methanol production

CPP MINI PROJECTTHE PRODUCTION OF METHANOL

CLB 10904 L05-T15/23/2014

Team Members: Mohd Firdaus bin Othman 55201113446 Hafidz Izzudin bin Zamri 55201113447 Ahmad Haikal bin Kastawi 55201113697 Fatin Nabihah binti Muhammad 55201113567 Hania Bamadhaj binti Omar

[CPP MINI PROJECT] May 23, 2014

55202113645 Hanis Nadhirah binti Omar 55201113518

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1.0 Table of Content

CONTENTS PAGE2.0 Executive Summary 23.0 Introduction 44.0 Process Description

4.1 Common Methods of Methanol Production4.2 Advantages and Disadvantage of Lurgi and Haldor-Topsoe Process4.3 Process Selected4.4 Process Condition

101420

2223

5.0 Physical and Chemical Properties5.1.1 Physical Properties of Methanol5.1.2 Chemical Properties of Methanol5.2.1 Physical Properties of Carbon Monoxide5.2.2 Chemical Properties of Carbon Monoxide5.3.1 Physical Properties of Water5.3.2 Chemical Properties of Water5.4.1 Physical Properties of Nitrogen5.4.2 Chemical Properties of Nitrogen5.5.1 Physical Properties of Methane5.5.2 Chemical Properties of Methane5.6.1 Physical Properties of Ethane5.6.2 Chemical Properties of Ethane5.7.1 Physical Properties of Hydrogen5.7.2 Chemical Properties of Hydrogen5.8.1 Physical Properties of Carbon Dioxide5.8.2 Physical Properties of Carbon Dioxide

2626283133343641424344454749505152

6.0 Material and Energy Balance6.1 Mass Balance

ReformerSulphur RemoverReactor

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Refining Column6.2 Energy Balance

Reactive Process : Reformer : Reactor

REFERENCES

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2.0 Executive Summary

Our study on the production of methanol has shown us that

the use of methanol in fuel applications is expected to have a

big impact on future demand. Methanol can be used in biodiesel

production where it is used in the trans-esterification step of

the process. Despite having a large number of biodiesel plants

being built instability in the biodiesel industry has been

detected. From all the countries actively producing methanol, it

has been found that China is the largest regional market for

methanol and the main driver of global markets. They are

experiencing a period of active growth of demand for methanol.

The production capacity growth changes the situation on the world

market. Methanol is increasingly being used to make DME. The

study on the main indicators of Chinese methanol market in 2003-

2006 (IRUE, 2008) shows that in production, from 2003-2006, the

number shows an increase 2989 to 5764 while in the consumption

department, and the number shows an increase from 4340 in 2003

and 6745 in 2006. At the import department, the number decreases

from 1402 to 920, while in the export department it shows an

instability from 51 in 2003, 33 in 2004 and the number goes back

up to 55 and 57 in 2005 and 2006 respectively. The share of

import in consumption shows a decrease from 32% t0 13.6% from

2003 to 2006.

China is also investigating methanol-to-gasoline (MTG)

technology which was first developed in the 1980s but at the time[Type text] Page 4


proved to be uneconomic. However, fuel cells are being used in

forklift trucks and military applications (Jim Jordan and

Associates, 2010).

In the US, methanol's future may have a place in US gasoline and

transportation, given its similar properties to renewable fuel

ethanol. But analysts say methanol has similar advantages and

disadvantages to ethanol.

Methanol and sodium chlorate are used to produce chlorine

dioxide, a bleaching agent for the pulp and paper industry.

Glycol ethers are solvents used in acrylic coatings and newer

high-solids and waterborne coatings. Methyl mercaptan is used an

intermediate in the production of DL-methionine, an amino acid

supplement in animal feeds (Jim Jordan and Associates, 2010).

On to the actual production of methanol, first and foremost,

the initial stage of methanol production is Feed Purification.

The two main feed stocks which are natural gas and water are

requiring to purification before use. Natural gas contains low

levels of sulphur compounds and undergoes a desulphurization

process. Next, Reforming is the next stage of the methanol

manufacturing process and basically it is the process of natural

gas is combined with steam under heat to produce synthesis gas.

The third stage is Compression and Conversion of methanol

manufacturing process whereby the synthesis that have been

synthesis is pressurized (compressed) and reacted (converted) to

form methanol. On to the fourth stage which is Distillation. The

liquid mixture is heated to separate the components and the

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resulting vapour is cooled and condensed to produce pure

methanol. This is the last stage in the production of methanol.

The processes used and applied in the production of

methanol are the Haldor-Topsoe Process and the Lurgi Process.

Haldor-topsoe process is a typical process of large scale

methanol manufacturing that has been used in many plants. A

common Haldor-Topsoe methanol design includes this main which are

feed purification which is the desulphurisation of the

hydrocarbon feedstock, reforming which is to reach the optimum

synthesis of gas module, synthesis which is the methanol

synthesis in adiabatic reactors and distillation. For the Lurgi

process, the main process features to achieve these goals are by

using oxygen-blown natural gas reforming, either in combination

with steam reforming or as pure auto thermal reforming. Next is

by using two-step methanol synthesis in water and gas that cooled

in reactors and it is operating by the optimum reaction route.

Lastly is the adjustment of syngas composition by hydrogen

recycling. After the advantages and disadvantages of both

processes have been evaluated, the process chosen was Haldor

Topsoe which is more likely favourable to choose rather than

Lurgi process due to some reasons of the selection process

itself. The typical process conditions that necessary for the

Haldor-Topsoe design is based on three specifications which are

the temperature, pressure and inlet compositions. It is based on

instruments that are used.

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3.0 INTRODUCTION

In order to establish the feasibility of the project, a

study of the history of the methanol market over the last decade

is presented in a global perspective. The size and nature of the

market is studied, including the determination of general trends

in industry and potential growth areas. The limitations of

looking at the history of any industry are recognized, however,

the value of such an exercise should not be underestimated. This

background, and knowledge of the broader spectrum of the

prevailing domestic economic climate, improves the potential for

more reliable decision making. The potential market size and its

location, and the required product quality are all determined

from this study (Ray, Martyn S., 1949). The use of methanol in

fuel applications is expected to have a big impact on future

demand. Methanol can be used in biodiesel production where it is

used in the trans-esterification step of the process. While a

large number of biodiesel plants have been built, there has been

uncertainty in the biodiesel industry.

Over last five years, Asian methanol market is actively

developed. China is the largest regional market for methanol and

the main driver of global markets. They have seen double-digit

growth in methanol demand with strong performances in the acetic

acid, methanol blending in gasoline and DME sectors (IRUE, 2008).

They are experiencing a period of unprecedented growth of demand

for methanol and methanol production capacity growth that changes[Type text] Page 8


the situation on the world market. Methanol is increasingly being

used to make DME, which can be employed as an alternative to

diesel, a supplement to liquefied petroleum gas (LPG) and in

power generation. The largest DME market is China where it is

blended into LPG. The DME industry in China is suffering from

overcapacity (Jim Jordan and Associates, 2010).

2003 2004 2005 2006Production 2989 4406 5356 5764Consumption 4340 5732 6662 6741Import 1402 1359 1360 920Export 51 33 55 57Share of Import in

consumption

32% 24% 20% 13,6

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Figure 1: Main indicators of Chinese methanol market in 2003-2006

(IRUE, 2008)

(Source: CCR, CMAI)

Figure 2: Geographical structure of China’s import of

methanol (IRUE, 2008)

(Source: IRUE "National center of marketing and price study")

Company Capacity, tons

/year

Raw materials

Hebei Qianan Chem Co 800 000 Coal

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Hong Kong Zhongyi Co 2 000 000 *Inner Mongolia Ximeng Group Co 1 200 000Yongcheng Coal & Electricity Group

Co

500 000 Coal

Xinjiang Petroleum Bureau 200 000 *Qinghai Zhonghao Natural Gas

Chemical Co

600 000 Natural gas

Shanxi Coking Co 300 000 CoalYankuang Group 500 000 *Inner Mongolia Boyuan United Chem

Co

1 000 000 *

Jiutai Energy (Inner Mongolia) Co 1 500 000 *Shandong Yanzhou Coal Mining Co 400 000 CoalQinghai Oilfield Germu Refinery 300 000 *Henan Zhongyuan 400 000 Natural gasShanghai Coking & Chemical Co 400 000 CoalYunnan Petroleum & Chemical

Industry Group Co

300 000 *

Huating Zhongxu Coal Chemical Co

Ltd

600 000 *

Inner Mongolia Xiyang Coal

Chemical Co

400 000 Coal

Erdos Rongcheng Energy Chemical Co 1 000 000 *Lanzhou Blue Star Chemical Co 200 000 *

Table 1: Projects for the development of methanol production in

China (IRUE, 2008)[Type text] Page 11


* under construction, planned or proposed

(http://www.export.by/en/?

act=s_docs&mode=view&id=2408&type=&mode2=archive&doc=64)

China is also investigating methanol-to-gasoline (MTG)

technology which was first developed in the 1980s but at the time

proved to be uneconomic. Jincheng Anthracite Mining Group (JAMG)

has been operating a coal-based 100,000 tonne/year plant since

June 2009 in Shanxi province. JAMG has plans to increase coal-

based gasoline production to 1M tonne/year. Methanol can also be

considered as an alternative to diesel for electricity generation

in small communities where the cost of LNG facilities is too

high. Methanol Holdings Trinidad (MHTL) and the University of

Trinidad and Tobago have developed an 8.5 MW methanol-fed power

plant that is providing electricity for MHTL’s production site in

Trinidad. Fuel cells based on methanol were first targeted

unsuccessfully at automotive applications but early applications

have been in portable power generation. Cell phones and laptop

computers had also been seen as potential applications for

methanol fuel cells but this has yet to happen. However, fuel

cells are being used in forklift trucks and military applications

(Jim Jordan and Associates, 2010).

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http://www.export.by/en/?act=s_docs&mode=view&id=2408&type=&mode2=archive&doc=64

http://www.export.by/en/?act=s_docs&mode=view&id=2408&type=&mode2=archive&doc=64


In the US, methanol's future may have a place in US gasoline

and transportation, given its similar properties to renewable

fuel ethanol. But analysts say methanol has similar advantages

and disadvantages to ethanol. Another hurdle is that US car

engines would need to be converted on a mass scale to run on

methanol. Latin America is a primary supplier to North America,

with significant volumes to Europe as well. The region has

approximately 11.6m tonne/year of capacity. The major supply

points are Trinidad, with approximately 6.6m tonne/year of

capacity; Venezuela, with 2.4m tonne/year; and Chile, with

approximately 1.8m tonne/year of effective capacity. Demand

growth in Europe is at GDP levels. No investment is expected in

Western Europe, with plans for new capacity focused in Russia,

although some projects have been delayed or postponed. Global

oversupply is likely to force rationalisation of uneconomic

plants, particularly if prices remain under pressure (Jim Jordan

and Associates, 2010).

Asia methanol prices were at around $350/tonne CFR (cost &

freight) NE Asia (northeast Asia)/SE Asia (Southeast Asia) in

mid-February, before falling to a low of around $335- 45/tonne

CFR NE Asia/SE Asia in mid-March. Chinese electronic futures

pricing had decreased, leading to a bearish buying sentiment for

physical cargoes. Buying activity from the downstream dimethyl

ether (DME) sector in China was also subdued, as DME demand was

dampened by dwindling liquefied petroleum gas (LPG) prices.

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Inventories in China were still high, at around half a million

tonnes. The cheaper domestic cargoes similarly put a halt to most

spot buying activity. However prices picked up slightly in late

March, ending at around $345-360/tonne CFR NE Asia/SE Asia in

mid-May. It was suggested that higher crude prices would result

in greater levels of methanol blending in gasoline in China,

propping up LPG prices and hence DME demand, as well as boosting

Chinese methanol demand. In India, however, prices declined in

response to weak sentiment, falling from around $340/tonne CFR to

around $320/tonne CFR, because of excessive inventories. Prices

picked up slightly in late March on the back of sronger

formaldehyde demand (ICIS, 2011).

The three largest derivatives of methanol are formaldehyde,

methyl tertiary butyl ether (MTBE) and acetic acid. However,

methanol is seeing growing demand in fuel applications such as

dimethyl ether (DME), biodiesel and the direct blending into

gasoline. Formaldehyde is used mainly to make amino and phenolic

resins which are employed in the manufacture of wood-based

products such as panels, flooring and furniture. In North America

and Western Europe, these are mature markets for formaldehyde

with GDP related growth but above average growth have been

experienced in Eastern Europe and Asia, particularly China. The

main use for MTBE is an octane booster and oxygenate in gasoline.

However, it has been phased out in the US following its

contamination of underground water supplies and the removal of

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the oxygenate mandate and liability protection (Jim Jordan and

Associates, 2010). In Europe, some MTBE has been replaced by ethyl tertiary

butyl ether (ETBE) manufactured from bioethanol to take advantage

of the biofuels subsidies although some producers have the

flexibility to switch between the two products according to

market conditions. However, there is growth in MTBE consumption

in Asia and the Middle East, driven by the need to reduce air

pollution. According to LyondellBasell, MTBE will continue to be

vital for fuel quality and cleaner emissions. As countries look

to remove sulphur and lead and reduce aromatic content in the

gasoline pool, MTBE will make a significant contribution to

improve fuel quality (Jim Jordan and Associates, 2010).

Acetic acid has a number of outlets of which the two largest

are vinyl acetate monomer (VAM) and purified terephthalic acid

(PTA). Global demand for acetic acid has been growing at a steady

4%/year with PTA sector growth at double this rate driven by

polyester demand. In the area of petrochemical feedstocks, there

has been considerable interest in methanol-to-olefins (MTO) and

methanol-to-propylene (MTP) technologies with projects underway

in China. The first MTO unit in China was started up in August

2010 by Shenhua Baotou Coal Chemical. The complex includes a 1.8m

tonne/year coal-based methanol unit, a 600,000 tonne/year MTO

facility, a 300,000 tonne/year polyethylene (PE) plant and a

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300,000 tonne/year polypropylene (PP) plant (Jim Jordan and

Associates, 2010). Two plants producing propylene from coal are under

construction. The facility being built by Shenhua Ningxia Coal

Industry Group in Ningxia province is expected to begin

commercial production in early 2011. It can produce 470,000

tonne/year of propylene and 500,000 tonne/year of PP. A number of

other projects are in the planning stage but there is concern

about overcapacity in coal-to-chemicals projects in China.

Methanol is also used for the basis of many other chemical

products.

i. The largest solvent use for methanol is as a component

of windscreen wash antifreeze. It can also be used to

extract, wash, dry and crystallise pharmaceutical and

agricultural chemicals.

ii. Methylamines are used as intermediates in a range of

speciality chemicals with applications in water

treatment chemicals, shampoos, liquid detergents and

animal feeds.

iii. Methyl methacrylate (MMA) is employed in the production

of acrylic polymers.

iv. Dimethyl terephthalate (DMT) is used to make polyesters

although PTA is the preferred feedstock.

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Methanol and sodium chlorate are used to produce chlorine

dioxide, a bleaching agent for the pulp and paper industry.

Glycol ethers are solvents used in acrylic coatings and newer

high-solids and waterborne coatings. Methyl mercaptan is used an

intermediate in the production of DL-methionine, an amino acid

supplement in animal feeds (Jim Jordan and Associates, 2010).

4.0 PROCESS DESCRIPTION

4.1 INTRODUCTION

There are four main stages of basic methanol production that

operate continuously 24 hours a day in the plants which is Feed

Purification, Reforming, Compression and Conversion and

Distillation. Here, the common processes of methanol production

are Lurgi Process and Haldor-topsoe Process will be presented.

The first stage of methanol production is Feed Purification.

The two main feed stocks which are natural gas and water are

requiring to purification before use. Natural gas contains low

levels of sulphur compounds and undergoes a desulphurization

process. It is to reduces sulphur to levels of less than one part

per million. The impurities in the water are reduced to

undetectable before it’s being converted to the steam and added

to the process. If there are not removed, these impurities can

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result in reduced heat efficiency and significant damage to major

pieces of equipment.

Typical Composition of Natural Gas

Methane CH4 70 - 90%

Ethane C2H6

0 - 20%Propane C3H8

Butane C4H10

Carbon Dioxide CO2 0 - 8%

Oxygen O2 0 - 0.2%

Nitrogen N2 0 - 5%

Hydrogen Sulphide H2S 0 - 5%

Rare gases Ar, He, Ne Xe trace

Reforming is the next stage of the methanol manufacturing

process. It is the process of natural gas is combined with steam

under heat to produce synthesis gas, which consists of hydrogen,H2 , Carbon monoxide, CO and carbon dioxide, CO2. The process is

to transform the methane (CH4) and the steam water (H2O) to

intermediate reactants of hydrogen (H2), carbon dioxide (CO2),

carbon monoxide (CO). carbon ioxide is also added to the feed

gas stream to produce a mixture of components in the ideal ratio

to the efficiently produce methanol.

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Figure 3 : Reforming of methanol production

The third stage is Compression and Conversion of methanol

manufacturing process. It is where the synthesis that have been

synthesis is pressurized (compressed) and reacted (converted) to

form methanol. Aftre removing the excess heat from the reformed

gas, it is compressed before being sent to the methanol

production stage in the synthesis reactor. The reactants are

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converted methanol and separated out as crude product with a

composition of methanol (68%) and water (31%). Methanol

conversion is at a rate about 5% per pass. Hence , there is a

continual recycling of the unreacted gases in the synthesis loop.

This continuouously process however results in a form of inert

gases in the system and this is continuously purged and sent to

the reformer where it is burnt as fuel. The crude methanol formed

is condensed and sent to the methanol purification step which is

the final stage in the process.

Figure 4 : Compression and conversion of methanol production

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Distillation is a fourth stage where the liquid mixture is

heated to separate the components and the resulting vapour is

cooled and condensed to produce pure methanol. About 68% methanol

solution is purified in two distinct steps in tall distillation

columns called the topping column and refining column to yield a

refined product with a purity of 99.99% methanol classified as

grade AA refined methanol.

Figure 5 : Distillation of Methanol production

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4.1 COMMON METHODS OF METHANOL PRODUCTION

4.1.1 HALDOR-TOPSOE PROCESS

Haldor-topsoe process is a typical process of large scale

methanol manufacturing that has been used in many plants. A

common Haldor-Topsoe methanol design includes this main which are

feed purification: desulphurisation of the hydrocarbon

feedstock

reforming: advanced tubular reforming, two-step oxygen fired

reforming, auto thermal reforming or heat exchange reforming

– selected to reach the optimum synthesis gas module

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synthesis: methanol synthesis in adiabatic reactors or

boiling water reactors

distillation: in single, two- or three-column design

Feed purification

It is the process that used to expel impurities such as sulphur

and chlorine effectively from hydrocarbon feed. It is to avoid

poisoning of nickel-based catalyst that has been used in the

various reforming technologist and other downstream catalysts.

Haldor-topsoe’s feed purification catalysts range provides low

cost removal of sulphur and chlorine compounds from hydrocarbon

feedstock ranging from natural gas to naphtha.

Reforming

Advanced tubular reforming in topsoe’s reformer design is based on the

side-fired furnace concept which is ensures high alloy tube

materials and maximum average heat flux. Accurate temperature

control and an even heat flux ensures long lifetime of the tubes

of reformer. The ratio of carbon to hydrogen in the feedstock

will determine the composition of the synthesis gas. It can only

be adjusted within narrow range. Usually, a typical natural gas

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will be produced a sulplus of hydrogen about 40% when it is

compared to the stoichiometric composition. The hydrogen is

carried an inert gas synthesis process.

Two-step oxygen-fired reforming is a combination of tubular reforming

and oxygen-fired auto thermal reforming (ATR). This process is

produces a synthesis gas with a composition which is optimal for

the methanol synthesis. The hydrogen and carbon oxides close to

the stoichiometric are not only the one which is required the

ratio but also a low concentration of methane is achieved thanks

to the relatively high temperature at outlet of the ATR. The ATR

makes it possible to operate the primary reformer with a leakage

of unconverted methane. The tubular reformer can operate at much

less demanding conditions, lower temperature and higher pressure

compared to the one-step reforming process. These operating

conditions lead to a reduction in the reformer tube weight about

75 to 80% compared to one-step tubular reforming.

Stand-alone auto thermal reforming is the solution of particular

interest in large methanol plants because of the air separation

unit and the ATR will benefit more from economy of scale than the

tubular reformer.

Synthesis

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In the synthesis of methanol section, the synthesis gas is

converted to raw methanol that containing small amounts of water

and by products. The topsoe’s methanol technology offers an

optimum combination of process steps, achieving attractive

operation costs and competitive installation costs. The boiling

water reactor is most widely used in order to its efficiency and

ease of temperature control. Adiabatic reactors in series or

combinations of boiling water reactor (BWR) and adiabatic

reactors also are considered.

Distillation

Water and by-products are removed from the raw methanol in the

distillation section, which is most used designed for methanol

production in order to American Federal Grade AA. The key issues

to be considered are a low energy consumption and operational

stability. Designs include single-, two- or three-column

distillation units.

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4.1.2 LURGI PROCESS

Lurgi’s Process is another common one that used in methanol

production. This is an advanced and efficiencies technology for

converting the natural gas to form methanol in large quantities.

The Lurgi MegaMethanol technology has been developed for world-

scale methanol plants with capacities which are greater than one

million metric tons per year. In order to achieve such capacity,

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an advanced design, cost optimised energy efficiency, low

environmental impact and low cost of investment are needed.

The main process features to achieve these goals are by

using oxygen-blown natural gas reforming, either in combination

with steam reforming or as pure auto thermal reforming. Next is

by using two-step methanol synthesis in water and gas that cooled

in reactors and it is operating by the optimum reaction route.

Lastly is the adjustment of syngas composition by hydrogen

recycling.

Synthesis gas production

The configuration of the reforming process mainly due to the

feedstock composition which is has varied from light natural gas

to oil-associated gases.

Reforming

Combined reforming process is for heavy natural gases and oil-

associated gases, the required stoichiometric number cannot be

obtained by pure auto thermal reforming, even if all of hydrogen

available to recycle. After desulphurization process, a feed gas

branch stream is decomposed in a steam reformer at high pressure

at about 35-40 bar and in low temperature at about 700-800Cᴼ.

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Then the reformed gases are mixed to the remainder feed gas and

reformed to syngas at high pressure in the auto thermal reactor.

The auto thermal reforming is when in syngas production, pure auto

thermal reforming are applied whenever light natural gas is

available as feed-stock to the process. The desulfurized and

optional pre-formed feedstock is reformed with steam in order to

synthesis gas about 40 bar and higher using oxygen as reforming

agent. Carbon-free synthesis gases are generated in this process

and its offers advance operating flexibility over a wide range to

meet specific requirements. The range temperatures in reformer

outlet are usually in the range of 950-1050Cᴼ. Next, the

synthesis gas is compressed in a single gas.

Synthesis

The Lurgi Methanol reactor is usually a vertical shell and tube

heat exchanger with fixed tube sheets. In the tubes, the catalyst

is accommodated and rests is the inert material. Heat of reaction

is taken off below upper tube sheet in order to generate the

water mixture. Steam pressure and reaction temperature are under

the control permits. In the first reactor which is isothermal

reactor is accomplishes partial conversion of the syngas to

methanol at higher space velocities and higher temperatures

compared with single-stage synthesis reactor. The methanol are

containing the gas are going to the second downstream reactor

without prior cooling. In this second reactor, cold feed gas is

routed through tubes in a counter current flow with the reacting

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gas. The reaction temperature is continuously reduced over the

reaction path in the second reactor. After cooling and separation

of the purge gas, the crude methanol is process in distillation.

Distillation

The crude methanol is purified in an energy-saving 3-column

distillation unit. The low boilers are removed in the pre-un

column and the higher boiling components are separated in two

methanol columns. The first pure methanol column is used to

operate at elevated pressure and the second column at atmospheric

pressure.

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4.2 ADVANTAGES AND DISADVANTAGES OF LURGI AND HALDOR TOPSOE

PROCESSES

4.2.1 LURGI PROCESS

i) Based on auto thermal reforming of natural gas or oil

associated gas which involves in the high CO selectivity

and low CO2 production besides having a multilayer

refractory lining which gives thermal protection

ii) Capacities goes up from 2.46x1012 to 3.65x1012 ton/yr

iii) Having such higher energy efficiency

iv) Reducing (20%-30%) of investment compared to conventional

steam reforming

v) Higher flexibility towards feedstock fluctuations

vi) High reliability and gasification efficiency and low oxygen

consumption

vii) Installation cost is US $350 000

viii) The bad thing about this process is its complex and it

has high capital cost

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4.2.2 HALDOR TOPSOE PROCESS

i) Low energy consumption for recycle used to control the

temperature rise in the first methanation reactor

ii) Production of high pressure superheated steam which

involves such low investments

iii) The design of the methanol synthesis section is essential

to ensure low investment of the process

iv) Producing a natural gas compatible with pipeline

specification ensuring an easy access to distribution of

the product

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v) Good for low capacity process and capital cost

vi) Stable and operatable at low as well as high temperature

( from 250 to 700’C)

vii) Easy to operate as it is based on steam reforming

viii) Having such low catalyst cost compared to lurgi process

ix) Both process work on low pressure

x) Produces a synthesis gas well suited for production of

both fuel grade and high purity methanol

xi) Elimination of expensive heat exchanger required in

process operated at low pressure

xii) The disadvantage of this process is that it has shorter

life of converters besides having such high apparatus

unkeep in the high pressure operation

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4.3 PROCESS SELECTED: HALDOR TOPSOE PROCESS

Based on the advantages and disadvantages stated, we finally

come to the point whereby Haldor Topsoe is more likely favourable

to choose rather than Lurgi process due to some reasons of the

selection process itself.

Firstly it is due to its great technology which offers an

optimum combination of process steps, achieving attractive

operation costs and competitive installation costs. Greater

compactness and simplicity in case of converter design since high

under pressure gasses have smaller volume is also one of the god

reasons why we chose Haldor Topsoe process itself. Haldor Topsoe

process also operates at the pressures lower than Lurgi and

against the disadvantage of using heat exchange for heat recovery

and less compactness in converter design.

Recovery of 20% of unconverted gas and recycling it to

increase the efficiency and conversion of complete process and

the large and massive compressors which are used in Lurgi process

are required to maintaining 900 atm which sost millions of

dollars are avoided in Haldor Topsoe and is thus more economic,

having such low capital cost and good especially for large

capacity process. Besides that, it launched the Collect Mix

Distribute (CMD) concept which ensures cross mixing of the gas

from the upper bed through mixing with the quench gas and even

distribution of the mixed gas to the next bed, thereby using the

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catalyst more efficiently in a low catalyst cost compared to

Lurgi.

The effective design of the methanol synthesis section is

essential to low to ensure low investment of the process which

result in superior activity, selectivity and operational

flexibility at the entire range of the synthesis gas compositions

accompanied with very high conversion efficiency throughout the

catalyst lifetime which prolonged service time due to the high

stability of the catalyst. The elimination of the intermediate

production and storage of methanol for integrated methanol

reaction to form DME immediately improved conversion efficiency

that reduces steam consumption in the CO2 removal as module

adjustment may be carried out inside the synthesis loop,

minimising the recycle unconverted synthesis gas which is

efficient production of high quality gasoline for ready blending

compared to Lurgi.

4.4 PROCESS CONDITION OF SELECTED METHOD

The typical process conditions that necessary for the

Haldor-Topsoe design is based on three specifications. It is

based on instruments that are used.

I. Temperature

II. Pressure

III. Inlet compositions

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4.4.1 CHEMMICAL COMPOSITION AND CONDITIONS AT INLET

INSTRUMENT INLET REACTANT

COMPOSITION

Temperature

(ᴼC)

Pressur

e

(bar)

SULPHUR REMOVAL 0.92 CH4,

0.03 S,

0.05 N2

50 70

REFORMER 1 CH4 50 70

1 H2O 30 1

REACTOR 0.13CH4,

0.05 H2O,

0.15 CO,

0.05 CO2,

0.062 H2

250 54

REFINING COLUMN 0.2CH4,

0.13 H2O,

0.01 CO,

0.016 CO2,

0.37H2,

0.274CH3OH

270 54

[Type text] Page 35


4.4.2 CHEMMICAL COMPOSITION AND CONDITIONS AT OUTLET

INSTRUMENT OUTLET REACTANT

COMPOSITION

Temperature

(ᴼC)

Pressure

(bar)

SULPHUR

REMOVAL

0.37 S

0.63 N2

50 70

REFORMER 0.13CH4,

0.05 H2O,

0.15 CO,

0.05 CO2,

0.062 H2

250 54

REACTOR 0.2CH4,

0.13 H2O,

0.01 CO,

0.016 CO2,

0.37H2,

0.274CH3OH

270 54

REFINING

COLUMN0.67 CH3OH,

0.33 H2O

25 1

0.33CH4,

0.022 CO,

0.026 CO2,

0.622H2

25 1

[Type text] Page 36


[Type text] Page 37


4.4.3 Flowdiagram of selected process

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5.0 Physical and chemical properties

5.1 Methanol

5.1.1 Physical properties of methanol

Also called METHYL ALCOHOL, it is the simplest of a long series

of organic compounds called alcohols; its molecular formula is

CH3OH. The modern method of preparing methanol is based on the

direct combination of carbon monoxide gas and hydrogen in the

presence of a catalyst at elevated temperatures and pressures.

Most methanols are produced from the methane component of natural

gas.

Pure methanol is an important material in chemical

synthesis. Its derivatives are used in great quantities for

building up a vast number of compounds, among them many important

synthetic dyestuffs, resins, drugs, and perfumes. Large

quantities are converted to dimethylaniline for dyestuffs and to

formaldehyde for synthetic resins. It is also used in automotive

antifreezes, in rocket fuels, and as a general solvent. Methanol

is also a high-octane, clean-burning fuel that is a potentially

important substitute for gasoline in automotive vehicles.

Methanol is a colourless liquid, completely miscible with

water and organic solvents and is very hygroscopic. It boils at

64.96° C (148.93° F) and solidifies at -93.9° C (-137° F). It

[Type text] Page 39


forms explosive mixtures with air and burns with a nonluminous

flame. It is a violent poison; drinking mixtures containing

methanol has caused many cases of blindness or death. Methanol

has a settled odour. Methanol is a potent nerve poison.

Key physical properties are:

Molecular Weight 32.04

Boiling Point 64.7CMelting Point -97.8CFlash Point 12C (54F) closed cupAuto ignition Temperature 878FVapour Pressure 92 mm Hg at 20CDensity/Specific Gravity 0.7915 at 20/4 C (water =

1)Vapour Density 1.11 (air = 1)Log/Octanol Water Partition

Coefficient

-0.77

Conversion Factor 1 ppm = 1.31 mg/m3 at 25C

[Type text] Page 40


5.1.2 Chemical properties of methanol

Combustion of Methanol:

Methanol burns with a pale-blue, non-luminous flame to form

carbon dioxide and steam.

2CH3OH + 302 ===> 2CO2 + 4H2O

Oxidation of Methanol:

[Type text] Page 41


Methanol is oxidized with acidified Potassium Dichromate, K2Cr2O7,

or with acidified Sodium Dichromate, Na2Cr2O7, or with acidified

Potassium Permanganate, KMnO4, to form formaldehyde.

[O]

CH3OH ===> HCHO + H2

Methanol Formaldehyde

2H2 + O2 ===> 2H2O

If the oxidizing agent is in excess, the formaldehyde is further

oxidized to formic acid and then to carbon dioxide and water.

[O] [O]

HCHO ===> HCOOH ===> CO2 + H2O

Formaldehyde

Formic

Acid

Catalytic Oxidation of Methanol:

The catalytic oxidation of methanol using platinum wire is of

interest as it is used in model aircraft engines to replace the

sparking plug arrangement of the conventional petrol engine. The

heat of reaction is sufficient to spark the engine.

Dehydrogenation of Methanol:

[Type text] Page 42


Methanol can also be oxidized to formaldehyde by passing its

vapor over copper heated to 300 °C. Two atoms of hydrogen are

eliminated from each molecule to form hydrogen gas and hence this

process is termed dehydrogenation.

Cu

300°C

CH3OH ===> HCHO + H2

Methanol Formaldehyde

Dehydration of Methanol:

Methanol does not undergo dehydration reactions. Instead, in

reaction with sulphuric acid the ester, dimethyl sulphate is

formed.

concentrated

H2SO4

2 CH3OH ===> (CH3)2SO4 + H2O

Methanol Dimethyl

Water

Sulphate

Esterification of Methanol

Methanol reacts with organic acids to form esters.

H(+)

CH3OH + HCOOH ===> HCOOCH3 + H2O

[Type text] Page 43


Methanol Formic

Methyl Water

Acid Formate

Substitution of Methanol with Sodium

Methanol reacts with sodium at room temperature to liberate

hydrogen. This reaction is similar to the reaction of sodium with

ethanol.

2 CH3OH + 2 Na ===> 2CH3ONa + H2

Methanol Sodium Sodium

Hydrogen

Methoxide

Substitution of Methanol with Phosphorus Pentachloride

Methanol reacts with phosphorus pentachloride at room temperature

to form hydrogen chloride, methyl chloride, (i.e. chloroethane)

and phosphoryl chloride.

CH3OH + PCl5 ===> HCl +

CH3Cl + POCl3

Methanol Phosphorus Hydrogen

Methyl Phosphoryl

[Type text] Page 44


Pentachloride Chloride

Chloride Chloride

Substitution of Methanol with Hydrogen Chloride

Methanol reacts with hydrogen chloride to form methyl chloride

(i.e. chloromethane) and water. A dehydrating agent (e.g. zinc

chloride) is used.

ZnCl2

CH3OH + HCl ===> CH3Cl +

H2O

Methanol

Methyl

Chloride

[Type text] Page 45


5.2 Carbon Monoxide

5.2.1 Physical properties of carbon monoxide

Carbon monoxide (CO) is a tasteless, odourless, colourless,

noncorrosive and quite stable diatomic molecule that exists as a

gas in the Earth’s atmosphere. Radiation in the visible and near-

ultraviolet (UV) regions of the electromagnetic spectrum is not

absorbed by carbon monoxide, although the molecule does have weak

absorption bands between 125 and 155 nm. Carbon monoxide absorbs

radiation in the infrared region corresponding to the vibrational

excitation of its electronic ground state. It has a low electric

dipole moment (0.10 debye), short interatomic distance (0.123 nm)

and high heat of formation from atoms or bond strength (2072

kJ/mol). These observations suggest that the molecule is a

resonance hybrid of three structures (Perry et al., 1977), all of

which contribute nearly equally to the normal ground state.


Specific Gravity 0.967

Specific Volume (ft3/lb, m3/kg) 14.0, 0.874

Absolute Viscosity (lbm/ft s, centipoises) 12.1 10-6,

0.018

Sound velocity in gas (m/s) 352

[Type text] Page 46


Specific Heat - cp - (Btu/lboF or cal/goC, J/kgK) 0.25, 1046

Specific Heat Ratio - cp/cv 1.40

Gas constant - R - (ft lb/lboR, J/kgoC) 55.2, 297

Thermal Conductivity (Btu/hr ft oF, W/moC) 0.014, 0.024

Boiling Point - saturation pressure 14.7 psia

and 760 mm Hg - (oF, oC)

-312.7, -191.5

Latent Heat of Evaporation at boiling point

(Btu/lb, J/kg)

92.8, 216000

Freezing or Melting Point at 1 atm (oF, oC) -337, -205

Latent Heat of Fusion (Btu/lb, J/kg) 12.8

Critical Temperature (oF, oC) -220, -140

Critical Pressure (psia, MN/m2) 507, 3.49

Critical Volume (ft3/lb, m3/kg) 0.053, 0.0033

Flammable Yes

Heat of combustion (Btu/ft3, Btu/lb, kJ/kg) 310, 4340,

10100

[Type text] Page 47


5.2.2 Chemical properties of carbon monoxide

Carbon monoxide is so fundamentally important that many methods

have been developed for its production. Producer gas is formed

by combustion of carbon in oxygen at high temperatures when there

is an excess of carbon. In an oven, air is passed through a bed

of coke. The initially produced CO2 equilibrates with the

remaining hot carbon to give CO. The reaction of O2 with carbon

to give CO is described as the Boudouard equilibrium. Above 800

°C, CO is the predominant product:

O2 + 2 C → 2 CO

The downside of this method is if done with air it leaves a

mixture that is mostly nitrogen.

Synthesis gas or Water gas is produced via the endothermic

reaction of steam and carbon:

H2O + C → H2 + CO

CO also is a by-product of the reduction of metal oxide ores with

carbon, shown in a simplified form as follows:

MO + C → M + CO

Since CO is a gas, the reduction process can be driven by

heating, exploiting the positive (favourable) entropy of

reaction. The Ellingham show that CO formation is favoured over

CO in high temperatures.CO is the anhydride of formic acid. As

such it is conveniently produced by the dehydration of formic

[Type text] Page 48


acid, for example with sulphuric acid. Another laboratory

preparation for carbon monoxide entails heating an intimate

mixture of powdered zinc metal and calcium carbonate.

Zn + CaCO3 → ZnO + CaO + CO

Another lab style of generate CO is reacting Sucrose and Sodium

Hydroxide in a closed system.

5.3 Water

5.3.1 Physical properties of water

Water is the chemical substance with chemical formula H2O, one

molecule of water has two hydrogen atoms covalently bonded to a

single oxygen atom. Water appears in nature in all three common

states of matter and may take many different forms on

Earth: water vapour and clouds in the sky; seawater and icebergs

in the polar oceans; glaciers and rivers in the mountains; and

the liquid in aquifers in the ground. At high temperatures and

pressures, such as in the interior of giant planets, it is argued

that water exists as ionic water in which the molecules break

down into a soup of hydrogen and oxygen ions, and at even higher

pressures as super ionic water in which the oxygen crystallises

[Type text] Page 49

http://www.62.co.za/importance.html







but the hydrogen ions float around freely within the oxygen

lattice.

Properties ValueMolar mass 18.015Molar Volume 55.5 moles/literBoiling Point (BP) 100°C at 1 atmFreezing point (FP) 0°C at 1 atmTriple point 273.16 K at 4.6 torrSurface Tension 73 dynes/cm at 20°C[Type text] Page 50


Vapour pressure 0.0212 atm at 20°CHeat of vaporization 40.63 kJ/molHeat of Fusion 6.013 kJ/molHeat Capacity (cp) 4.22 kJ/kg.KDielectric Constant 78.54 at 25°CViscosity 1.002 centipoise at 20°CDensity 1 g/ccDensity maxima 4°CSpecific heat 4180 J kg-1 K-1 ( T=293…373 K)Heat conductivity 0.60 W m-1 K-1 (T=293 K)Melting heat 3.34 x 105 J/kgEvaporation heat 22.6 x 105 J/kgCritical Temperature 647 KCritical pressure 22.1 x 106 PaSpeed of sound 1480 m/s (T=293 K)Relative permittivity 80 (T=298 K)

[Type text] Page 51


5.3.2 Chemical properties of water

Polarity

Two atoms, connected by a covalent bond, may exert different

attractions for the electrons of the bond. In such cases the bond

is polar, with one end slightly negatively charged (-) and the

other slightly positively charged (+). Although a water molecule

has an overall neutral charge (having the same number of

electrons and protons), the electrons are asymmetrically

distributed, which makes the molecule polar. The oxygen nucleus

draws electrons away from the hydrogen nuclei, leaving these

nuclei with a small net positive charge. The excess of electron

density on the oxygen atom creates weakly negative regions at the

other two corners of an imaginary tetrahedron.

Water structure - hydrogen bonds

Because they are polarized, two adjacent H2O molecules can

form a linkage known as hydrogen bond. Hydrogen bonds have only

about 1/20 the strength of a covalent bond. A hydrogen bond is

therefore a weak chemical bond between a hydrogen atom in one

polar molecule and a very electronegative atom of a second polar

molecule. The hydrogen of one water molecule will be attracted to

the oxygen of another water molecule. They are usually 4-8

molecules per group in liquid water. The surface tension of water

is due to the hydrogen bonding in the associated groups of water

molecules. Hydrogen bonds are strongest when the three atoms lie

in a straight line. The cohesive nature of water, through the[Type text] Page 52


hydrogen bonding and the small size of the molecule, allowing the

molecules to pack together, is responsible for many of its

unusual properties, such as high surface tension, specific heat,

and heat of vaporization. Molecules of water join together

transiently in a hydrogen-bonded lattice. Even at 37oC, 15% of

the water molecules are joined to four others in a short-lived

assembly known as a "flickering cluster."

[Type text] Page 53


Hydrophilic ('Water Loving') and Hydrophobic ('Water Hating')

Molecules

I. Hydrophilic Molecules

Substances that dissolve readily in water are termed

hydrophilic. They are composed of ions or polar molecules that

attract water molecules through electrical charge effects. Water

molecules surround each ion or polar molecule on the surface of a

solid substance and carry it into solution. Ionic substances such

as sodium chloride dissolve because water molecules are attracted

to the positive (Na+) or negative (Cl-) charge of each ion. Polar

substances such as urea dissolve because their molecules form

hydrogen bonds with the surrounding water molecules.

II. Hydrophobic Molecules

Molecules that contain a preponderance of nonpolar bonds are

usually insoluble in water and are termed 'hydrophobic'. This is

true, especially, of hydrocarbons, which contain many C-H bonds.

Water molecules are not attracted to such molecules as much as

they are to other water molecules and so have little tendency to

surround them and carry them into solution. But the so-called

'Hydrophobic Effect' does not mean that nonpolar molecules are

not attracted to water. When two liquids made of molecules of

similar size and polarities are mixed, they will usually form a

single phase solution, no matter what the relative number of

moles of each species. This is expressed by the jargon that the

two substances are miscible in all proportions. In contrast, when[Type text] Page 54


a highly polar substance, such as water, is mixed with a nonpolar

or weakly polar substance, such as most oils, the substances will

separate into two phases. This phenomenon is usually rationalized

in introductory chemistry text books by saying that oil is

hydrophobic, and thus does not make solutions with water, while

polar small organic acids (such as acetic acid from which house

vinegar is made) are hydrophilic, and thus are miscible with

water.

Membranes in bacteria are composed of phospholipids and

proteins. Phospholipids contain charged or polar group (often

phosphate, hence the name) attached to a 3 carbon glycerol back

bone. There are also two fatty acid chains dangling from the

other carbons of glycerol. The phosphate end of the molecule is

hydrophilic and is attracted to water. The fatty acids are

hydrophobic and are driven away from water. Because phospholipids

have hydrophobic and hydrophilic portions, they do remarkable

things. When placed in an aqueous environment, the hydrophobic

portions stick together, as do the hydrophilic. A very stable

form of this arrangement is the lipid bilayer. This way the

hydrophobic parts of the molecule form one layer, as do the

hydrophilic. Lipid bilayers form spontaneously if phospholipids

are placed in an aqueous environment. The cytoplasmic membrane is

stabilized by hydrophobic interactions (i.e. water induced)

between neighbouring lipids and by hydrogen bonds between

neighbouring lipids. Hydrogen bonds can also form between

membrane proteins and lipids. These are known as membrane

[Type text] Page 55


vesicles and are used to study membrane properties

experimentally. There is some evidence that these structures may

form abiotically and may occur on particles that rain down on

earth from space.

Water as a Solvent - Acids & Bases - pH – Hydration

I. Water as a Solvent

Many substances, such as household sugar, dissolve in water.

That is, their molecules separate from each other, each becoming

surrounded by water molecules. When a substance dissolves in a

liquid, the mixture is termed a solution. The dissolved substance

(in this case sugar) is the solute, and the liquid that does the

dissolving (in this case water) is the solvent. Water is an

excellent solvent for many substances because of its polar bonds.

II. Acids

Substances that release hydrogen ions into solution are called

acids. Many of the acids important in the cell are only partially

dissociated, and they are therefore weak acids-for example, the

carboxyl group (-COOH), which dissociates to give a hydrogen ion

in solution. Note that this is a reversible reaction.

III. Bases

Substances that reduce the number of hydrogen ions in solution

are called bases. Some bases, such as ammonia, combine directly

[Type text] Page 56


with hydrogen ions. Other bases, such as sodium hydroxide, reduce

the number of H+ ions indirectly, by making OH- ions that then

combine directly with H+ ions to make H2O. Many bases found in

cells are partially dissociated and are termed weak bases. This

is true of compounds that contain an amino group (-NH2), which

has a weak tendency to reversibly accept an H+ ion from water,

increasing the quantity of free OH- ions.

IV. Hydrogen Ion exchange

Positively charged hydrogen ions (H+) can spontaneously move

from one water molecule to another, thereby creating two ionic

species. Since the process is rapidly reversible, hydrogen ions

are continually shuttling between water molecules. Pure water

contains a steady state concentration of hydrogen ions and

hydroxyl ions (both 10-7 M).

V. pH

The acidity of a solution is defined by the concentration of H+

ions it possesses. For convenience we use the pH scale, where pH

= _log10 [H+]. For pure water [H+] = 10_7 moles/liter

[Type text] Page 57


5.4 Nitrogen

5.4.1 Physical properties of nitrogen

Nitrogen was discovered in 1772 by Daniel Rutherford who

called it noxious air or fixed air. But it was Lavoisier who, in

1786, isolated it. The name nitrogen comes from Latin

nitrogenium, where nitrum (from Greek nitron) means "saltpetre",

and genes means "forming". Nitrogen is mainly found in the

atmosphere, where it accounts for 78 % by volume of the air we

breathe. Nitrogen is also found:

in the Earth's crust, to a limited extent (in the form of

nitrates, etc.),

in organic form (in the living or dead plants and organisms

which form humus)

and in mineral form (ammonia), and thus contributes to soil

fertility. In gaseous form, nitrogen is a neutral and

colourless gas. It is inert and does not sustain life

Formula N2

Molecular Weight (lb/mol) 28.01Critical Temp. (°F) -232.5Critical Pressure (psia) 492.3Boiling Point (°F) -320.5Melting Point (°F) -345.9Gas Density @ 70°F 1 atm (lb/ft3) 0.0725Specific Volume @ 70°F 1 atm (ft3/lb) 13.80

[Type text] Page 58


Specific Gravity 0.967Specific Heat @ 70°F (Btu/lbmol-°F) 6.97

[Type text] Page 59


5.4.2 Chemical properties of nitrogen

At room temperature, nitrogen is a very inactive gas. It

does not combine with oxygen, hydrogen, or most other elements.

Nitrogen will combine with oxygen, however, in the presence of

lightning or a spark. The electrical energy from either of those

sources causes nitrogen and oxygen to form nitric oxide. Nitric

oxide is more active than free nitrogen. For example, nitric

oxide combines with oxygen and water in the atmosphere to make

nitric acid. When it rains, nitric acid is carried to the earth.

There it combines with metals in the Earth's crust. Compounds

known as nitrates and nitrites are formed.

Changing nitrogen as an element to nitrogen in compounds is

called nitrogen fixation. The reaction between nitrogen and

oxygen in the air when lightning strikes is an example of

nitrogen fixation. Certain bacteria have developed methods for

fixing nitrogen. These bacteria live on the root hairs of plants.

They take nitrogen out of air dissolved in the ground and convert

it to compounds, such as nitrates. Those nitrates are used to

make protein molecules, compounds vital to the building and

growth of cells.

Plants, animals, and humans do not have the ability to fix

nitrogen. All living organisms on Earth depend on soil bacteria

to carry out this process. Plants can grow because the bacteria

fix nitrogen for them. They use the fixed nitrogen to make

[Type text] Page 60


proteins. Animals and humans can survive because they eat plants.

They also depend on the soil bacteria that allow plants to make

proteins. So all living creatures rely on soil bacteria to fix

their nitrogen for them and , therefore, to survive.

[Type text] Page 61


5.5 Methane

5.5.1 Physical properties of methane

Normally, methane is a colorless, odorless gas which is lighter

than air. It is formed by the decomposition of organic carbons

under anaerobic condition and is commonly found in or near swamps

and wetland areas, peat deposit or in the area of old landfills.

The rate and rapidity of methane production depends on many

factors, including the amount of rainfall penetrating to and

through the organic matter, the temperature, and the type of the

organic materials. Changes in these conditions, even many years

after the organic matter has been placed on a site, can result in

marked changes in the rate of methane production.

Formula CH4

Molecular Weight (lb/mol) 16.04Critical Temp. (°F) -116.2Critical Pressure (psia) 673.0Boiling Point (°F) -258.7Melting Point (°F) -296.5Gas Density @ 70°F 1 atm (lb/ft3) 0.0416Specific Volume @ 70°F 1 atm (ft3/lb) 24.06Specific Gravity 0.565Specific Heat @ 70°F (Btu/lbmol-°F) 8.53

[Type text] Page 62


5.5.2 Chemical properties of methane

Methane burns in air with a blue flame. We have seen earlier

that in sufficient amount of oxygen, methane burns to give

carbon dioxide and water. In insufficient oxygen it gives out

carbon monoxide. Methane produces a good amount of heat when it

undergoes combustion. This is the reason why it is used as

fuel.Methane is quite unreactive, except with fluorine,

chlorine, etc. With these it undergoes substitution reactions.

Methane undergoes oxidative pyrolysis to form carbon monoxide.

It is formed by reaction of methane with methyl radical which

further reacts to formaldehyde. Then formaldehyde reacts to

formal radical to form carbon monoxide. · The strength of

carbon hydrogen covalent bonds in strongest among all

hydrocarbons. It also undergoes halogenation.

[Type text] Page 63


5.6 Ethane

5.6.1 Physical properties of ethane

Ethane it is also colourless gas at room temperature and

pressure. Melting point and boiling point normally at -169 °C and

– 104°C.In addition, ethane also slightly sweet smell, flammable

and non-polar molecule where it is soluble in non-polar solvent

and insoluble in polar solvents like water. It is also known as

reactive which is the active site is the double bond normally

readily undergoes addition reactions, for example The rate and

rapidity of methane production depends on many factors, including

the amount of rainfall penetrating to and through the organic

matter, the temperature, and the type of the organic materials.

Changes in these conditions, even many years after the organic

matter has been placed on a site, can result in marked changes in

the rate of methane production.


Specific Gravity 1.04

Specific Volume (ft3/lb, m3/kg) 13.025,

0.815

Density of liquid at atmospheric pressure (lb/ft3,

kg/m3)

28, 449

Absolute Viscosity (lbm/ft s, centipoises) 64 10-6,

[Type text] Page 64

http://www.engineeringtoolbox.com/dynamic-absolute-kinematic-viscosity-d_412.html

http://www.engineeringtoolbox.com/density-specific-weight-gravity-d_290.html

http://www.engineeringtoolbox.com/density-specific-weight-gravity-d_290.html

http://www.engineeringtoolbox.com/molecular-weight-gas-vapor-d_1156.html


0.095

Sound velocity in gas (m/s) 316

Specific Heat - cp - (Btu/lboF or cal/goC, J/kgK) 0.41, 1715

Specific Heat Ratio - cp/cv 1.20

Gas constant - R - (ft lb/lboR, J/kgoC) 51.4, 276

Thermal Conductivity (Btu/hr ft oF, W/moC) 0.010, 0.017

Boiling Point - saturation pressure 14.7 psia

and 760 mm Hg - (oF, oC)

-127, -88.3

Latent Heat of Evaporation at boiling point

(Btu/lb, J/kg)

210, 488000

Freezing or Melting Point at 1 atm (oF, oC) -278, -172.2

Latent Heat of Fusion (Btu/lb, J/kg) 41, 95300

Critical Temperature (oF, oC) 90.1, 32.2

Critical Pressure (psia, MN/m2) 709, 4.89

Critical Volume (ft3/lb, m3/kg) 0.076,

0.0047

Flammable Yes[Type text] Page 65


Heat of combustion (Btu/lb, kJ/kg) 22300, 51800

[Type text] Page 66


5.6.2 Chemical properties of ethane

In the laboratory, ethane may be conveniently prepared by Kolbe

electrolysis. In this technique, an aqueous solution of

an acetate salt is electrolysed. At the anode, acetate is

oxidized to produce carbon dioxide and methyl radicals, and the

highly reactive methyl radicals combine to produce ethane:

CH3COO− → CH3• + CO2 + e−

CH3• + •CH3 → C2H6

Another method, the oxidation of acetic anhydride by peroxides,

is conceptually similar.

The chemistry of ethane also involves chiefly free radical

reactions. Ethane can react with the halogens,

especially chlorine and bromine, by free radical halogenation.

This reaction proceeds through the propagation of

the ethyl radical:

C2H5• + Cl2 → C2H5Cl + Cl•

Cl• + C2H6 → C2H5• + HCl

Because halogenated ethane can undergo further free radical

halogenation, this process results in a mixture of several

halogenated products. In the chemical industry, more selective

chemical reactions are used for the production of any particular

two-carbon halocarbon.

[Type text] Page 67

http://en.wikipedia.org/wiki/Hydrochloric_acid

http://en.wikipedia.org/wiki/Ethyl_chloride

http://en.wikipedia.org/wiki/Chlorine

http://en.wikipedia.org/wiki/Ethyl_group

http://en.wikipedia.org/wiki/Free_radical_halogenation

http://en.wikipedia.org/wiki/Bromine

http://en.wikipedia.org/wiki/Chlorine

http://en.wikipedia.org/wiki/Halogen

http://en.wikipedia.org/wiki/Free_radical_reaction

http://en.wikipedia.org/wiki/Free_radical_reaction

http://en.wikipedia.org/wiki/Peroxide

http://en.wikipedia.org/wiki/Acetic_anhydride

http://en.wikipedia.org/wiki/Electron

http://en.wikipedia.org/wiki/Carbon_dioxide

http://en.wikipedia.org/wiki/Acetate

http://en.wikipedia.org/wiki/Methyl


http://en.wikipedia.org/wiki/Anode

http://en.wikipedia.org/wiki/Electrolysis

http://en.wikipedia.org/wiki/Acetate

http://en.wikipedia.org/wiki/Kolbe_electrolysis

http://en.wikipedia.org/wiki/Kolbe_electrolysis


Combustion

The complete combustion of ethane releases 1559.7 kJ/mol, or 51.9

kJ/g, of heat, and produces carbon dioxide and water according to

the chemical equation

2 C2H6 + 7 O2 → 4 CO2 + 6 H2O + 3170 kJ

Combustion occurs by a complex series of free-radical

reactions. Computer simulations of the chemical kinetics of

ethane combustion have included hundreds of reactions. An

important series of reaction in ethane combustion is the

combination of an ethyl radical with oxygen, and the subsequent

breakup of the resulting peroxide into ethoxy and hydroxyl

radicals.

C2H5• + O2 → C2H5OO•

C2H5OO• + HR → C2H5OOH + •R

C2H5OOH → C2H5O• + •OH

The principal carbon-containing products of incomplete ethane

combustion are single-carbon compounds such as carbon

monoxide and formaldehyde. One important route by which the

carbon-carbon bond in ethane is broken to yield these single-

carbon products is the decomposition of the ethoxy radical into

amethyl radical and formaldehyde, which can in turn undergo

further oxidation.

C2H5O• → CH3• + CH2O

[Type text] Page 68

http://en.wikipedia.org/wiki/Formaldehyde

http://en.wikipedia.org/wiki/Methyl

http://en.wikipedia.org/wiki/Formaldehyde

http://en.wikipedia.org/wiki/Carbon_monoxide

http://en.wikipedia.org/wiki/Carbon_monoxide

http://en.wikipedia.org/wiki/Free_radical

http://en.wikipedia.org/wiki/Oxygen

http://en.wikipedia.org/wiki/Peroxide


http://en.wikipedia.org/wiki/Chemical_kinetics

http://en.wikipedia.org/wiki/Computer_simulation

http://en.wikipedia.org/wiki/Water



http://en.wikipedia.org/wiki/Chemical_equation

http://en.wikipedia.org/wiki/Water


http://en.wikipedia.org/wiki/Combustion


Some minor products in the incomplete combustion of ethane

include acetaldehyde, methane, methanol, and ethanol. At higher

temperatures, especially in the range 600–900 °C, ethylene is a

significant product. It arises via reactions like

C2H5• + O2 → C2H4 + •OOH

Similar reactions (although with species other than oxygen as the

hydrogen abstractor) are involved in the production of ethylene

from ethane in steam cracking.

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http://en.wikipedia.org/wiki/Steam_cracking

http://en.wikipedia.org/wiki/Ethylene


http://en.wikipedia.org/wiki/Ethylene

http://en.wikipedia.org/wiki/Ethanol

http://en.wikipedia.org/wiki/Methanol

http://en.wikipedia.org/wiki/Methane

http://en.wikipedia.org/wiki/Acetaldehyde


5.7 Hydrogen

5.7.1 Physical properties of hydrogen

The physical properties of hydrogen are it is in gas state at

room temperature. Hydrogen is a colourless, tasteless and

odourless gas. In addition, it is the lightest gas and it is

insoluble in water. Hydrogen also is highly inflammable and burns

with blue flame forming water. The right temperature for

liquefaction of hydrogen is -252oC.The bond energy of H-H is 431

Kj/mole whereas the electro negativity of hydrogen is

2.1.Besides, ionization potential of hydrogen gas is 13.54

electron volt.

Colourless

Highly flammable

Light in weight

Density : 0.0899*10 -3 g.cm -3 at 20 °C

Melting point : - 259.2 °C

Boiling point :- 252.8 °C

Pure hydrogen is a gas under normal conditions.

Hydrogen is diatomic and much lighter than air.

It has such small mass that it can escape earth's gravitational

pull and fly off into space.

The gas mixes well with air, explosive mixtures are easily

formed.

The gas is lighter than air.

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V.7. 2 Chemical properties of hydrogen

Electronegativity according to Pauling : 2.1

Energy of first ionisation : 1311 kJ/mol

Reacts easily with other chemical substances.

Hydrogen is slightly more soluble in organic solvents than in

water.

It does not usually react with other chemicals at room

temperature.

Two hydrogen molecules (H2) and one oxygen molecule (O2),

combine to form two molecules of water, or H2O. This reaction

releases energy.

Hydrogen bonds form covalent bonds with each other and with

other atoms.

In some molecules containing hydrogen, the covalent bond

between one of the hydrogen atoms and another atom is weak and

breaks easily. Compounds made of these bonds are called acids.

Hydrogen also forms ionic bonds with some metals, creating a

compound called a hydride.

Hydrogen can also form a unique bond known as a hydrogen bond.

Hydrogen bonds only form between hydrogen and the elements

oxygen (O), nitrogen (N), or fluorine (F). Water is a good

example of hydrogen bonding.

Many metals absorb hydrogen. Hydrogen absorption by steel can

result in brittle steel, which leads to fails in the chemical

process equipment.

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At normal temperature hydrogen is a not very reactive

substance.

Atomic hydrogen reacts with organic compounds to form a complex

mixture of products.

Hydrogen reacts with oxygen to form water and this reaction is

extraordinarily slow at ambient temperature.

Under extreme pressure hydrogen can actually act like a metal.

Heating may cause violent combustion or explosion.

Reacts violently with air, oxygen, halogens and strong oxidants

causing fire and explosion hazard.

Hydrogen is widely used as a reducing agent.

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5.8 Carbon Dioxide

5.8.1 Physical properties of carbon dioxide

Carbon dioxide is colorless. At low concentrations, the gas is

odorless. At higher concentrations it has a sharp, acidic odor.

At standard temperature and pressure, the density of carbon

dioxide is around 1.98 kg/m3, about 1.5 times that of air. At

atmospheric pressure and a temperature of −78.51 °C (−109.32 °F),

carbon dioxide changes directly from a solid phase to a gaseous

phase through sublimation, or from gaseous to solid

through deposition.

Liquid carbon dioxide forms only at pressures above 5.1 atm,

the triple point of carbon dioxide is about 518 kPa at −56.6 °C.

The critical point is 7.38 MPa at 31.1 °C. Another form of solid

carbon dioxide observed at high pressure is an amorphous glass-

like solid. This form of glass, called carbonia, is produced

by super cooling heated CO2 at extreme pressure (40–48 GPa or

about 400,000 atmospheres) in a diamond anvil. This discovery

confirmed the theory that carbon dioxide could exist in a glass

state similar to other members of its elemental family,

like silicon (silica glass) and germanium dioxide. Unlike silica

and germania glasses, however, carbonia glass is not stable at

normal pressures and reverts to gas when pressure is released.

Formula CO2

Molecular Weight (lb/mol) 44.01

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Critical Temp. (°F) 87.9Critical Pressure (psia) 1071.0Boiling Point (°F) -109.2Melting Point (°F) -69.9Psat @ 70°F (psia) 852.8Liquid Density @ 70°F (lb/ft3) 47.64Gas Density @ 70°F 1 atm (lb/ft3) 0.1144Specific Volume @ 70°F 1 atm (ft3/lb) 8.74Specific Gravity 1.555Specific Heat @ 70°F (Btu/lbmol-°F) 8.92

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5.8.2 Chemical properties of carbon dioxide

Carbon dioxide is a linear covalent molecule. Carbon dioxide is

an acidic oxide and reacts with water to give carbonic acid.

CO2 + H2O ==> H2CO3

Carbon dioxide reacts with alkalis to give carbonates and

bicarbonates.

CO2 + NaOH ==> NaHCO3

Sodium BiCarbonate

NaHCO3 + NaOH ==> Na2CO3 + H2O

Sodium Carbonate

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6.0 References

1. Ttmethanol.com. (2014). Manufacture of Methanol. Retrieved 10

March 2014, from

http://www.ttmethanol.com/web/methprocess.html#

2. Methanol.org. (2014). The Methanol Industry - Methanol

Institute. Retrieved 10 March 2014, from

http://www.methanol.org/Methanol-Basics/The-Methanol-

Industry.aspx

3. Naturalgas.org. (2014). NaturalGas.org - Brought to you by

NGSA. Retrieved 10 March 2014, from http://www.naturalgas.org

4. Communications, T. (2014). Chemical Systems: Return on

Analysis for Investment in the Petrochemical Industry:

Markets, Technology, Profitability and Prices.

Chemsystems.com. Retrieved 11 March 2014, from

http://www.chemsystems.com/about/cs/news

5. Dgmk.de. (2014). Synthesis Gas Lurgi. Retrieved 13 March 2014,

from www.dgmk.de/petrochemistry/abstracts_content14/Wurzel

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http://www.dgmk.de/petrochemistry/abstracts_content14/Wurzel

http://www.chemsystems.com/about/cs/news

http://www.naturalgas.org/

http://www.methanol.org/Methanol-Basics/The-Methanol-Industry.aspx

http://www.methanol.org/Methanol-Basics/The-Methanol-Industry.aspx

http://www.ttmethanol.com/web/methprocess.html


6. Martyn S. Ray and David W. John, Chemical Engineer Design

Project: A Case Study Approach, 1989, Gordon and Breach

Science Publishers.

7. Kirk Othmer, Encyclopedia of Chemical Technology Volume 16,

4th Ed.

8. Fritz Ullmann’s et. Al, 2003, Ullmann’s Encyclopedia of

Industrial Chemistry: Methanol, vol. 11, John Wiley & Sons

Inc.

9. Richard M. Felder and Ronald W. Rousseau, 2005, Elementary

Principles of Chemical Process, 3rd Ed., page 83, John Wiley

& Sons Inc.

10. R. K. Sinnott, 1999, Coulson & Richardson’s Chemical

Engineering: Chemical Engineering Design, Vol. 6, 3rd Ed.,

Butterworth-Heinemann.

11. James G. Speight, 2002, Chemical Process Design Handbook,

McGraw-Hill Inc.

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methanol production

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