towardsothers. He will also take up the role of the group Secretary and do most of the reporting. However, hemight make ‘silent’ decisions without asking others.

Apart from team members, we had the figure of Creativity Coach helpings us ignite our minds withcreative approach to reach the final goal. In cases of standstill creativity, we expect advice on how tocontinue and come up with new ideas or methods. Moreover, the Technical Supervisor would be theone with whom we would be in contact on regular basis, to guide us in case of technical doubts andlike a guiding lantern, bring us back to our path if we digress too much from the goal. Last, but notleast, from the principals, we would like to get necessary process details with full clarity on the projectexpectations. Also, we expect the principals to be approachable and open to queries, if any, in thecourse of project.

From the above, it was defined the group division for this project. Despite the fact that each one hadtheir own responsibilities and strengths, one should never forget that in engineering projects propercommunication is the key to avoid misunderstandings or vagueness. This can only be done if the

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58 6. Creativity & Group Process Methods

weaknesses of each member are known in the whole group, so everyone try to overcome his/her ownproblems with the help and support of the others. It must be taken into account also all the feedbackreceived from the people involved in the project, creating a ping-pong information chain where allinformation, advises and critics were considered. For those reasons, some activities were done asmentioned below:

• (27-04-2015) Creation of an online database: All the files and documents related to the projectwere shared with team members and supervisors. In this way, information was available foreveryone anytime.

• (27-04-2015) Creation of a calendar: Definition of task distribution according to team membersallocation, main milestones and tentative deadlines, in order to define a structured planning ofthe whole project.

• (27-04-2015) Creation central mail account: This was used as the main communication hub. Inthat way everyone could look back in previous contact with whomever and have always a clearview of what was going on.

• Everyday’s meeting in the morning: Revision of the calendar and project development, whathad been done, needed to be improved or changed. Below, it is shown a summary of the maindecisions taken in each week because of these meetings.

– Week 1 (from 27-05 to 01-05): After having the first meeting with the technical supervisorand with the creativity coach in this week, we defined the main points to be discussed in thekick-off meeting with Frames’ principals as well as the tools we were going to use for thegeneration of new alternatives of the process (See section 6.2 Creativity tools and results).

– Week 2 (from 04-05 to 08-05): Visiting our principals in Frames building situated in Alphenaan den Rijn resulted in a enriching and valuable experience. It gave us the opportunity toget to know each other and discuss several points that were unclear. For instance, the scopeof the project, the alternatives to be investigated and the conditions used as reference weredefined. In addition, two of the alternatives shown were criticized (Molecular sieves + TEGunit and Super X-packing) due to the fact that they do not meet the objectives. A tentativeplanning was also proposed and approved. (See section 6.3 Process planning).

– Week 3 (from 11-05 to 15-05): With all the feedback and the points clear we made a seriesof creativity activities in order to generate more alternatives apart from the ones Framesprincipals gave us. The result was the finding of three realistic technologies that can be usedin this unit, and that will be presented in the Basics of Design (BoD) meeting scheduled forweek 5. In this week 3, we also had a meeting with P. Hamersma, where some questionswere posed, clarifying that we need to be more specific and consistent in our selection ofalternatives, including quantitative descriptions and equipment functioning principles andfundamentals. In this way, knowing how the piece of equipment really works, we wouldunderstand how to improve it and why one alternative is more suitable than other. Hence,we started the (BoD) with all the input required.

– Week 4 (from 18-05 to 22-05): We still worked in the BoD and the design of the processin Aspen Plus, scheduled to be handed-in on 22nd May. We had a meeting with B. Damto discuss about the results of the creativity tools. It was pointed out that more imagesand tables would be used, because they are the best option to shown a list of alternatives,instead so much text. The BoD report was given to all implicates for review and feedback.

– Week 5 (from 25-05 to 29-05): In the BoD meeting, where all people involved in the projectwere present, the final 8 technological possibilities were shown. It was decided to followwith hybrid one, in which it would be used split injection, turbochargers and a combination ofstill column heated by microwaves and pervaporation membranes (See section 3 Innovationmap). It was also settle the conventional process that would work as benchmark as well asthe change into Aspen Hysys to simulate the process, because Aspen Plus does not fulfillsome requirements. Furthermore, some professors and specialists in microwave heatingand pervaporation membranes were contacted such as PhD. Guido Sturm.

6.1. Team division, process tools and results 59

– Week 6 (from 01-06 to 05-06): It was introduced an important change in the simulation.Now the feed of wet natural gas is saturated before entering the column, which will be theworst scenario possible for the unit. Then, the conventional process was finished. The sizeand price of the unit is decided as benchmark. The project follows as scheduled and notmore important changes are made.

– Week 7 (from 08-06 to 12-06): The company Sairem was contacted regarding microwavesgenerators and prices of them were obtained and incorporated to the unit.Also, Mr. Sturm gave us his advice about microwaves, stating that they are feasible inconcept, but no company has tried yet.

– Week 8 (from 15-06 to 19-06): On Monday the 15th June, the final draft report was sub-mitted to all the parts involved in the project in order to get feedback of it.Furthermore, an important change was introduced. Finally, all results led to bad perfor-mance as well as an increment of the unit price when microwaves are incorporated due tothe immaturity of this devices yet. Therefore, it was decided to erase them of the hybridproposed solution.Finally, Pervatech was asked to provide details of the membranes modules used in the design.

– Week 9 (from 22-06 to 26-06): The comments on the draft report were given and includedin the final report. It was submitted on Friday 26th.

• Meetings with creativity coach, technical supervisor, professors or experts: Discussion of maindoubts and problems as well as forecasts for the next steps.

– Dr. P. J. Hamersma, Technical supervisor: Thanks to the experience of the technical su-pervisor, we were able to go on with the project every time a problem arose, especially inthe selection of improvements for the conventional process. He pointed out that the bestway to overcome any problem is understanding ‘the chemistry’ behinds it. This advice wasfollowed in every piece of equipment in order to come up with new technologies that willimprove the performance of the unit. Moreover, he mentioned that every figure, graphor image should contribute with valuable information and should be followed by extensiveexplanatory description.

– Dr. B. Dam, Creativity coach: His contribution was very important in the generation of newideas. He provided us with another approach of the project where the technical rules werenot the most important aspect, implementing the creativity of new designs. Team division,progression and the roles of each member were followed by him with relevant feedbackabout our behaviour within the team.

– (18-05-2015) Ir. S. Groenendijk, Process Eng. at Fluor: He solved our doubts about theturndown case, ending in decreasing only 50% the amount TEG compared to the designcase, because less can create cavitation and the still column can start weeping. After con-sulting principals from Frames, it was decided to maintain only 33% of the TEG.

– (28-05-2015) Pr. A. Stankiewicz, Professor: As process intensification expert, he helpedus in the definition of our improved process, giving tips and boundaries such as realistictemperatures for microwave heating that could not be found in literature. He also proposeda radical new design based on rotating packed beds.

– (28-05-2015) J. James, PDeng: Mr. James shared with us his knowledge about Aspen andtips on the relationship between high pressure systems and the thermodynamic model usedin the simulation, resulting in different model for each piece of equipment that simulatesbetter the process.

– (29-05-2015) M. Radiou, R&D Eng at Sairem: Always ready to help regarding to microwavesystems, she gave us some useful information as well as prices for such devices.

– (9-06-2015) G. Sturm, PhD: As a PhD in P&E institute at TU Delft, he shared with us hismicrowave related thesis where we could find information about how this equipment worksintrinsically.

– (14-06-2015) Prof. Dr. Ir. Anton A. Kiss, R&D Eng at AkzoNobel: With his advise over thepervaporation membranes, we were able to complete the Aspen Hysys simulation.


Besides those activities, we do believe that productivity and efficiency can be enhanced if there isa relax atmosphere in the group. So, we also take into account the relationships between us:

• Weekly dinner: Taking advantage of our international team, we decided that everyone needs tohold a dinner with food of his/her own country, and it seems it is working perfectly.

• Card games: During breaks, we play different card games to chill out and rest from the projectitself, resulting in a better work environment.

6.2. Creativity tools and resultsThe following creativity techniques, whose description, date and results are shown below, were plannedand used in the course of this project.

• (08-05-2015) Brainstorming: We used this technique at the starting point of the conception stage.It requires a minimum of 4 people.

For using this technique, the participants were required to come up with a large number ofideas without inhibition. Seemingly wild and unexpected ideas were also considered equally.Thereafter, the ideas were grouped and an overview of all solutions was created. We startedwith a warming-up round about Norway, natural gas and Frames. Then, we continued withDehydration with TEG process. Brainstorming has the advantage of generating large amount ofideas, which are advantageous for in this project helping us in suggesting as many optimisationstrategies to reduce the CAPEX ,OPEX and weight of the TEG unit, which is the main goal of theproject. We realised that we have three groups of ideas: Environment and weather (cold, fjords,ice,...), technology (offshore, pipeline,energy,...) and company (oil, gas, money, future,...). Itshould mention that they also appeared bad ideas such as toxic, pollution, fire, old technology,...;meaning that this technology may still has the stereotype of petroleum industry.

• (12-05-2015) List of ideas and dream power: This approach was used after the Brainstorming.During some days, team members were asked to come up with 10 solutions or improvements tothe bottlenecks found in the project without taking into account the objectives of it and if they arefool. It was also stated that this should be done right before going to sleep, because specialistsclaim this can help to the generation of ideas.

The result was the creation and presentation of about 40 ideas, such as integration of absorptionand regeneration in one single column, using of supercritical solvents, pipelines with desiccant,using the outlet gas from flash as a motive fluid for vacuum ejector or condensers in every trayto remove the water, among others. Two of these ideas were selected for further study in theproject: Addition of a entrainer in the regeneration column and the combination of molecularsieves with a TEG dehydration unit.

• (12-05-2015) Mind map and visual thinking: This technique involves graphical representation ofideas, depicting how these ideas are related to each other. This technique can be used at differentstages of the project, but we employed it in the conception or the idea generation phase, gettinga graphically structured overview of thoughts or ideas and providing a thorough understandingof a equipment main functions and sub-functions.

In this technique, first all the members voted the 2 best ideas of each other, after they were askedto draw 2 of them without any explanation from his/her creator. Every aspect of each design wasexplained and discussed with the creator of the idea. This way, we realized what different pointsof view a single idea can have and how some of them are maybe good enough for ourselves inour mind but not in reality.

• (12-05-2015) 4x4x4: This is more a technique for improving decision making, connection, coher-ence and communication in the group. In this case, each member has to take 4 out of his/her10 ideas, then in pairs, both members has to select 4 out of the previous 8 (the chosen 4) andfinally, the whole group must choose 4 out of the las 8 (4 of each couple).

6.3. Process planning and results 61

Eventually, it came that among the last 4 selected ideas, 1 was of each member. The mostprobable reason for this can be that each of us strives for his/her own ideas, while also wesupport other choices, always maintaining the balance in the group.

• (15-05-2015) Collage: This method is the way to view your problem in a total overview of whatyou know about it. By printing out images and facts about the problem, new connections, previ-ously unseen, can arise. This was the last approach used in the basic of design and generationof ideas. In our case the problem of size is a nice one to try to observe in this manner. By look-ing for connection between different process steps, maybe a scale down or a potential differentconnection which we have not seen before could be found.The team members needed to collect data and 5 images about the problem we are strugglingwith. The process of choosing images should be totally random and nothing should be hold backbecause it does not seem to fit in the scope of your problem. Everything was hang upon the wallin our office and after the group started arranging everything in one way or another to look fornew plans or methods to implement in the system.

6.3. Process planning and results6.3.1. Overall planning and deadlinesThe project was divided in three stages: The preparation stage, the concept stage and the feasibilityand development stage. Each of which were ended with a presentation. All details can be seen infigure 6.1.

Figure 6.1: Planning used during the project. There are three main phases: Preparation stage(leftorange line), conceptual stage (middle orange line) and feasibility & development stage (right orange

line).

Preparation stageThe main focus is laid upon the question if this project is worth pursuing. Initial goals and deadlineswere stated and planned as shown in Figure 7.1. The first alternatives would be briefly researched to


get a preliminary feeling about them all. The preparation stage ended on the 7th of May, and the kickoff meeting was conducted on that day, too.

Concept stageDuring the concept stage the work revolved around the process itself, what are customer requirementsand how to get there. The existing process was worked out to provide a benchmark for later improve-ments. All different improvements suggested before were divided between the team and everyone dida more extensive research into them. The first Aspen Plus simulation was made to provide a bench-mark for calculation of the impact of the different technological improvements in the feasibility stage.Furthermore all the data needed to calculate later on was searched and inventoried for later use. Thisphase would lead to a BoD report which will be finished 22nd May, whereas, on 27 May the report waspresented.

Feasibility & Development stageLast stage of the project. The team worked on implementing the new technologies selected and seeingthe impact they would have upon the process. Financial calculation was done to estimate the CAPEXand OPEX of the new and old system to see demonstrate the way improvements helped. Weightestimates needed to be made to compare them as well. Also, the final report was produced in thisstage, ending on 30th June with the final presentation.

6.3.2. Work divisionTo make better use of time, effort and our capabilities, every team member had been allocated differenttasks and responsibilities considering team division (See section 6.1 Team division, process tools andresults). As the focus lied upon 4 technologies every team member was chosen to be expert of thatarea. Agnes would focus on microwave heating and coordination of all the tasks. Ameya on TEG splitinjection system and Aspen simulation,too. In addition, Javier was upon pervaporation models and theorganization and planning of the project. Finally, Toon would research liquid turbochargers and wouldbe in charge of the reporting and communication.

Furthermore every team member gets an part of the assignment for which he or she will be heldresponsible. If the team member feels that it will not be done on time it will communicated with therest of the team and he or she can offload some work to someone with less. Agnes is responsible forwriting the parts concerning the safety of the process. Ameya will be working on the Aspen Plus withhelp of the rest of the group, but he will be the one having the overview and is responsible to haveit finished on time. Javier is responsible for the financial and creative part of the operation.Toon is incharge of making the report and the planning of all the different tasks. Toon and Ameya would alsolook into the equipment sizing, CAPEX and OPEX research.

7Conclusions & Recommendations

When taking in account all the information given throughout the report, it can be concluded that theintroduction of semi-lean TEG injection, pervaporation membranes modules and liquid turbochargersleads to a lot of changes in CAPEX and OPEX, while the weight of the total new unit does not changetoo much, but remaining within the same range. This can however be due to error margins of thecalculations done.

First of all, by introducing the specific combination of techniques, the CAPEX has doubled. All ex-isting equipment from the conventional process, except the absorption column, have been reduced.However, the investment costs for the special kind of membranes used for pervaporation is so largethat the benefits from using smaller equipment are counteracted. So, this separation technology maybecome interesting in terms of CAPEX if in coming years it matures, achieving more effective mem-brane area per module with the same water selectivity, leading to higher permeate fluxes. Then thisinvestment price will drop drastically. It should be pointed out that the price estimation for pervapora-tion membrane modules a very crude one, due to the lack of reliable information and the scale of theproject. For instance, Pervatech themselves did not know the possible prices of this proposed largepervaporation system. Hence, because of this uncertainty, the margin of error in cost estimation ofthe hybrid process is much larger than that of the conventional.

On the other hand, the OPEX has been lowered a lot in comparison to the conventional system.A total saving of almost € 70,000 per year has been achieved. This was solely done by savings inenergy, which makes the hybrid system a more energy efficient and greener alternative compared tothe conventional process.

Furthermore, as mentioned, the weight of the total unit has increased from 150 tons for the conven-tional dehydration system to 160 for the hybrid system. But as mentioned before, this approximately10,000 kilograms gain is so low that it lies within the calculation error.

To sum up, the introduction of pervaporation membranes has decreased the total energy consump-tion, but it increased the total capital expenses, leading to a rate of return for all the changes introducedof around 200 years, which is too long for this kind of industry. As stated, if the surface area of themembranes increases and so the total capital expenses decreases, then membranes can be a goodoption for improving TEG dehydration. However, as these membranes are currently too expensive, itis not advisable to add them to the process now.

Liquid turbochargers however have decreased 70% of the power needed for TEG transport. Ac-cordingly, this decrease is a feasible help in energy demand reduction, as for TEG pumps the energyconsumption in the conventional system is really high. For this reason, they are already being deployedin process industry. The recommendation is to add these TEG turbochargers to newly developed pro-cesses and to implement them in already existing plants since this is also possible.

Finally, the injection of semi-lean TEG into the absorption column has sized down the reboiler andsurge vessel with 30% even when it has not been optimized yet. Thus, room for improvement areanalyzing different injection points in the column, purity of semi-lean TEG and flow of split optimizing

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64 7. Conclusions & Recommendations

the gain of this setting. However, because the pervaporation membranes are not present in the con-ventional process, there is not an easy way of getting semi-lean TEG from the regeneration unit. Forinstance, the still column needs to have an additional middle outlet altering the design of the distilla-tion equipment. For this purpose, a distillation column can be considered first to achieve the necessarysemi-lean TEG purity, sending afterwards the stream to other possible technologies such as molecularsieves where to reach the total lean purity required (99.2% in our Hybrid case). To find out if this isbeneficial will requires a completely new research project.

List of Symbols

ΔP Pressure rise [kPa]

𝜌 Density of vapor [kg/m ]

𝜌 Density [kg/m ]

𝜌 Density liquid [kg/m ]

𝜏 residence time [hr]

A Surface [m ]

A Downcomer are [m ]

A Tower inside cross-sectional area [m ]

D external vessel diameter [inches]

D outside diameter [inches]

D Diameter of the tank [m]

E Fractional weld efficiency

E modulus of elasticity [psi]

F Liquid flowrate [kg/hr]

f*U Fraction of the vapor flooding velocity [m/s]

G Mass flow rate of gas [kg/s]

h Height [m]

L Length [m]

L vessel length [m]

L tangent-to-tangent height of the column[inches]

LMTD Log mean temperature difference [C]

P internal design pressure [psig]

P internal design pressure [psig]

q Heat duty [kJ/hr]

S maximum allowable stress of the shell material at design temperature [pounds/inch ]

S maximum allowable stress of the shell material at design temperature [pounds/inch ]

t Wall thickness of vessel [inches]



t Thickness to withstand seismic and wind

65

66 7. Conclusions & Recommendations

U Overall heat transfer coefficient [kJ/hr*m *C]

V Volume of vessel [m ]

wt% Weight percent

AUnit sizing

In this appendix all different technique for size estimation are explained. To enhance readability ex-ample calculations regarding the conventional process are included.

A.1. Contactor (C-101)The contactor is sized using the method proposed in Seider et al[16]. Later it is checked using AspenHysys simulations.

𝐷 = √ 4 ∗ 𝐺(𝑓𝑈 ) ∗ 𝜋 ∗ 𝜌 (A.1)

With:G = Mass flow rate of gas [kg/s]f*U = fraction of the vapor flooding velocity [m/s]𝜌 = Density of vapor [kg/m ]

The vapor flooding velocity is calculated using the correlation proposed by Fair et al [53], whichwas edited by Seider et al [16]. This results in a contactor diameter of 2.04 m. Aspen Hysys givesan estimate of 2.3 meters. The height of packing coming from Aspen Hysys simulations is 3.5 meters.For Mellapack ©packing from Sulzur Corp. the HETP is defined in the range of 0.5 to 0.7 meters[54].Using 6 theoretical stages this results in a range of 2.1 to 4.2 meters of packing height. For this projecta packing height of 3 meters is used and a diameter of 2.3 meters. As the packing is assumed to be25% of the contactor the total height is estimated to be 12 meters. The wall thickness t is calculatedto be 20 cm using the Sieder et al [16] method which uses equation A.3. In this equation the designpressure is considered to be 1.1 times the operating pressure since the operating pressure is above1000 psig. For vertical columns wind and seismic loads are to be taken into account,too. The thicknessof vessel required to withstand these effects have been calculated using the following equation[16]:

𝑡 = 0.22 ∗ (𝐷 + 18) ∗ 𝐿𝑆 ∗ 𝐷 (A.2)

With:D = external vessel diameter [inches]t =Wall thickness of vessel [inches]S = maximum allowable stress of the shell material at design temperature [pounds/inch ]L = tangent-to-tangent height of the column[inches].Where the term 18 ( in inches) accounts for the column cage ladders. This method assumes a windload based on the wind velocity of 140 miles/hr acting uniformly over the height of the column.

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68 A. Unit sizing

The wall thickness to withstand pressure is calculated using the ASME pressure vessel code formula[16]:

𝑡 = 𝑃 ∗ 𝐷2 ∗ 𝑆 ∗ 𝐸 − 1.2 ∗ 𝑃 (A.3)

With:P = internal design pressure [psig]S = maximum allowable stress of the shell material at design temperature [pounds/inch ]E = Fractional weld efficiency

With the following assumptions:

• For pressures between 0-5 psig, P has been taken to be 10psig.[16]

• For pressures between 10 psig to 1000 psig, the following equation has been used: P =exp{0.60608+ 0.91615[ln(P )]+0.0015655[ln(P )] }[16]

• Maximum allowable stress of carbon steel has been taken to be 15000 pounds/inch [16]

• Minimum thickness has been assumed in all cases to be 6mm. [16]

The average vessel thickness t is calculated as the average of t and t +t as described in Seideret al [16]. The t will be needed at the top of the vessel and t +t at the bottom. A linear gradient ofwall thickness is assumed.

A.2. Vessel sizing (V201, V202 & V203)All vessel sizing is done via the Biegler-Grossman-Westerberg method [55]. Firstly the volume of thedrum is calculated using the following equation.

𝑉 = ( 1𝐿𝑖𝑞𝑢𝑖𝑑𝐹𝑟𝑎𝑐𝑡𝑖𝑜𝑛) ∗ (

𝐹 ∗ 𝜏𝜌 ) (A.4)

With:F = liquid flowrate [kg/hr] V =Volume of vessel [m ]𝜏 = residence time [hr]𝜌 = Density liquid [kg/m ]

With the following assumptions:

• For V-201 and V-203, the liquid fraction has been assumed to be 0.8, whereas that for V-202 thesame has been considered to be 0.5.

• The residence times for vessels V-201,202 and 203 have been taken as 10, 5 and 20 min respec-tively.

• The flowrates and the densities for the respective streams have been taken from Aspen Hysys.See Appendix C.

Which gives the following results for the surge, flash & reboiler.

The aspect ratio, is assumed to be 4 as described in Biegler et al [55].

Which gives the following results for the flash, reboiler & surge.

A.3. Heat exchangers (E-201,202 & 203) 69

Table A.1: Vessel volumes

Vessel Volume [m ] Diameter [m] Length [m]V-201 0.535 0.554 2.217V-202 0.465 0.529 2.117V-203 1.16 0.719 2.875

Vessel Wall thickness [mm]V-201 6V-202 6V-203 6

Table A.2: Thickness of the wall of all different Vessels

A.3. Heat exchangers (E-201,202 & 203)Aspen Hysys simulations were used to get the total surface area needed for the heat exchangers E-201& E-202. Calculation of area of Sea-Water Cooler E-203 was done manually as follows:

• The heat duty was taken from Hysys simulations which is 3.726·10 kJ/h.

• The water inlet and outlet were assumed to be at 10 °C and 20 °C respectively.The approach of10°C has been been taken from a cooling tower vendor website [56]

• Accordingly, the flow if sea-water required was calculated to be 8898.9 kg/hr (Heat Capacity ofsea-water is assumed 4.187 kJ/(kg°C))[9]

• The inlet and oulet temperatures for the lean TEG solution were taken from Hysys, which are81.85 °C and 33.85°C respectively.

• The log-mean-temperature difference for counter-current heat-exchange was thus calculated tobe 39.87 °C.

• The overall heat-transfer coefficient was conservatively assumed to be 150 W/(m .K) [57]

• Accordingly, the area required for this heat exchanger was calculated to be 17.3 m .

Which is used in the following equations:

𝑞 = 𝑈 ∗ 𝐴 ∗ 𝐿𝑀𝑇𝐷[58] (A.5)

𝐿𝑀𝑇𝐷 = Δ𝑇 − Δ𝑇𝑙𝑛( )

[58] (A.6)

The results are displayed in table A.3.

Heat exchanger Surface area [m ]E-201 28.45E-202 147.0E-203 17.3

Table A.3: Total surface area needed per heat exchanger

70 A. Unit sizing

A.4. Still Column (C-201)The still column has been sized using following the method given in [16]. The equation used is:

𝐷 = √4 ∗ 𝐺

(𝑓𝑈 ) ∗ (1 − )𝜋 ∗ 𝜌(A.7)

With:A = Downcomer area,A = Tower inside cross-sectional area,

The fraction A /A is calculated as per the following equations:

𝐴𝐴 = 0.1 (A.8)

if F , the gas flooding velocity <= 0.1

𝐴𝐴 = 0.1 + 𝐹 − 0.1

9 (A.9)

if 0.1<= F <= 1.0 &𝐴𝐴 = 2 (A.10)

if F >= 1.0. This results in Still Column Diameter of 0.277 m or 27.7 cm and height of 6.5 m (whichincludes tray spacing height, height for disengagement at the top and height of holdup of 5min at thebottom assuming it is not mounted directly on reboiler).

The wall thickness for the still column has been calculated on the same lines as that of the contactor,but by using criteria of lower operating pressures. The average column thickness is thus estimated tobe 10 mm.

A.5. Pumps (P-101 A/B and 202 A/B)The head requirement for individual pump was calculated by using the Hydrostatic Equation:

Δ𝑃 = ℎ ∗ 𝜌 ∗ 𝑔[59] (A.11)

With:Δ P = Pressure rise in the pump[kPa],h = height of liquid column [m],𝜌 =density of the liquid [kg/m ].The power requirement for the two- pumps was obtained as a result of Hysys simulation.

Finally, all of this has been tabulated in table A.4:

Pump Head [mlc] Power [kW]P-101A/B 1370 13.4P-202A/B 20 0.155

Table A.4: Power requirement per pump

A.6. Pervaporation membrane module (S-202)The pervaporation membrane module sizing will be based on the commercial PVM-094 SS 316 7×4-tube(120cm) from Pervatech shown in the figure A.1, which displays the dimensions of it in the image.

As mentioned in the figure A.1, the diameter of a module with 7 elements of 25 mm diame-ter each is totally 0.1143 m (114.3 mm). Therefore, the circular area of the vessel tube is around

A.6. Pervaporation membrane module (S-202) 71

(pi/4)·0.1143 =0.01 m . Hence, if there are 7 elements, each element (plus the space needed sur-rounding it for the water vapour flow) is 0.01/7=0.0014 m .

In our case, it is required a number of 37 elements per module, so 0.0014·37=0.053 m of circularsurface, which transformed into diameter is 0.260 m (260mm) of vessel tube.

Then, as stated in table 3.5, 509 m are needed. The module designed will provide 3.7 m ofeffective membrane are, representing 509 / 3.7 = 138 modules. It is assumed that there is no especialrequirements for the space such as a particular length or height. Hence, it was selected a rectangular14x10 modules disposition in parallel. As we only need 138 modules, there is space for 2 more modules.

The separation between modules is calculated as follows. The figure A.1 shows that for a PVM-094SS 316 7×4-tube module the height is 100 mm from the center of the tube. From those 100 mm, wesubtract 114.3 / 2 = 57.15 mm of radius, leading to 42.85 mm of height taken from the outer part ofthe vessel circumference until the highest point of the tube to be added to the diameter. Therefore,260 mm + 42.85 mm = 302.85 mm, around 0.302 m of actual diameter of flange. If 14 modules areset in parallel, the total width is 14 · 0.302 = 4.24 m. However, a security factor of 50% is taken inorder to count the pipes needed between modules for the vapour flow as well as maintenance duties,resulting in 6.36 m, which is normalized to 7 m width.

For the height, we have 10 modules in parallel resulting in 10 · 0.302 = 3.02 m. Following the samereasoning, the security factor of 50% is taken. The total height is 4.53 m, which is normalized to 5 m.

Furthermore, the length will be taken as equal due to the fact that the membrane length and typeis the same (silica membrane of 120 cm) as in the PVM-094 SS 316 7×4-tube module. Hence, thelength will be 1.405 m.

Figure A.1: Dimensions of PVM-094 SS 316 7×4-tube (120cm) from Pervatech.

The thickness required for each module is sized using the method proposed in Seider et al [16],considering that each module is an empty cylindrical vessel of SS 316 of 0.260 m diameter.

Due to the fact that thickness should be sufficiently big to withstand the vacuum collapsing pressure,Mulet et. al presented a method for computing the necessary wall thickness t , based in the vessellength-to-outside diameter ratio.

72 A. Unit sizing

𝑡 = 1.3 ∗ 𝐷 ( 𝑃 ∗ 𝐿𝐸 ∗ 𝐷 ) . (A.12)

With:D = outside diameter [inches]E = modulus of elasticity [psi], 27.6·10 for SS 316. [60]P = internal design pressure [psig] for operating pressures between 0 and 5, 10 psig should be taken[16]. L = vessel length [inches]

However, to the value of t the following correction, t must be added

𝑡 = 𝐿 ∗ (0.18 ∗ 𝐷 − 2.2) ∗ 10 − 0.19 (A.13)

Therefore, the total thickness for a vacuum vessel is

𝑡 = 𝑡 + 𝑡 (A.14)

The results are displayed in table A.5.

Table A.5: Results for thickness pervaporation module vessel calculation

Type t [mm] t 𝐶 [mm] t [mm]Vessel 1.4 4.6 6.0

BUsed graphs

73

74 B. Used graphs

The incoming lean TEG is assumed to be in equilibrium with the outgoing dry gas. This graph, there-fore, provides the minimum concentration of lean TEG required for dehydration when the Contactortemperature (which is inlet gas temperature assuming the contactor to be isothermal) and Equilibriumwater dew point of gas obtainable at temperature is known.

Figure B.1: Equilibrium Water Dew Point in °C versus Inlet Gas Temperature [15]

75

From the water content of the outgoing dehydrated gas, its dew point at the contactor temperatureand pressure is calculated using this graph. A conservative approach of about 8.5 °C [15]is subtractedfrom the dew point estimated from the graph.

Figure B.2: Water Content of Sweet Natural Gas , kg/(10 std m ) (100 kPa and 15 °C) vs Water Dewpoint in °C [15]

CFlow sheet conventional design

77

78 C. Flow sheet conventional design

FigureC.1:

Thetotalflow

sheetand

modelused

inhysys,the

mass

balancesare

inthe

following

appendices

DStream Summary - Conventional

Design Case

Table D.1: Stream Summary - Conventional Design

Name <001> <002> <101> <102> <103> <104> DRY GASVapour Fraction 0 0 1 1 0 0 1Temperature [C] 35 35 35 35 35 35 35Pressure [bar] 157 157 157 157 157 157 156Molar Flow [kgmole/h] 555090 556744 19438 17784 18 26 17776Mass Flow [kg/h] 9999999 10043330 380657 337325 2594 2717 337203Liq Volume Flow [m3/h] 10020 10110 1112 1022 2 2 1021Heat Flow [kJ/h] (*10^5) -158126,43 -158436,62 -1783,75 -1473,70 -14,23 -16,23 -1471,69Name <201> <202> <203> <204> Waste <205> <206>Vapour Fraction 0 0 1,56E-02 1 0 0 1,99E-04Temperature [C] 55 94 98 98 98 98 98Pressure [bar] 156 156 4 4 4 4 3Molar Flow [kgmole/h] 26 26 26 0 0 25 25Mass Flow [kg/h] 2717 2717 2717 10 0 2707 2707Liq Volume Flow [m3/h] 2 2 2 0 0 2 2Heat Flow [kJ/h] -16,07 -15,75 -15,75 -0,05 0,00 -15,70 -15,70Name <207> <208> <209> <210> <211> <212> <213>Vapour Fraction 0 0 1 0 0 0 0Temperature [C] 170 204 201 201 199 199 123Pressure [bar] 3 1 1 1 1 3 2Molar Flow [kgmole/h] 25 19 1 18 18 18 18Mass Flow [kg/h] 2707 2587 30 2567 2592 2592 2594Liq Volume Flow [m3/h] 2 2 0 2 2 2 2Heat Flow [kJ/h] -15,10 -13,01 -0,22 -12,84 -12,97 -12,97 -13,59Name <214> <215> Make Up OVHDVapour Fraction 0 0 0 1Temperature [C] 82 34 35 98Pressure [bar] 2 1 1 1Molar Flow [kgmole/h] 18 18 0 8Mass Flow [kg/h] 2594 2594 24 149Liq Volume Flow [m3/h] 2 2 0 0Heat Flow [kJ/h] -13,91 -14,28 -0,13 -1,80

79

80 D. Stream Summary - Conventional Design Case

Table D.2: Mass fraction design case conventional 1/2

Name <001> <002> <101> <102> <103> <104> DRY GASMethane 0,0000 0,0017 0,7087 0,7501 0,0000 0,0016 0,7504Ethane 0,0000 0,0001 0,0819 0,0892 0,0000 0,0002 0,0892Propane 0,0000 0,0000 0,0491 0,0545 0,0000 0,0004 0,0545n-Butane 0,0000 0,0000 0,0264 0,0296 0,0000 0,0002 0,0296n-Pentane 0,0000 0,0000 0,0089 0,0100 0,0000 0,0001 0,0100n-Hexane 0,0000 0,0000 0,0033 0,0037 0,0000 0,0000 0,0037n-Heptane 0,0000 0,0000 0,0038 0,0043 0,0000 0,0000 0,0043n-Octane 0,0000 0,0000 0,0044 0,0049 0,0000 0,0000 0,0049n-Nonane 0,0000 0,0000 0,0049 0,0055 0,0000 0,0000 0,0055Benzene 0,0000 0,0000 0,0003 0,0002 0,0000 0,0001 0,0002Toluene 0,0000 0,0000 0,0004 0,0003 0,0000 0,0003 0,0003m-Xylene 0,0000 0,0000 0,0005 0,0005 0,0000 0,0007 0,0005E-Benzene 0,0000 0,0000 0,0005 0,0005 0,0000 0,0006 0,0005TEGlycol 0,0000 0,0000 0,0000 0,0000 0,9932 0,9385 0,0001H2O 1,0000 0,9957 0,0000 0,0004 0,0067 0,0547 0,0000Nitrogen 0,0000 0,0000 0,0026 0,0028 0,0000 0,0000 0,0028CO2 0,0000 0,0025 0,0805 0,0166 0,0000 0,0008 0,0166i-Butane 0,0000 0,0000 0,0146 0,0164 0,0000 0,0009 0,0164i-Pentane 0,0000 0,0000 0,0092 0,0104 0,0000 0,0007 0,0104Name <201> <202> <203> <204> Waste <205> <206>Methane 0,0016 0,0016 0,0016 0,4325 0,0001 0,0001 0,0001Ethane 0,0002 0,0002 0,0002 0,0564 0,0000 0,0000 0,0000Propane 0,0004 0,0004 0,0004 0,0837 0,0001 0,0001 0,0001n-Butane 0,0002 0,0002 0,0002 0,0412 0,0001 0,0001 0,0001n-Pentane 0,0001 0,0001 0,0001 0,0192 0,0001 0,0001 0,0001n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0001 0,0001 0,0001 0,0017 0,0001 0,0001 0,0001Toluene 0,0003 0,0003 0,0003 0,0023 0,0003 0,0003 0,0003m-Xylene 0,0007 0,0007 0,0007 0,0020 0,0007 0,0007 0,0007E-Benzene 0,0006 0,0006 0,0006 0,0018 0,0006 0,0006 0,0006TEGlycol 0,9385 0,9385 0,9385 0,0004 0,9420 0,9420 0,9420H2O 0,0547 0,0547 0,0547 0,0398 0,0548 0,0548 0,0548Nitrogen 0,0000 0,0000 0,0000 0,0014 0,0000 0,0000 0,0000CO2 0,0008 0,0008 0,0008 0,1479 0,0003 0,0003 0,0003i-Butane 0,0009 0,0009 0,0009 0,1103 0,0005 0,0005 0,0005i-Pentane 0,0007 0,0007 0,0007 0,0592 0,0005 0,0005 0,0005Name <207> <208> <209> <210> <211> <212> <213>Methane 0,0001 0,0000 0,1443 0,0000 0,0000 0,0000 0,0000Ethane 0,0000 0,0000 0,0186 0,0000 0,0000 0,0000 0,0000Propane 0,0001 0,0000 0,0272 0,0000 0,0000 0,0000 0,0000n-Butane 0,0001 0,0000 0,0129 0,0000 0,0000 0,0000 0,0000n-Pentane 0,0001 0,0000 0,0062 0,0000 0,0000 0,0000 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0001 0,0000 0,0004 0,0000 0,0000 0,0000 0,0000Toluene 0,0003 0,0000 0,0007 0,0000 0,0000 0,0000 0,0000m-Xylene 0,0007 0,0000 0,0014 0,0000 0,0000 0,0000 0,0000E-Benzene 0,0006 0,0000 0,0013 0,0000 0,0000 0,0000 0,0000TEGlycol 0,9420 0,9895 0,3378 0,9931 0,9932 0,9932 0,9932H2O 0,0548 0,0105 0,3467 0,0067 0,0067 0,0067 0,0067Nitrogen 0,0000 0,0000 0,0005 0,0000 0,0000 0,0000 0,0000CO2 0,0003 0,0000 0,0483 0,0000 0,0000 0,0000 0,0000i-Butane 0,0005 0,0000 0,0351 0,0000 0,0000 0,0000 0,0000i-Pentane 0,0005 0,0000 0,0185 0,0000 0,0000 0,0000 0,0000

81

Table D.3: Mass fraction design case conventional 2/2

Name <214> <215> Make Up OVHDMethane 0,0000 0,0000 0,0000 0,0296Ethane 0,0000 0,0000 0,0000 0,0040Propane 0,0000 0,0000 0,0000 0,0068n-Butane 0,0000 0,0000 0,0000 0,0037n-Pentane 0,0000 0,0000 0,0000 0,0023n-Hexane 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000Benzene 0,0000 0,0000 0,0000 0,0025Toluene 0,0000 0,0000 0,0000 0,0058m-Xylene 0,0000 0,0000 0,0000 0,0124E-Benzene 0,0000 0,0000 0,0000 0,0110TEGlycol 0,9932 0,9932 0,9940 0,0000H2O 0,0067 0,0067 0,0060 0,8797Nitrogen 0,0000 0,0000 0,0000 0,0001CO2 0,0000 0,0000 0,0000 0,0142i-Butane 0,0000 0,0000 0,0000 0,0154i-Pentane 0,0000 0,0000 0,0000 0,0125

EStream Summary - Turndown Case

Table E.1: Stream summary turndown case hybrid

Name <001> <002> <101> <102> <103> <104> DRY GASVapour Fraction 0 0 1 1 0 0 1Temperature [C] 35 35 35 35 32 35 35Pressure [bar] 157 157 157 157 157 157 156Molar Flow [kgmole/h] 55509 55674 1944 1778 6 7 1777Mass Flow [kg/h] 1000000 1004333 38062 33729 877 897 33709Liquid Volume Flow [m3/h] 1002 1011 111 102 1 1 102Heat Flow [kJ/h] [*10^5] -158126,45 -158437,17 -1783,58 -1473,56 -48,10 -50,29 -1471,37Name <201> <202> <203> <204> WASTE <205> <206>Vapour Fraction 0 0 0 1 0 0 0Temperature [C] 55 92 96 96 96 96 96Pressure [bar] 156 156 4 4 4 4 3Molar Flow [kgmole/h] 7 7 7 0 0 7 7Mass Flow [kg/h] 897 897 897 6 0 891 891Liquid Volume Flow [m3/h] 1 1 1 0 0 1 1Heat Flow [kJ/h] [*10^5] -49,75 -48,77 -48,77 -0,25 0,00 -48,52 -48,52Name <207> <208> <209> <210> <211> <212> <213>Vapour Fraction 0 0 1 0 0 0 0Temperature [C] 176 204 199 199 198 198 117Pressure [bar] 3 1 1 1 1 3 2Molar Flow [kgmole/h] 7 6 1 6 6 6 6Mass Flow [kg/h] 891 884 15 875 882 882 877Liquid Volume Flow [m3/h] 1 1 0 1 1 1 1Heat Flow [kJ/h] [*10^5] -46,35 -44,42 -1,01 -43,66 -44,06 -44,06 -46,00Name <214> <215> MAKE UP OVHDVapour Fraction 0 0 0 1Temperature [C] 80 31 35 90Pressure [bar] 2 2 1 1Molar Flow [kgmole/h] 6 6 0 1Mass Flow [kg/h] 877 877 7 22Liquid Volume Flow [m3/h] 1 1 0 0Heat Flow [kJ/h] [*10^5] -46,98 -48,27 -0,40 -2,04

83

84 E. Stream Summary - Turndown Case

Table E.2: Mass fraction turndown case hybrid 1/2

Name <001> <002> <101> <102> <103> <104> DRY GASMethane 0,0000 0,0017 0,7088 0,7502 0,0000 0,0033 0,7506Ethane 0,0000 0,0001 0,0819 0,0892 0,0000 0,0006 0,0892Propane 0,0000 0,0000 0,0491 0,0545 0,0000 0,0007 0,0545n-Butane 0,0000 0,0000 0,0264 0,0296 0,0000 0,0003 0,0296n-Pentane 0,0000 0,0000 0,0089 0,0100 0,0000 0,0002 0,0100n-Hexane 0,0000 0,0000 0,0033 0,0037 0,0000 0,0000 0,0037n-Heptane 0,0000 0,0000 0,0038 0,0043 0,0000 0,0000 0,0043n-Octane 0,0000 0,0000 0,0044 0,0049 0,0000 0,0000 0,0049n-Nonane 0,0000 0,0000 0,0049 0,0055 0,0000 0,0000 0,0055Benzene 0,0000 0,0000 0,0003 0,0002 0,0000 0,0002 0,0002Toluene 0,0000 0,0000 0,0004 0,0003 0,0000 0,0005 0,0003m-Xylene 0,0000 0,0000 0,0005 0,0005 0,0001 0,0008 0,0004E-Benzene 0,0000 0,0000 0,0005 0,0005 0,0001 0,0007 0,0005TEGlycol 0,0000 0,0000 0,0000 0,0000 0,9941 0,9692 0,0001H2O 1,0000 0,9957 0,0000 0,0004 0,0056 0,0202 0,0000Nitrogen 0,0000 0,0000 0,0026 0,0028 0,0000 0,0000 0,0028CO2 0,0000 0,0025 0,0805 0,0165 0,0000 0,0010 0,0165i-Butane 0,0000 0,0000 0,0145 0,0164 0,0000 0,0012 0,0164i-Pentane 0,0000 0,0000 0,0092 0,0104 0,0000 0,0010 0,0103Name <201> <202> <203> <204> WASTE <205> <206>Methane 0,0033 0,0033 0,0033 0,4854 0,0001 0,0001 0,0001Ethane 0,0006 0,0006 0,0006 0,0859 0,0000 0,0000 0,0000Propane 0,0007 0,0007 0,0007 0,0832 0,0001 0,0001 0,0001n-Butane 0,0003 0,0003 0,0003 0,0346 0,0001 0,0001 0,0001n-Pentane 0,0002 0,0002 0,0002 0,0154 0,0001 0,0001 0,0001n-Hexane 0,0000 0,0000 0,0000 0,0001 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0001 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0001 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0002 0,0002 0,0002 0,0018 0,0002 0,0002 0,0002Toluene 0,0005 0,0005 0,0005 0,0024 0,0005 0,0005 0,0005m-Xylene 0,0008 0,0008 0,0008 0,0020 0,0008 0,0008 0,0008E-Benzene 0,0007 0,0007 0,0007 0,0018 0,0007 0,0007 0,0007TEGlycol 0,9692 0,9692 0,9692 0,0005 0,9756 0,9756 0,9756H2O 0,0202 0,0202 0,0202 0,0161 0,0203 0,0203 0,0203Nitrogen 0,0000 0,0000 0,0000 0,0009 0,0000 0,0000 0,0000CO2 0,0010 0,0010 0,0010 0,1174 0,0002 0,0002 0,0002i-Butane 0,0012 0,0012 0,0012 0,0978 0,0006 0,0006 0,0006i-Pentane 0,0010 0,0010 0,0010 0,0544 0,0006 0,0006 0,0006Name <207> <208> <209> <210> <211> <212> <213>Methane 0,0001 0,0000 0,1886 0,0000 0,0000 0,0000 0,0000Ethane 0,0000 0,0000 0,0332 0,0000 0,0000 0,0000 0,0000Propane 0,0001 0,0000 0,0318 0,0000 0,0000 0,0000 0,0000n-Butane 0,0001 0,0000 0,0129 0,0000 0,0000 0,0000 0,0000n-Pentane 0,0001 0,0000 0,0059 0,0000 0,0000 0,0000 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0002 0,0000 0,0008 0,0000 0,0000 0,0000 0,0000Toluene 0,0005 0,0000 0,0017 0,0000 0,0000 0,0000 0,0000m-Xylene 0,0008 0,0001 0,0045 0,0001 0,0001 0,0001 0,0001E-Benzene 0,0007 0,0001 0,0042 0,0001 0,0001 0,0001 0,0001TEGlycol 0,9756 0,9893 0,3262 0,9941 0,9941 0,9941 0,9941H2O 0,0203 0,0104 0,2878 0,0056 0,0057 0,0057 0,0056Nitrogen 0,0000 0,0000 0,0003 0,0000 0,0000 0,0000 0,0000CO2 0,0002 0,0000 0,0450 0,0000 0,0000 0,0000 0,0000i-Butane 0,0006 0,0000 0,0368 0,0000 0,0000 0,0000 0,0000i-Pentane 0,0006 0,0000 0,0202 0,0000 0,0000 0,0000 0,0000

85

Table E.3: Mass fraction turndown case hybrid 2/2

Name <214> <215> MAKE UP OVHDMethane 0,0000 0,0000 0,0000 0,1314Ethane 0,0000 0,0000 0,0000 0,0242Propane 0,0000 0,0000 0,0000 0,0259n-Butane 0,0000 0,0000 0,0000 0,0112n-Pentane 0,0000 0,0000 0,0000 0,0061n-Hexane 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000Benzene 0,0000 0,0000 0,0000 0,0091Toluene 0,0000 0,0000 0,0000 0,0193m-Xylene 0,0001 0,0001 0,0000 0,0304E-Benzene 0,0001 0,0001 0,0000 0,0270TEGlycol 0,9941 0,9941 0,9940 0,0000H2O 0,0056 0,0056 0,0060 0,5889Nitrogen 0,0000 0,0000 0,0000 0,0002CO2 0,0000 0,0000 0,0000 0,0398i-Butane 0,0000 0,0000 0,0000 0,0488i-Pentane 0,0000 0,0000 0,0000 0,0376

FMicrowave heating model

Figure F.1: Model used in Hysys to estimate energy consumption in a microwave heated column

87

GSplit flow model

89

90 G. Split flow model

FigureG.1:

Modelused

inHysys

tomodelsplit

flowinjection

inthe

absorptioncolum

n

HModel used for hybrid system

91

92 H. Model used for hybrid system

FigureH.1:

Thetotalflow

sheetand

modelused

inhysys,the

mass

balancesare

inthe

following

appendices

IStream Summary - Hybrid: Design

Flow

93

94 I. Stream Summary - Hybrid: Design Flow

Table I.1: Stream summary design case hybrid

Name <102> DRY GAS <104> <201> <202> <204>Vapour Fraction 1,0000 1,0000 0,0000 0,0000 0,0000 1,0000Temperature [C] 35 36 35 36 38 42Pressure [bar] 157 156 157 156 156 4Molar Flow [kgmole/h] 17784 17777 18 18 18 0Mass Flow [kg/h] 337306 337197 1660 1660 1660 3Liq Volume Flow [m3/h] 1022 1021 1 1 1 0Heat Flow [kJ/h] -1,47E+09 -1,47E+09 -1,04E+07 -1,04E+07 -1,04E+07 -1,53E+04Name Waste <205> <203> <206> <207> OVHDVapour Fraction 0,0000 0 8,14E-03 9,35E-05 4,14E-04 1Temperature [C] 42 42 42 42 108 70Pressure [bar] 4 4 4 3 3 1Molar Flow [kgmole/h] 0 18 18 18 18 0Mass Flow [kg/h] 0 1657 1660 1657 1657 3Liq Volume Flow [m3/h] 0 1 1 1 1 0Heat Flow [kJ/h] 0,00E+00 -1,04E+07 -1,04E+07 -1,04E+07 -1,01E+07 -1,54E+04Name <208> <209> <210> <213> <212> Make UpVapour Fraction 0,0000 1,0000 0,0000 0,0000 0,0000 0,0000Temperature [C] 204 203 203 57 198 35Pressure [bar] 1 1 1 2 3 1Molar Flow [kgmole/h] 5 0 5 5 5 0Mass Flow [kg/h] 763 3 761 786 785 24Liq Volume Flow [m3/h] 1 0 1 1 1 0Heat Flow [kJ/h] -3,81E+06 -1,84E+04 -3,79E+06 -4,27E+06 -3,93E+06 -1,33E+05Name <211> <214> <215> <103> <204.2> OVHD-1Vapour Fraction 0,0000 0 0 0 1 1Temperature [C] 198 52 35 37 42 42Pressure [bar] 1 2 2 156 4 4Molar Flow [kgmole/h] 5 5 5 5 0 0Mass Flow [kg/h] 785 786 786 786 1 3Liq Volume Flow [m3/h] 1 1 1 1 0 0Heat Flow [kJ/h] -3,93E+06 -4,28E+06 -4,32E+06 -4,30E+06 -3,07E+03 -1,23E+04Name <101> <207.1> <207.2> <207.3> <207.4> <207.5>Vapour Fraction 1,0000 0,0048 0,0056 5,64E-03 0,0000 0,0000Temperature [C] 35 150 150 150 159 159Pressure [bar] 157 3 2 2 157 157Molar Flow [kgmole/h] 19438 18 11 5 5 5Mass Flow [kg/h] 380629 1657 1527 764 764 765Liq Volume Flow [m3/h] 1112 1 1 1 1 1Heat Flow [kJ/h] -1,78E+09 -9,86E+06 -7,86E+06 -3,93E+06 -3,90E+06 -3,91E+06Name <207.6> <207.7>Vapour Fraction 5,64E-03 4,75E-03Temperature [C] 150 150Pressure [bar] 2 2Molar Flow [kgmole/h] 5 5Mass Flow [kg/h] 764 764Liq Volume Flow [m3/h] 1 1Heat Flow [kJ/h] -3,93E+06 -3,93E+06

95

Table I.2: Mass fraction design case 1/2

Name <102> <104> <201> <202> <204> Waste <205>Methane 0,7502 0,0011 0,0011 0,0011 0,5557 0,0000 0,0000Ethane 0,0892 0,0001 0,0001 0,0001 0,0585 0,0000 0,0000Propane 0,0545 0,0003 0,0003 0,0003 0,0933 0,0001 0,0001n-Butane 0,0296 0,0002 0,0002 0,0002 0,0455 0,0001 0,0001n-Pentane 0,0100 0,0001 0,0001 0,0001 0,0139 0,0001 0,0001n-Hexane 0,0037 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0043 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0049 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0055 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0002 0,0001 0,0001 0,0001 0,0004 0,0001 0,0001Toluene 0,0003 0,0002 0,0002 0,0002 0,0004 0,0002 0,0002m-Xylene 0,0005 0,0007 0,0007 0,0007 0,0003 0,0007 0,0007E-Benzene 0,0005 0,0006 0,0006 0,0006 0,0002 0,0006 0,0006TEGlycol 0,0000 0,9101 0,9101 0,9101 0,0000 0,9119 0,9119H2O 0,0004 0,0845 0,0845 0,0845 0,0050 0,0847 0,0847Nitrogen 0,0028 0,0000 0,0000 0,0000 0,0028 0,0000 0,0000CO2 0,0166 0,0007 0,0007 0,0007 0,1503 0,0004 0,0004i-Butane 0,0164 0,0007 0,0007 0,0007 0,0531 0,0006 0,0006i-Pentane 0,0104 0,0006 0,0006 0,0006 0,0207 0,0005 0,0005Name <203> <206> <207> OVHD <208> <209> <210>Methane 0,0011 0,0000 0,0000 0,1184 0,0000 0,1250 0,0000Ethane 0,0001 0,0000 0,0000 0,0129 0,0000 0,0128 0,0000Propane 0,0003 0,0001 0,0001 0,0871 0,0000 0,0242 0,0000n-Butane 0,0002 0,0001 0,0001 0,0761 0,0000 0,0178 0,0000n-Pentane 0,0001 0,0001 0,0001 0,0721 0,0000 0,0114 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0001 0,0001 0,0001 0,0273 0,0003 0,0222 0,0002Toluene 0,0002 0,0002 0,0002 0,0220 0,0003 0,0189 0,0002m-Xylene 0,0007 0,0007 0,0007 0,0174 0,0003 0,0161 0,0002E-Benzene 0,0006 0,0006 0,0006 0,0197 0,0003 0,0183 0,0003TEGlycol 0,9101 0,9119 0,9119 0,0000 0,9912 0,3358 0,9928H2O 0,0845 0,0847 0,0847 0,1793 0,0073 0,3070 0,0062Nitrogen 0,0000 0,0000 0,0000 0,0847 0,0000 0,0007 0,0000CO2 0,0007 0,0004 0,0004 0,1109 0,0000 0,0374 0,0000i-Butane 0,0007 0,0006 0,0006 0,0904 0,0001 0,0257 0,0000i-Pentane 0,0006 0,0005 0,0005 0,0816 0,0001 0,0268 0,0000Name <213> <212> Make Up <211> <214> <215> <103>Methane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Ethane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Propane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Butane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Pentane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0002 0,0002 0,0000 0,0002 0,0002 0,0002 0,0002Toluene 0,0002 0,0002 0,0000 0,0002 0,0002 0,0002 0,0002m-Xylene 0,0002 0,0002 0,0000 0,0002 0,0002 0,0002 0,0002E-Benzene 0,0003 0,0003 0,0000 0,0003 0,0003 0,0003 0,0003TEGlycol 0,9928 0,9928 0,9920 0,9928 0,9928 0,9928 0,9928H2O 0,0062 0,0062 0,0080 0,0062 0,0062 0,0062 0,0062Nitrogen 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000CO2 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Butane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Pentane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000

96 I. Stream Summary - Hybrid: Design Flow

Table I.3: Mass fraction design case 2/2

Name <204.2> OVHD-1 <101> <207.1> <207.2> <207.3> <207.4>Methane 0,5554 0,5557 0,7088 0,0000 0,0000 0,0000 0,0000Ethane 0,0585 0,0585 0,0819 0,0000 0,0000 0,0000 0,0000Propane 0,0933 0,0933 0,0491 0,0001 0,0003 0,0003 0,0003n-Butane 0,0455 0,0455 0,0264 0,0001 0,0003 0,0003 0,0003n-Pentane 0,0139 0,0139 0,0089 0,0001 0,0003 0,0003 0,0003n-Hexane 0,0000 0,0000 0,0033 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0038 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0044 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0049 0,0000 0,0000 0,0000 0,0000Benzene 0,0004 0,0004 0,0003 0,0001 0,0003 0,0003 0,0003Toluene 0,0004 0,0004 0,0004 0,0002 0,0003 0,0003 0,0003m-Xylene 0,0003 0,0003 0,0005 0,0007 0,0003 0,0003 0,0003E-Benzene 0,0002 0,0002 0,0005 0,0006 0,0004 0,0004 0,0004TEGlycol 0,0000 0,0000 0,0000 0,9119 0,9895 0,9895 0,9895H2O 0,0050 0,0050 0,0000 0,0847 0,0069 0,0069 0,0069Nitrogen 0,0028 0,0028 0,0026 0,0000 0,0004 0,0004 0,0004CO2 0,1504 0,1503 0,0805 0,0004 0,0004 0,0004 0,0004i-Butane 0,0532 0,0531 0,0145 0,0006 0,0004 0,0004 0,0004i-Pentane 0,0207 0,0207 0,0092 0,0005 0,0004 0,0004 0,0004Name <207.5> <207.6> <207.7> DRY GAS <001> <002>Methane 0,0000 0,0000 0,0000 0,7504 0,0000 0,0017Ethane 0,0000 0,0000 0,0000 0,0892 0,0000 0,0001Propane 0,0003 0,0003 0,0003 0,0545 0,0000 0,0000n-Butane 0,0003 0,0003 0,0003 0,0296 0,0000 0,0000n-Pentane 0,0003 0,0003 0,0003 0,0100 0,0000 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0037 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0043 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0049 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0055 0,0000 0,0000Benzene 0,0003 0,0003 0,0003 0,0002 0,0000 0,0000Toluene 0,0003 0,0003 0,0003 0,0003 0,0000 0,0000m-Xylene 0,0003 0,0003 0,0003 0,0005 0,0000 0,0000E-Benzene 0,0004 0,0004 0,0004 0,0005 0,0000 0,0000TEGlycol 0,9895 0,9895 0,9895 0,0001 0,0000 0,0000H2O 0,0069 0,0069 0,0069 0,0000 1,0000 0,9957Nitrogen 0,0004 0,0004 0,0004 0,0028 0,0000 0,0000CO2 0,0004 0,0004 0,0004 0,0166 0,0000 0,0025i-Butane 0,0004 0,0004 0,0004 0,0164 0,0000 0,0000i-Pentane 0,0004 0,0004 0,0004 0,0104 0,0000 0,0000

JStream Summary - Hybrid:

Turndown Case

97

98 J. Stream Summary - Hybrid: Turndown Case

Table J.1: Stream summary hybrid system turndown case

Name <102> Dry Gas <104> <201> <202> <204>Vapour Fraction 1,0000 1,0000 0,0000 0,0000 0,0000 1,0000Temperature [C] 35 37 35 36 41 45Pressure [bar] 157 156 157 156 156 4Molar Flow [kgmole/h] 755 755 4 4 4 0Mass Flow [kg/h] 16189 16183 452 452 452 3Liq Volume Flow [m3/h] 46 46 0 0 0 0Heat Flow [kJ/h] -6,39E+07 -6,38E+07 -2,53E+06 -2,53E+06 -2,52E+06 -9,80E+03Name Waste <205> <203> <206> <207> OVHDVapour Fraction 0 0 3,34E-02 3,84E-04 1,51E-03 1Temperature [C] 45 45 45 45 121 35Pressure [bar] 4 4 4 3 2,994208 1Molar Flow [kgmole/h] 0 3 4 3 3 0Mass Flow [kg/h] 0 449 452 449 449 1Liq Volume Flow [m3/h] 0 0 0 0 0 0Heat Flow [kJ/h] 0,00E+00 -2,51E+06 -2,52E+06 -2,51E+06 -2,41E+06 -2,13E+03Name <208> <209> <210> Make Up <211> <212>Vapour Fraction 0,0000 1 0,00E+00 0,00E+00 4,33E-04 0Temperature [C] 204 204 204 35 203 203Pressure [bar] 1 1 1 1 1 3Molar Flow [kgmole/h] 2 0 2 0 2 2Mass Flow [kg/h] 221 0 221 2 223 223Liq Volume Flow [m3/h] 0 0 0 0 0 0Heat Flow [kJ/h] -1,10E+06 -1,90E-02 -1,10E+06 -1,10E+04 -1,11E+06 -1,11E+06Name <204.1> <101> <103> <213> <214> <215>Vapour Fraction 1,0000 1,0000 0 0 0 0Temperature [C] 45 35 37 51 41 35Pressure [bar] 4 157 156 2 2 1Molar Flow [kgmole/h] 0 1944 2 2 2 2Mass Flow [kg/h] 0 38063 223 223 223 223Liq Volume Flow [m3/h] 0 111 0 0 0 0Heat Flow [kJ/h] 0,00E+00 -1,78E+08 -1,22E+06 -1,21E+06 -1,22E+06 -1,23E+06Name <204.2> <OVHD-1> <207.1> <207.2> <207.3> <207.4>Vapour Fraction 1 1 3,84E-03 1,19E-02 1,19E-02 0,0000Temperature [C] 45 45 146 150 150 166Pressure [bar] 4 4 2 2 2 157Molar Flow [kgmole/h] 0 0 3 3 2 2Mass Flow [kg/h] 0 3 449 444 222 222Liq Volume Flow [m3/h] 0 0 0 0 0 0Heat Flow [kJ/h] 0,00E+00 -9,80E+03 -2,38E+06 -2,28E+06 -1,14E+06 -1,13E+06Name <207.5> <207.6> <207.7>Vapour Fraction 0,0000 1,19E-02 1,06E-02Temperature [C] 166 150 150Pressure [bar] 157 2 2Molar Flow [kgmole/h] 2 2 2Mass Flow [kg/h] 223 222 222Liq Volume Flow [m3/h] 0 0 0Heat Flow [kJ/h] -1,13E+06 -1,14E+06 -1,14E+06

99

Table J.2: Mass fraction hybrid turndown 1/2

Name <102> Dry Gas <104> <201> <202> <204> WasteMethane 0,6052 0,6054 0,0032 0,0032 0,0032 0,5065 0,0001Ethane 0,1238 0,1238 0,0009 0,0009 0,0009 0,1351 0,0001Propane 0,0959 0,0959 0,0011 0,0011 0,0011 0,1409 0,0003n-Butane 0,0581 0,0581 0,0005 0,0005 0,0005 0,0575 0,0001n-Pentane 0,0203 0,0203 0,0003 0,0003 0,0003 0,0192 0,0001n-Hexane 0,0077 0,0077 0,0000 0,0000 0,0000 0,0003 0,0000n-Heptane 0,0090 0,0090 0,0000 0,0000 0,0000 0,0002 0,0000n-Octane 0,0103 0,0103 0,0000 0,0000 0,0000 0,0001 0,0000n-Nonane 0,0115 0,0115 0,0000 0,0000 0,0000 0,0001 0,0000Benzene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Toluene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000m-Xylene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000E-Benzene 0,0003 0,0003 0,0003 0,0003 0,0003 0,0001 0,0003TEGlycol 0,0000 0,0002 0,9704 0,9704 0,9704 0,0000 0,9763H2O 0,0004 0,0000 0,0194 0,0194 0,0194 0,0017 0,0195Nitrogen 0,0032 0,0032 0,0000 0,0000 0,0000 0,0014 0,0000CO2 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Butane 0,0334 0,0333 0,0023 0,0023 0,0023 0,0987 0,0017i-Pentane 0,0210 0,0210 0,0016 0,0016 0,0016 0,0380 0,0014Name <205> <203> <206> <207> OVHD <208> <209>Methane 0,0001 0,0032 0,0001 0,0001 0,1520 0,0000 0,0209Ethane 0,0001 0,0009 0,0001 0,0001 0,1494 0,0000 0,0367Propane 0,0003 0,0011 0,0003 0,0003 0,1437 0,0000 0,0511n-Butane 0,0001 0,0005 0,0001 0,0001 0,1351 0,0001 0,0501n-Pentane 0,0001 0,0003 0,0001 0,0001 0,1367 0,0001 0,0729n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Toluene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000m-Xylene 0,0000 0,0000 0,0000 0,0000 0,0009 0,0000 0,0020E-Benzene 0,0003 0,0003 0,0003 0,0003 0,0126 0,0005 0,0256TEGlycol 0,9763 0,9704 0,9763 0,9763 0,0000 0,9928 0,2852H2O 0,0195 0,0194 0,0195 0,0195 0,0284 0,0064 0,2632Nitrogen 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000CO2 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Butane 0,0017 0,0023 0,0017 0,0017 0,1277 0,0001 0,0907i-Pentane 0,0014 0,0016 0,0014 0,0014 0,1134 0,0001 0,1017Name <210> Make Up <211> <212> <213> <214> <215>Methane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Ethane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Propane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Butane 0,0001 0,0000 0,0001 0,0001 0,0001 0,0001 0,0001n-Pentane 0,0001 0,0000 0,0001 0,0001 0,0001 0,0001 0,0001n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Toluene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000m-Xylene 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000E-Benzene 0,0005 0,0000 0,0005 0,0005 0,0005 0,0005 0,0005TEGlycol 0,9928 0,9920 0,9928 0,9928 0,9928 0,9928 0,9928H2O 0,0064 0,0080 0,0064 0,0064 0,0064 0,0064 0,0064Nitrogen 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000CO2 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Butane 0,0001 0,0000 0,0001 0,0001 0,0001 0,0001 0,0001i-Pentane 0,0001 0,0000 0,0001 0,0001 0,0001 0,0001 0,0001

100 J. Stream Summary - Hybrid: Turndown Case

Table J.3: Mass fraction hybrid turndown 2/2

Name <103> <204.2> <OVHD-1> <101> <207.1> <207.2> <207.3>Methane 0,0000 0,5065 0,5065 0,7088 0,0001 0,0005 0,0005Ethane 0,0000 0,1351 0,1351 0,0819 0,0001 0,0005 0,0005Propane 0,0000 0,1409 0,1409 0,0491 0,0003 0,0005 0,0005n-Butane 0,0001 0,0575 0,0575 0,0264 0,0001 0,0005 0,0005n-Pentane 0,0001 0,0192 0,0192 0,0089 0,0001 0,0005 0,0005n-Hexane 0,0000 0,0003 0,0003 0,0033 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0002 0,0002 0,0038 0,0000 0,0000 0,0000n-Octane 0,0000 0,0001 0,0001 0,0044 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0001 0,0001 0,0049 0,0000 0,0000 0,0000Benzene 0,0000 0,0000 0,0000 0,0003 0,0000 0,0000 0,0000Toluene 0,0000 0,0000 0,0000 0,0004 0,0000 0,0000 0,0000m-Xylene 0,0000 0,0000 0,0000 0,0005 0,0000 0,0000 0,0000E-Benzene 0,0005 0,0001 0,0001 0,0005 0,0003 0,0005 0,0005TEGlycol 0,9928 0,0000 0,0000 0,0000 0,9763 0,9895 0,9895H2O 0,0064 0,0017 0,0017 0,0000 0,0195 0,0064 0,0064Nitrogen 0,0000 0,0014 0,0014 0,0026 0,0000 0,0000 0,0000CO2 0,0000 0,0000 0,0000 0,0805 0,0000 0,0000 0,0000i-Butane 0,0001 0,0988 0,0987 0,0145 0,0017 0,0005 0,0005i-Pentane 0,0001 0,0381 0,0380 0,0092 0,0014 0,0005 0,0005Name <207.4> <207.5> <207.6> <207.7>Methane 0,0005 0,0005 0,0005 0,0005Ethane 0,0005 0,0005 0,0005 0,0005Propane 0,0005 0,0005 0,0005 0,0005n-Butane 0,0005 0,0005 0,0005 0,0005n-Pentane 0,0005 0,0005 0,0005 0,0005n-Hexane 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000Benzene 0,0000 0,0000 0,0000 0,0000Toluene 0,0000 0,0000 0,0000 0,0000m-Xylene 0,0000 0,0000 0,0000 0,0000E-Benzene 0,0005 0,0005 0,0005 0,0005TEGlycol 0,9895 0,9895 0,9895 0,9895H2O 0,0064 0,0064 0,0064 0,0064Nitrogen 0,0000 0,0000 0,0000 0,0000CO2 0,0000 0,0000 0,0000 0,0000i-Butane 0,0005 0,0005 0,0005 0,0005i-Pentane 0,0005 0,0005 0,0005 0,0005

KStream Summary - Hybrid: Max

Flow Case

101

102 K. Stream Summary - Hybrid: Max Flow Case

Table K.1: Stream summary max flow case hybrid

Name Dry Gas <104> <201> <202> <204> WasteVapour Fraction 1,0000 0,0000 0,0000 0,0000 1,0000 0,0000Temperature [C] 36 35 36 41 45 45Pressure [bar] 156 157 156 156 4 4Molar Flow [kgmole/h] 21664 22 22 22 0 0Mass Flow [kg/h] 413320 2042 2042 2042 5 0Liq Volume Flow [m3/h] 1244 2 2 2 0 0Heat Flow [kJ/h] -1,83E+09 -1,28E+07 -1,28E+07 -1,28E+07 -2,46E+04 0,00E+00Name <205> <203> <206> <207> OVHD <208>Vapour Fraction 0,0000 8,95E-03 1,06E-04 8,37E-04 1 0Temperature [C] 45 45 45 115 70 204Pressure [bar] 4 4 3 3 1 1Molar Flow [kgmole/h] 22 22 22 22 0 7Mass Flow [kg/h] 2038 2042 2038 2038 4 937Liq Volume Flow [m3/h] 2 2 2 2 0 1Heat Flow [kJ/h] -1,28E+07 -1,28E+07 -1,28E+07 -1,23E+07 -2,06E+04 -4,67E+06Name <209> <210> <211> Make up <212> <213>Vapour Fraction 1,0000 0,0000 0,0000 0,0000 0,0000 0,0000Temperature [C] 203 203 197 35 197 47Pressure [bar] 1 1 1 157 3 2Molar Flow [kgmole/h] 0 6 7 0 7 7Mass Flow [kg/h] 4 935 974 39 974 974Liq Volume Flow [m3/h] 0 1 1 0 1 1Heat Flow [kJ/h] -2,32E+04 -4,65E+06 -4,87E+06 -2,14E+05 -4,87E+06 -5,31E+06Name <214> <215> <103> <204.2> OVHD-1 <101>Vapour Fraction 0,0000 0 0 1 1 1,0000Temperature [C] 37 19 20 45 45 35Pressure [bar] 2 1 156 4 4 157Molar Flow [kgmole/h] 7 7 7 0 0 23325Mass Flow [kg/h] 974 974 974 1 4 456755Liq Volume Flow [m3/h] 1 1 1 0 0 1334Heat Flow [kJ/h] -5,34E+06 -5,39E+06 -5,37E+06 -4,92E+03 -1,97E+04 -2,14E+09Name <102> <207.1> <207.2> <207.3> <207.4> <207.5>Vapour Fraction 1,0000 0,0053 0,0034 0,0034 0,0000 0Temperature [C] 35 143 150 150 156 156Pressure [bar] 157 2 2 2 157 157Molar Flow [kgmole/h] 21673 22 13 7 7 7Mass Flow [kg/h] 413455 2038 1876 938 938 934Liq Volume Flow [m3/h] 1244 2 2 1 1 1Heat Flow [kJ/h] -1,83E+09 -1,22E+07 -9,64E+06 -4,82E+06 -4,79E+06 -4,77E+06Name <207.6> <207.7>Vapour Fraction 0,0034 1,98E-03Temperature [C] 150 150Pressure [bar] 2 2Molar Flow [kgmole/h] 7 7Mass Flow [kg/h] 938 938Liq Volume Flow [m3/h] 1 1Heat Flow [kJ/h] -4,82E+06 -4,82E+06

103

Table K.2: Mass fraction max flow case 1/2

Name Dry Gas <104> <201> <202> <204> Waste <205>Methane 0,7428 0,0012 0,0012 0,0012 0,4740 0,0000 0,0000Ethane 0,0879 0,0001 0,0001 0,0001 0,0502 0,0000 0,0000Propane 0,0535 0,0003 0,0003 0,0003 0,0836 0,0001 0,0001n-Butane 0,0290 0,0002 0,0002 0,0002 0,0424 0,0001 0,0001n-Pentane 0,0098 0,0001 0,0001 0,0001 0,0139 0,0001 0,0001n-Hexane 0,0036 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0042 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0048 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0054 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0003 0,0001 0,0001 0,0001 0,0005 0,0001 0,0001Toluene 0,0004 0,0003 0,0003 0,0003 0,0004 0,0003 0,0003m-Xylene 0,0005 0,0007 0,0007 0,0007 0,0003 0,0007 0,0007E-Benzene 0,0005 0,0006 0,0006 0,0006 0,0003 0,0006 0,0006TEGlycol 0,0001 0,9102 0,9102 0,9102 0,0000 0,9123 0,9123H2O 0,0000 0,0839 0,0839 0,0839 0,0059 0,0841 0,0841Nitrogen 0,0028 0,0000 0,0000 0,0000 0,0023 0,0000 0,0000CO2 0,0283 0,0012 0,0012 0,0012 0,2485 0,0006 0,0006i-Butane 0,0160 0,0007 0,0007 0,0007 0,0554 0,0005 0,0005i-Pentane 0,0102 0,0006 0,0006 0,0006 0,0222 0,0005 0,0005Name <203> <206> <207> OVHD <208> <209> <210>Methane 0,0012 0,0000 0,0000 0,1116 0,0000 0,1183 0,0000Ethane 0,0001 0,0000 0,0000 0,0122 0,0000 0,0122 0,0000Propane 0,0003 0,0001 0,0001 0,1048 0,0000 0,0250 0,0000n-Butane 0,0002 0,0001 0,0001 0,0938 0,0001 0,0202 0,0000n-Pentane 0,0001 0,0001 0,0001 0,0900 0,0000 0,0133 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0001 0,0001 0,0001 0,0339 0,0004 0,0283 0,0002Toluene 0,0003 0,0003 0,0003 0,0273 0,0004 0,0241 0,0003m-Xylene 0,0007 0,0007 0,0007 0,0216 0,0004 0,0206 0,0003E-Benzene 0,0006 0,0006 0,0006 0,0207 0,0004 0,0196 0,0003TEGlycol 0,9102 0,9123 0,9123 0,0000 0,9913 0,3223 0,9929H2O 0,0839 0,0841 0,0841 0,1617 0,0068 0,2757 0,0058Nitrogen 0,0000 0,0000 0,0000 0,0006 0,0000 0,0006 0,0000CO2 0,0012 0,0006 0,0006 0,1387 0,0000 0,0636 0,0000i-Butane 0,0007 0,0005 0,0005 0,0964 0,0001 0,0276 0,0000i-Pentane 0,0006 0,0005 0,0005 0,0868 0,0001 0,0285 0,0000Name <211> Make up <212> <213> <214> <215> <103>Methane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Ethane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Propane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Butane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Pentane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Hexane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000Benzene 0,0002 0,0000 0,0002 0,0002 0,0002 0,0002 0,0002Toluene 0,0003 0,0000 0,0003 0,0003 0,0003 0,0003 0,0003m-Xylene 0,0003 0,0000 0,0003 0,0003 0,0003 0,0003 0,0003E-Benzene 0,0003 0,0000 0,0003 0,0003 0,0003 0,0003 0,0003TEGlycol 0,9932 0,9990 0,9932 0,9932 0,9932 0,9932 0,9932H2O 0,0056 0,0010 0,0056 0,0056 0,0056 0,0056 0,0056Nitrogen 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000CO2 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Butane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000i-Pentane 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000 0,0000

104 K. Stream Summary - Hybrid: Max Flow Case

Table K.3: Mass fraction max flow case 2/2

Name <204.2> OVHD-1 <101> <102> <207.1> <207.2> <207.3>Methane 0,4740 0,4740 0,7088 0,7425 0,0000 0,0000 0,0000Ethane 0,0502 0,0502 0,0819 0,0878 0,0000 0,0000 0,0000Propane 0,0836 0,0836 0,0491 0,0535 0,0001 0,0004 0,0004n-Butane 0,0424 0,0424 0,0264 0,0290 0,0001 0,0004 0,0004n-Pentane 0,0140 0,0139 0,0089 0,0098 0,0001 0,0004 0,0004n-Hexane 0,0000 0,0000 0,0033 0,0036 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0038 0,0042 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0044 0,0048 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0049 0,0054 0,0000 0,0000 0,0000Benzene 0,0005 0,0005 0,0003 0,0003 0,0001 0,0004 0,0004Toluene 0,0004 0,0004 0,0004 0,0004 0,0003 0,0004 0,0004m-Xylene 0,0003 0,0003 0,0005 0,0005 0,0007 0,0004 0,0004E-Benzene 0,0003 0,0003 0,0005 0,0005 0,0006 0,0004 0,0004TEGlycol 0,0000 0,0000 0,0000 0,0000 0,9123 0,9895 0,9895H2O 0,0059 0,0059 0,0000 0,0004 0,0841 0,0065 0,0065Nitrogen 0,0023 0,0023 0,0026 0,0028 0,0000 0,0000 0,0000CO2 0,2486 0,2485 0,0805 0,0283 0,0006 0,0004 0,0004i-Butane 0,0555 0,0554 0,0145 0,0160 0,0005 0,0004 0,0004i-Pentane 0,0222 0,0222 0,0092 0,0102 0,0005 0,0004 0,0004Name <207.4> <207.5> <207.6> <207.7>Methane 0,0000 0,0000 0,0000 0,0000Ethane 0,0000 0,0000 0,0000 0,0000Propane 0,0004 0,0004 0,0004 0,0004n-Butane 0,0004 0,0004 0,0004 0,0004n-Pentane 0,0004 0,0004 0,0004 0,0004n-Hexane 0,0000 0,0000 0,0000 0,0000n-Heptane 0,0000 0,0000 0,0000 0,0000n-Octane 0,0000 0,0000 0,0000 0,0000n-Nonane 0,0000 0,0000 0,0000 0,0000Benzene 0,0004 0,0004 0,0004 0,0004Toluene 0,0004 0,0004 0,0004 0,0004m-Xylene 0,0004 0,0004 0,0004 0,0004E-Benzene 0,0004 0,0004 0,0004 0,0004TEGlycol 0,9895 0,9895 0,9895 0,9895H2O 0,0065 0,0065 0,0065 0,0065Nitrogen 0,0000 0,0000 0,0000 0,0000CO2 0,0004 0,0004 0,0004 0,0004i-Butane 0,0004 0,0004 0,0004 0,0004i-Pentane 0,0004 0,0004 0,0004 0,0004

LHAZOP and FEI

Figure L.1: Point 2 op the HAZOP is at the natural gas outflow from the contactor

Figure L.2: Point 1 op the HAZOP is between the pervaporation membranes and the pumps. Point 3is at the TEG outflow of the Surge.

105

106 L. HAZOP and FEI

TableL.1:

HAZO

P

No.

Guide

word

Deviation

Possible

causeConsequences

Safeguardaction1

No

Noflow

Pumpsshut

down

Noseparation

inthe

membranes

Backuppum

ppresent

pipeclogged

Regularflushing

ofthe

pipesMore

More

flowPum

pspum

ptoo

hardless

separationwilltake

placeConcentration

controlLess

water

passesthrough

themembranes

Lowerquality

ofTEG

FLowcontroler

withalarm

LessLess

flowLeakage

TEGisleaving

thesystem

uncontrolledLeak

detectionFlow

measurem

enttodetect

lossesReverse

Reverseflow

Leakingthrough

membranes

Noregeneration

valvesthat

preventreverse

flowBroken

pump

Changedpressure

difference2

No

Noflow

Gaswellhas

shutdow

nNodehydration

atall

TEGloop

shouldalso

shutdow

nValve

isclosed

LessLess

flowLeaking

ofgas

Lossofgas

Alarmongas

outflowGasleaves

throughTEG

outletCom

paregasoutflow

withinflow

Aswellas

Bothwater

andLean

TEGcontained

toomuch

water

Gasisnot

driedenough

TEGquality

controlgas

inthe

streamToo

shortresidence

time

Setamaxim

umgas

inflow3

LessLess

flowLow

TEGlevelin

surgeInterupted

TEGrecycle

Direct

TEGaddition

LeakBad

dehydrationfrom

freshsource

No

Noflow

Empty

surgeNodehydration

processAlarm

onlow

TEGlevel

Brokenpum

pBack

uppum

pBack

upTEG

storageMore

More

FlowPum

pworks

toohard

Toomuch

TEGincirculation

Maxim

umflow

onpum

psTEG

outletisopen

Surgelevelw

illdecreaseControlindication

forthe

outlet

107

Fire & Explosion Index

Area/Country: Division: Location Date

Norway - -

Site Manufacturing Unit Process Unit

- TEG dehydrogenation Contactor

Materials in Process Unit

Natural gas, water, tri ethyleneglycol

State of Operation Basic Materials for Material Factor

Normal operation Methane

Material Factor 21

1. General Process Hazards Penalty Factor Penalty

Range Used

Base Factor 1,00 1,00

A. Exothermic Chemical Reactions 0.30 - 1.25 0,00

B. Endothermic Processes 0.20 - 0.40 0,00

C. Material Handling and Transfer 0.25 - 1.05 0,85

D. Enclosed or Indoor Process Units 0.25 - 0.90 0,00

E. Acces 0.20 - 0.35 0,35

F. Drainage and Spill Control 0.25 - 0.50 0,50

General Process Hazards Factor (F1) 2,70

2. Special Process Hazards Penalty Factor Penalty

Range Used

Base Factor 1,00 1,00

A. Toxic Material(s) 0.20 - 0.80 0,20

B. Sub-Atmosferic Pressure (< 500 mm Hg) 0,50 0,00

C. Operation In or Near Flammable Range

1. Tank Farms Storage Flammable Liquids 0,50 0,00

2. Process Upset or Purge Failure 0,30 0,00

3. Always in Flammable Range 0,80 0,00

D. Dust Explosion 0.25 - 2.00 0,00

E. Pressure Operating Pressure: 156,5 kPa 0,48

Relief Setting: 180 kPa

F. Low Temperature 0.20 - 0.30 0,00

G. Quantity of Flammable Material: 139852 lb

Hc = 21,5*10^3 kcal/kg

1. Liquids or Gases in Process 3,00

2. Liquids or Gases in Storage 0,00

3. Combustible Solids in Storage, Dust in Process 0,00

H. Corrosion and Erosion 0.10 - 0.75 0,10

I. Leakage - Joints and Packing 0.10 - 1.50 0,30

J. Use of Fired Equipment 0,10

K. Hot Oil Heat Exchange System 0.15 - 1.15 0,00

L. Rotating Equipment 0,50 0,00

Special Process Hazards Factor (F2) 5,18

Process Units Hazards Factor (F1 x F2) = F3 13,99

Fire and Explosion Index (F3 x MF = F&EI) 294

Figure L.3: DOW fire and explosion index on the contactor using Methane as reference material for ithas the highest material factor

MEquipment Summary

109

REACTORS, COLUMNS & VESSELS – SUMMARY

EQUIPMENT NR. :

NAME :

C-101

Contactor :

C-201

Still Column :

C-202

Stripping

Column :

V-201

Flash Vessel :

V-202

Reboiler :

Packed

Column

Tray Column Packed

Column

Horizontal Horizontal

Pressure [bara] : 156.25/156.5 1/1.1 1.1 4.5 1.1

Temp. [oC] : 35 70.3/204 204 42 204

Volume [m3] :

Diameter [m] :

L or H [m] :

2.04

12.2

0.15

6

0.25

0.5

0.31 (1)

0.46

1.85

0.14 (2)

0.35

1.4

Internals

- Tray Type :

- Tray Number :

- Fixed Packing

Type :

Shape :

- Catalyst

Type :

Shape :

-

-

-

n.a.

n.a.

Mellapack.

n.a.

n.a.

n.a.

Sieve Tray

2

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

Mellapack

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

Gas Fired

Number

- Series :

- Parallel :

1

-

1

-

1

-

1

-

1

-

Materials of

Construction (3) :

Column: SS Column: CS

Tray: SS

Column: CS

CS Shell: CS

Tubes:

CS/Inconel

Other :

Remarks:

(1) V-201: For Residence time of 10 min and 80% Liquid filled.

(2) V-202: For Residence time of 5 min and 50% Liquid filled.

(3) SS = Stainless Steel; CS = Carbon Steel

Designers :

Project ID-Number : CPD3425

Date : June 2015

REACTORS, COLUMNS & VESSELS – SUMMARY

EQUIPMENT NR. :

NAME :

V-203

Surge Vessel :

S-201 A/B

Filter

S-202

Pervaporation

(3)

Horizontal In Line Horizontal

Pressure [bara] : 1 4.5/3.5 (4)

Temp. [oC] : 202 42 150

Volume [m3] :

Diameter [m] :

L or H [m] :

0.34 (1)

0.48

1.9

-

0.0254

-

0.074

0.26

1.402

Internals

- Tray Type :

- Tray Number :

- Fixed Packing

Type :

Shape :

- Catalyst

Type :

Shape :

- Tubes

Type :

- Type

-

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

Inline Strainer

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

Number

- Series :

- Parallel :

1

-

1

-

-

138

Materials of

Construction (2) :

CS SS SS

Other :

Remarks:

(1) SS = Stainless Steel; CS = Carbon Steel

(2) V-203: For residence time of 20 min and 80% liquid filled.

(3) Data for pervaporation membrane module only.

(4) 3 bar in feed, 20 mbar in permeate side and 1.5 bar in retentate.

Designers :


Date : June 2015

HEAT EXCHANGERS & FURNACES – SUMMARY

EQUIPMENT NR. :

NAME :

E-201

Glycol/Glycol

Preheater :

E-202

Glycol/Glycol

Heater :

E-203

Sea-Water

Cooler :

E-204

Pervaporation

Heater

Shell and

Tube

Shell and

Tube

Shell and Tube Shell and Tube

Substance

- Tubes :

- Shell :

Rich TEG

Lean TEG

Rich TEG

Lean TEG

Cooling Water.

Lean TEG

Rich TEG

LP Steam

Duty [kW] : 2.8 93.36 11.37 61.31

Heat Exchange

area [m2] :

4.24 (1)

24.35(1)

2.6(1)

2.44(1)

Number

- Series :

- Parallel : :

1

-

1

-

1

-

1

-

Pressure [bara]

- Tubes :

- Shell :

5

2.5

3.5

2.5

4

2

3

6.5

Temperature

In / Out [oC]

- Tubes :

- Shell :

36 / 38

57 / 52

42 / 107.8

198/ 57

10/20

53 / 35

107.8/150

162

Special Materials of

Construction (2) :

Tubes : CS

Shell : CS

Tubes : CS

Shell : CS

Tubes : CS

Shell : CS

Tubes : CS

Shell : CS

Other :

Remarks:

(1) Bare tube surface.

(2) CS = Carbon Steel;

Designers :


Date : June 2015

PUMPS, BLOWERS & COMPRESSORS – SUMMARY

EQUIPMENT NR. :

NAME :

P-101

Turbocharger

P-102 A/B

High

Pressure

Pump

P-103 A/B

Semi-Lean

Injection

Pump :

P-201 A/B

Intermediate

Pump :

P-202 A/B

Booster

Pump

Type :

Number :

-

1

Centrifugal

2

Centrifugal

2

Centrifugal

2

Centrifugal

2

Medium

transferred :

Rich TEG / Lean

TEG/Semi-Lean

TEG

Lean TEG

Semi-Lean

TEG

Semi-Lean

TEG

Lean TEG

Capacity

[kg/s] :

[m3/h] :

2.5/0.8/0.7

0.8

0.7

1.2

0.8

Density [kg/m3] : 705.1/1133/1042 1133 1042 636.3 969.6

Pressure [bara]

Suct. / Disch. :

(156.5-4.5)

&(1.5-78)&

(1.5-77.5)

78 / 156.5

1.1/156.5

1.5/2

1/2.5

Temperature

In / Out [oC] :

42/37/160

36/37

150/160

150/150

198

Power [kW]

- Theor. :

- Actual :

2.04

2.17

0.027

0.045

Number

- Theor. :

- Actual :

1

2 (1)

2 (1)

2 (1)

2 (1)


Construction :

SS 316

SS 316

SS 316

SS 316

SS 316

Other : Double

mechanical seals

Double

mechanical

seals

Double

mechanical

seals

Double

mechanical

seals

Double

mechanical

seals

Remarks:

(1) One installed spare included.

Designers :


Date : June 2015

PUMPS, BLOWERS & COMPRESSORS – SUMMARY

EQUIPMENT NR. :

NAME :

P-203 A/B

Vacuum Pump

Type :

Number :

-

1

Medium

transferred :

Water Vapour

Capacity

[kg/s] :

[m3/h] :

252.3

Density [kg/m3] : 1

Pressure [bara]

Suct. / Disch. :

0.02/1

Temperature

In / Out [oC] :

150/150

Power [kW]

- Theor. :

- Actual :

49

Number

- Theor. :

- Actual :

2 (1)


Construction :

SS 316

Other : Double

mechanical seals

Remarks:

(1) One installed spare included.

Designers :


Date : June 2015

COLUMN – SPECIFICATION SHEET

EQUIPMENT NUMBER : C-101

NAME : Contactor

General Data

Service : - distillation / extraction / absorption /

Column Type : - packed / tray / spray /

Tray Type : - cap / sieve / valve /

Tray Number (1)

- Theoretical : 6

- Actual : -

- Feed (actual) : Top and Middle (1st and 4

th theoretical trays)

Tray Distance (HETP) [m] : 0.61 Tray Material : SS314 (2)

Column Diameter [m] : 2.04 Column Material : SS (2)

Column Height [m] : 12.2

Heating : - none / open steam / reboiler /

Process Conditions

Stream Details Feed Gas Feed Liquid Dry Gas

Rich Liquid

Extractant /

side stream Lean

TEG

Semi

Lean

TEG

Temp. [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 35

156.5

159.5

380617

:36.5

156.5

1133

786.4

160

156.5

1042

764.8

: 35.7

156.3

158.7

3.372E+05

: 35.4

156.5

1125

1660

Composition mol% wt% wt% wt% mol% wt% mol% wt% mol% wt%

TEG

Water

Other

0

0.4

99.6

99.2

0.62

0.18

98.95

0.69

0.33

0.01

0

99.99

91.01

8.45

0.54

Column Internals (3)

Trays Not Applicable

Number of

caps / sieve holes / : …

Active Tray Area [m2] : …

Weir Length [mm] : …

Diameter of

chute pipe / hole / [mm] : …

Packing

Type : Mellapack

Material :

Volume [m3] : 9.8 (Total)

Length [m] :-

Width [m] :-

Height [m] : 3 (2 beds of 1.5 m)

Remarks:

(1) Tray numbering from top to bottom.

(2) SS = Stainless Steel; CS = Carbon Steel.

(3) Sketch & measures of Column & Tray layout should have been provided.

Designers :


Date : June 2015

DISTILLATION COLUMN – SPECIFICATION SHEET


NAME : Still Column

General Data




Tray Number (1)

- Theoretical : 2

- Actual : 2

- Feed (actual) : 2

Tray Distance (HETP) [m] : 0.61 Tray Material : SS314 (2)

Column Diameter [m] : 0.145 Column Material : CS (2)

Column Height [m] : 6

Heating : - none / open steam / reboiler / Natural Gas (3)

Process Conditions

Stream Details Feed Top Bottom Reflux /

Absorbent

Extractant /

side stream Liq Gas

Temp. [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 150

2

636.3

763.6

202.9

1.1

0.9

2.811

: 70.3

1

1.13

3.23

: 204

1.1

962.4

763.2

: 70.3

1

972.6

1.018

Composition wt% wt% mol% wt% mol% wt% mol% wt% mol% wt%

TEG

Water

Other

98.95

0.69

0.36

33.6

30.71

35.7

0

17.93

82.07

99.12

0.73

0.15

0.01

99.88

0.02


Trays (5)

Number of




Diameter of


Packing Not Applicable

Type :

Material :

Volume [m3] :

Length [m] :

Width [m] :

Height [m] :

Remarks:



(3) Reboiler is V-202; operates with Natural Gas


(5) Tray layout valid for whole column.

Designers :


Date : June 2015

COLUMN – SPECIFICATION SHEET


NAME : Stripping Column

General Data




Tray Number (1)

- Theoretical : 1

- Actual : 1

- Feed (actual) : 1

Tray Distance (HETP) [m] : - Tray Material : SS314 (2)

Column Diameter [m] : 0.25 Column Material : CS (2)

Column Height [m] : 0.5

Heating : - none / open steam / reboiler / Natural Gas

Process Conditions

Stream Details Feed Top Bottom Reflux /

Absorbent

Extractant /

side stream Liq Gas

Temp. [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 204

1.1

962.4

763.2

42.14

4.5

3.86

0.7

: 203

1.1

0.9

2.8

: 203

1.1

964.2

761

:

Composition wt% wt% mol% wt% mol% wt% mol% wt% mol% wt%

TEG

Water

Other

99.12

0.73

0.15

0

0.5

99.5

33.58

30.7

35.72

99.2

0.6

0.2


Trays Not Applicable

Number of




Diameter of


Packing

Type : Mellapack

Material :-

Volume [m3] :0.012

Length [m] :-

Width [m] :-

Height [m] :0.25

Remarks:




Designers :


Date : June 2015

HEAT EXCHANGER – SPECIFICATION SHEET

EQUIPMENT NUMBER : E-201 In Series : 1

NAME : Glycol/Glycol Preheater In Parallel : none

General Data

Service : - Heat Exchanger - Vaporizer

- Cooler - Reboiler

- Condenser (Air cooled) (1), (2), (3)

Type : - Fixed Tube Sheets - Plate Heat Exchanger

- Floating Head - Finned Tubes

- Hair Pin - Thermosyphon

- Double Tube -

Position : - Horizontal

- Vertical

Capacity [kW] : 2.85 (1)

Heat Exchange Area [m2] : 4.24 (1)

Overall Heat Transfer Coefficient [W/m2oC] : 333.28 (1)

Log. Mean Temperature Diff. (LMTD) [oC] :

Passes Tube Side : 1

Passes Shell Side : n.a.

Correction Factor LMTD (min. 0.75) :

Corrected LMTD [oC] : 7.257 (1)

Process Conditions

Medium :

Mass Stream [kg/hr] :

Mass Stream to

- Evaporize [kg/s] :

- Condense [kg/s] :

Average Specific Heat [kJ/kgoC] :

Heat of Evap. / Condensation [kJ/kg] :

Temperature IN [oC] :

Temperature OUT [oC] :

Pressure [bara] :

Material :

Shell Side Tube Side

Lean TEG solution

787

n.a.

3

-

57

52

2.5

C.S

Rich TEG solution

1660

n.a

3

-

36

38

5

CS

Remarks:

(1) Calculation of Air Cooler: “Applied Chemical Process Design”, F. Aerstin and G. Street.

(2) Cooler requires 40 x 40 meters plot space, which may not be available.

(3) Requires Fan(s) for forced air circulation with 960 kW for electrical drive(s).

(1) As simulated in Aspen Hysys.

Designers :


Date : June 2015



NAME : Glycol/Glycol Heater In Parallel : none

General Data


- Cooler - Reboiler

- Condenser




- Double Tube -


- Vertical

Capacity [kW] : 93.36 (1)

Heat Exchange Area [m2] : 24.35 (1)

Overall Heat Transfer Coefficient [W/m2oC] : 327.8 (1)

Log. Mean Temperature Diff. (LMTD) [oC] :


Passes Shell Side : n.a

Correction Factor LMTD (min. 0.75) : Corrected LMTD [

oC] : 42.13 (1)

Process Conditions

Medium :


Mass Stream to


- Condense [kg/s] :





Pressure [bara] :

Material :


Rich TEG

786.4

-

-

3

-

198.0

57.0

2.5

CS

Lean TEG

1657

-

-

3

-

42

107.8

3.5

CS

Remarks:

(1) As simulated in Aspen Hysys.

Designers :


Date : June 2015



NAME : Sea Water Cooler In Parallel : none

General Data


- Cooler - Reboiler

- Condenser




- Double Tube -


- Vertical

Capacity [kW] : 11.37 (Aspen)

Heat Exchange Area [m2] : 2.64 (Calc.)

Overall Heat Transfer Coefficient [W/m2oC] : 150 (Assumed).

Log. Mean Temperature Diff. (LMTD) [oC] : 28.68 (Calc.)




Corrected LMTD [oC] :

Process Conditions

Medium :


Mass Stream to


- Condense [kg/s] :





Pressure [bara] :

Material (1) :


Lean TEG solution

786.4

-

-

3

-

53

35

2

CS

Sea Water

978.03

-

-

4.18

-

10

20

4

C.S

Remarks:


Designers :


Date : June 2015



NAME : Pervaporation Heater In Parallel : none

General Data


- Cooler - Reboiler

- Condenser




- Double Tube -


- Vertical

Capacity [kW] : 61.31 (Aspen)

Heat Exchange Area [m2] : 2.44 (Calc.)

Overall Heat Transfer Coefficient [W/m2oC] : 900 (Assumed).

Log. Mean Temperature Diff. (LMTD) [oC] : 27.8 (Calc.)




Corrected LMTD [oC] :

Process Conditions

Medium :


Mass Stream to

- Condense [kg/hr]

- Evaporate [kg/s] :





Pressure [bara] :

Material (1) :


Steam

106.02

106.02

-

2075.11

162.06

162.06

6.5

CS

Rich TEG solution

1657

-

-

3

-

107.8

150

3

CS

Remarks:


Designers :


Date : June 2015

CENTRIFUGAL PUMP – SPECIFICATION SHEET

EQUIPMENT NUMBER : P-101 Operating : 1

NAME : Turbocharger Installed Spare : 0

Service : TEG Solution

Type :

Number : 1

Operating Conditions & Physical Data

Pumped liquid : TEG Rich/TEG Lean/TEG Semi-Lean

Temperature (T) [oC] : 42/37/160

Density () [kg/m3] : 705.1/1133/1042

Viscosity () [Ns/m2] : 0.000012/0.0197/0.001141

Vapour Pressure (pv) [bara] : 154.6/0.425/30.64 at Temperature [oC]: 37.8

Power

Capacity (v) [m3/hr] : 2.5/0.8/0.7

Pressure Levels (ps) [bara] : (156.5-4.5) &(1.5-78)& (1.5-77.5)

Theoretical Power [kW] : none { = v( pd - ps)102 }

Pump Efficiency [-] :

Power at Shaft [kW] :

Construction Details (1)

RPM :

Drive :

Type electrical motor :

Tension [V] :

Rotational direction : Clock /

Counter Cl.

Foundation Plate : Combined /

two parts

Flexible Coupling : Yes

Pressure Gauge Suction : No

Pressure Gauge Discharge : Yes

Min. Overpressure above

pv/pm [bar] :

Nominal diameter

Suction Nozzle […] :

Discharge Nozzle […] :

Cooled Bearings : Yes / No

Cooled Stuffing Box : Yes / No

Smothering Gland : Yes / No

If yes

- Seal Liquid : Yes / No

- Splash Rings : Yes / No

- Packing Type :

- Mechanical Seal : Yes / No

- N.P.S.H. [m] :

{ = pmg }

Construction Materials (2)

Pump House :

Pump Rotor :

Shaft : Special provisions : none

Operating Pressure [bara] : 156.5/78

Wear Rings :

Shaft Box :

Test Pressure [bara] :

Remarks:

(1) Double mechanical seals and seal fluid required for LPG service. Further details to be specified by

Rotating Equipment specialist.

(2) MS = Mild Steel; HT Steel = High Tensile Steel

Designers :


Date : June 2015


EQUIPMENT NUMBER : P-102 A/B Operating : 1

NAME : High Pressure Pump Installed Spare : 1

Service : TEG solution

Type : Centrifugal

Number : 2


Pumped liquid : TEG Lean

Temperature (T) [oC] : 37

Density () [kg/m3] : 1133

Viscosity () [Ns/m2] : 0.019

Vapour Pressure (pv) [bara] : 0.425 at Temperature [oC] :37.8

Power

Capacity (v) [m3/hr] : 0.8

Suction (ps) [bara] : 78

Discharge (pd) [bara] : 156.5

Theoretical Power [kW] : 2.037 { = v( pd - ps)102 }




RPM :

Drive :


Tension [V] :


Counter Cl.


two parts





pv/pm [bar] :

Nominal diameter






If yes



- Packing Type :


- N.P.S.H. [m] :

{ = pmg }


Pump House :

Pump Rotor :


Operating Pressure [bara] : 156.5

Wear Rings :

Shaft Box :


Remarks:




Designers :


Date : June 2015



NAME : Semi-Lean Injection Pump Installed Spare : 1


Type : Centrifugal

Number : 2


Pumped liquid : Semi-Lean TEG



Viscosity () [Ns/m2] : 0.001141

Vapour Pressure (pv) [bara] : 30.64 at Temperature [oC] :37.8

Power


Suction (ps) [bara] : 1.1






RPM :

Drive :


Tension [V] :


Counter Cl.


two parts





pv/pm [bar] :

Nominal diameter






If yes



- Packing Type :


- N.P.S.H. [m] :

{ = pmg }


Pump House :

Pump Rotor :



Wear Rings :

Shaft Box :


Remarks:




Designers :


Date : June 2015



NAME : Intermediate Pump Installed Spare : 1


Type : Centrifugal

Number : 2


Pumped liquid : Semi-Lean TEG


Density () [kg/m3] : 636.3

Viscosity () [Ns/m2] : 0.00001684

Vapour Pressure (pv) [bara] : 30.64 at Temperature [oC] : 37.8

Power



Discharge (pd) [bara] : 2





RPM :

Drive :


Tension [V] :


Counter Cl.


two parts





pv/pm [bar] :

Nominal diameter






If yes



- Packing Type :


- N.P.S.H. [m] :

{ = pmg }


Pump House :

Pump Rotor :


Operating Pressure [bara] :

Wear Rings :

Shaft Box :


Remarks:




Designers :


Date : June 2015



NAME : Booster Pump Installed Spare : 1


Type : Centrifugal

Number : 2


Pumped liquid : Lean TEG Temperature (T) [

oC] : 198

Density () [kg/m3] : 969.6

Viscosity () [Ns/m2] : 0.0006234

Vapour Pressure (pv) [bara] : 0.4308 at Temperature [oC] : 37.8

Power


Suction (ps) [bara] : 1






RPM :

Drive :


Tension [V] :


Counter Cl.


two parts





pv/pm [bar] :

Nominal diameter






If yes



- Packing Type :


- N.P.S.H. [m] :

{ = pmg }


Pump House :

Pump Rotor :



Wear Rings :

Shaft Box :


Remarks:




Designers :


Date : June 2015

VACUUM PUMP – SPECIFICATION SHEET


NAME : Vacuum Pump Installed Spare : 1


Type : Roots Blower

Number : 2


Pumped liquid : Lean TEG Temperature (T) [

oC] : 150


Viscosity () [Ns/m2] : 0.000014

Vapour Pressure (pv) [bara] : at Temperature [oC] :

Power



Discharge (pd) [bara] : 1

Theoretical Power [kW] : 49 { = v( pd - ps)102 }




RPM :

Drive :


Tension [V] :


Counter Cl.


two parts





pv/pm [bar] :

Nominal diameter






If yes



- Packing Type :


- N.P.S.H. [m] :

{ = pmg }


Pump House :

Pump Rotor :


Operating Pressure [bara] : 0.02/1

Wear Rings :

Shaft Box :


Remarks:




Designers :


Date : June 2015

VESSEL – SPECIFICATION SHEET

EQUIPMENT NUMBER : V-201 In Series : 1

NAME : Flash Vessel In Parallel : none

General Data

Service : - Buffer / Storage / Separation / Reaction

Type : Vessel


- Vertical

Internals : - Demister / Plate / Coil / _________

Heating/Cooling medium : - none / Open / Closed / External Hxgr /________ - Type : n.a.

- Quantity [kg/s] : n.a.

- Press./Temp.’s [bara/oC] : n.a.

Vessel Diameter (ID) [m] : 0.46

Vessel Height [m] : 1.85

Vessel Tot. Volume [m3] : 0.31

Vessel Material : C.S.

Other :

Process Conditions

Stream Data

Feed Top Bottom

Temperature [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 42.05

: 4.5

:686

:1660

: 42.05

: 4.5

:3.86

:3.3

: 42.05

: 4.5

:1104

:1657

Composition mol% wt% mol% wt% mol% wt%

TEG

Water

Others

91.01

8.45

0.54

0

0.5

99.5

91.19

8.47

0.34

Remarks:

Designers :


Date : June 2015



NAME : Reboiler In Parallel : none

General Data


Type : Vessel


- Vertical

Internals : - Demister / Plate / Coil /Tubes

Heating/Cooling medium : - none / Open / Closed / External Hxgr /Natural Gas - Type : Fuel

- Quantity [kg/hr] : 2.66






Other :

Process Conditions

Stream Data

Feed Top Bottom

Temperature [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 150.3

: 1.1

:1012

:764.3

: 204

: 1.1

:1.104

:1.12

: 204

: 1.1

:962.4

:763.2


TEG

Water

Others

99.02

0.77

0.28

28.37

30.03

41.6

99.12

0.7

0.18

Remarks:

Designers :


Date : June 2015



NAME : Surge Vessel In Parallel : none

General Data


Type : Vessel


- Vertical

Internals : - Demister / Plate / Coil /Tubes

Heating/Cooling medium : - none / Open / Closed / External Hxgr / - Type : n.a

- Quantity [kg/hr] : n.a






Other :

Process Conditions

Stream Data

Feed Make up Bottom

Temperature [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 202.9

: 1.1

:964.2

:761

35

1

1110

24.11

: 198.0

: 2.5

:969.6

:785.2


TEG

Water

Others

99.2

0.06

0.2

99.2

0.8

0

99.2

0.06

0.2

Remarks:

Designers :


Date : June 2015

FILTER– SPECIFICATION SHEET

EQUIPMENT NUMBER : S-201A/B In Series : 1

NAME : Filter In Parallel : 1

General Data

Service : - Buffer / Storage / Separation / Reaction/Filtration

Type : Filter

Position : - Horizontal In-Line

- Vertical

- Type : Strainer

- Quantity [kg/hr] : 1657

- Press./Temp.’s [bara/oC] : 3.5/42.

Strainer Diameter (ID) [m] : 0.48

Strainer Material : S.S.

Other :

Remarks:

Designers :


Date : June 2015

PERVAPORATION MEMBRANE MODULE – SPECIFICATION SHEET

EQUIPMENT NUMBER : S-202 (1) In Series : none

NAME : Pervaporation membrane module In Parallel : 138

General Data


Type : Vessel


- Vertical

Internals : - Demister / Plate / Coil / Tubes / Membranes tubes

Heating/Cooling medium : - none / Open / Closed / External Hxgr / Natural Gas - Type : n.a

- Quantity [kg/hr] : n.a



Vessel Length [m] : 1.402


Vessel Material : S.S.

Other :

Process Conditions

Stream Data

Feed Retentate Permeate

Temperature [oC]

Pressure [bara]

Density [kg/m3]

Mass Flow [kg/hr]

: 150.3

: 3.0

: 621

: 1657

: 150.3

: 1.5

: 522

: 1529

: 150.3

: 0.02

: 1

: 128


TEG

Water

Others

91.20

8.47

0.33

98.95

0.69

0.36

-

100

-

Remarks: (1) 138 modules in rectangular disposal 14 x 10.

Then, 7 x 5 m (WxH) in the pervaporation membrane unit.

Designers :


Date : June 2015

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