DPA/53

School of Mechanical and Aerospace Engineering

Report on Industrial Attachment

Marine Scrubbers & Ballast Water Management Systems (BWMS)

(Semester 1, AY 2016-2017)

Prepared by: Sameer Khattar

U1421800L

MAE

Table of Contents Page

ABSTRACT i

ACKNOWLEDGEMENTS ii

INTRODUCTION

Background of the Industrial Attachment 3

Purpose, Nature and Scope of the Report 5

Chapter 1 – COMPANY PROFILE

1.1 About the Organisation 7

1.2 Organisation Structure 8

Chapter 2 – SCRUBBER PROJECT

2.1 Types of Scrubbers 9

2.2 Summary of the various scrubbers 11

2.3 Feasibility Studies 11

Chapter 3 – RETROFITTING LOCAL OPERATED FERRY WITH LNG

3.1 Type of ship system modification 19

3.2 Identification of Hazardous zones 21

3.3 LNG Importers and Exporters 22

3.4 LNG Supply Chain 23

3.5 LNG vs Scrubber Spider Diagram 26

Chapter 4 – FEASIBILITY STUDY OF POWERING FUEL CELL FERRY WITH RENEWABLE ENERGY

4.1 Economic Study 27

4.2 Levelised Cost of Electricity (LCOE) & Levelised Cost of Hydrogen (LCOH) Calculation 30

Chapter 5 – HORIZON 9 FERRY PROJECT

5.1 Fuel Consumption vs Load 33

5.2 Graphical Analysis 35

Chapter 6 – BALLAST WATER MANAGEMENT SYSTEMS

6.1 Optimisation data set up 39

6.2 Ballast Water Management Systems 45

6.3 Ballast Water Profiling 48

CONCLUSION 49

REFERENCES 50

Appendix A – Stability Data 51

Abstract

The author interned at DNV GL - A maritime, oil and gas and energy industry for a

period of 20 weeks from August to December 2016. Driven by our purpose of

safeguarding life, property and the environment, the attachment provided valuable

exposure to the use of Marine Scrubbers and Ballast Water Management Systems for

safer, smarter and greener operations.

This report presents the knowledge acquired by the author through describing his

assigned projects. The responsibilities undertaken and the tasks accomplished helped

the author to develop key skills like communicating effectively, presentation skills

and self-learning.

The attachment experience fulfilled its objectives of providing an insight into how an

industry works. The courses undertaken by the author in NTU also helped him to

contribute to projects comprehensively and made this attachment a more rewarding

and an enjoyable one.

Page | 1

AcknowledgementsThe author would like to thank DNV GL for providing the opportunity to complete

his 20-week industrial attachment at the company. The author is also grateful NTU’s

Career and Attachment Office, whose informative talks and emails kept him and his

supervisor up to date with all the deadlines and most importantly, without whom, the

author would not have been able to be a part of such a brilliant opportunity to work

in the industry.

For the staff at DNV GL, the author would like to take this opportunity to express his

heartiest gratitude. Without them, this attachment experience wouldn’t have been as

memorable. The support and guidance offered by all the staff was very friendly and

courteous. This ensured that the author was continuously learning every day.

The author would like to thank his IA tutor – Prof Chai Gin Boay for his continual

guidance and support during the 20 weeks of attachment.

The author would also like to express his heartiest gratitude to his supervisors –

Dr Alam Khorshed and Haniza Binte Mustaffa who was always there to support him.

The author learnt a lot of new things under their mentorship. Their friendly nature,

guidance and feedback really kept the author going throughout his attachment.

Page | 2

Introduction

Background of the Industrial Attachment

As a part of NTU’s School of Mechanical and Aerospace Engineering’s curriculum,

the author was required to complete his 20 – week Industrial Attachment with an

industrial organization in his third year of study. The IA programme is one of the

many successful innovative features of engineering education at NTU. This

attachment allows undergraduates to gain practical learning experience outside of the

normal academic curriculum. It is an enriching experience where students get a

glance into what life after university will be like.

The author chose to do his attachment with DNV GL. Operating in more than 100

countries, DNV GL enables organizations to advance the safety and sustainability of

their business. The company provides classification, technical assurance, software

and independent expert advisory services to the maritime, oil & gas and energy

industries. DNV GL continuously invests in research and collaborative innovation to

provide customers and society with operational and technological foresight.

Operating in more than 100 countries, professionals are dedicated to helping

customers make the world safer, smarter and greener.

Page | 3

Scrubbers are a critical part of a ship/vessel - They reduce Sulphur (SO2) and

particulate emissions from ship engines, generators, and boilers and hence, feasibility

studies on different types of scrubbers were conducted. The other project was

regarding Ballast Water Management Systems (BWMS) with the aim of protecting

the marine environment from the transfer of harmful aquatic organisms in ballast

water carried by ships for stability purposes onboard operations.

This internship was the first crucial stepping stone towards a career in a Maritime

engineering industry. The author learnt a lot about this aspect during his stay at DNV

GL simultaneously while developing the skills required for a professional engineer.

Page | 4

Purpose, Nature and Scope of the Report

The author has prepared this descriptive report to summarize his 20 weeks

attachment programme at DNV GL. This report highlights the various projects the

author was involved in during the attachment and how the projects involved analysis,

synthesis and interpretation of data/information. This report is an important part of

the total practical training experience that the author gained and also acts as a

supplement to the following objectives expected of the author:

Acquire basic understanding of types of scrubbers

Perform feasibility studies on the various types of scrubbers

Research, profiling and design parameters of Ballast Water tanks/ Ballast

Water Management Systems (BWMS)

Apply relevant concepts & skills obtained theoretically in school into a

real life industrial setting

To perform futuristic studies/data analysis on Wind Energy production /

Fuel Cell / Hydrogen Generation & Shipping

To gain exposure to the operation intricacies and professional skills of an

Marine Engineer

Demonstrate professionalism & aptitude during work

Page | 5

The author was attached to the Maritime Advisory Department under the Eco

Research Centre. The author assisted in various ongoing projects and completed a

few projects on his own with constant guidance from the team. The report that

follows describes 2 major projects that the author assisted in – Feasibility Studies on

types of Marine Scrubbers as well as research on Ballast Water Management

Systems (BWMS) / Ballast Water tanks to minimise the accumulation of sediments

and protecting the marine environment from the transfer of aquatic organisms which

may be harmful to the environment during transfer.

Every project chapter begins with a brief background about the project. It then goes

on to explain how and what the author contributed to the project and lastly, author’s

reflections about the project related tasks. The report captures the major aspects of

the above mentioned projects and presents what the author learnt about various

operations and procedures of the organisation through these projects.

Page | 6

Chapter 1 – Company Profile

1.1 About the organisation – DNV GL

DNV GL is a world-leading classification society and risk management company,

driven by our purpose of safeguarding life, property and the environment. The

company enables organizations to advance the safety, efficiency and sustainability of

their business. DNV GL origins stretch back to 1864, and the reach today is global.

Operating in more than 100 countries, our 15,000 professionals are dedicated to

helping customers make the world safer, smarter and greener. DNV GL also

strengthened their ability to assure the value chain of companies across a wide range

of industries – helping them build trust and confidence with their stakeholders.

Purpose

To safeguard life, property and the environmentVision

Global impact for a safe and sustainable futureValues

We build trust and confidence We never compromise on quality or integrity We are committed to teamwork and innovation We care for our customers and each other

We embrace change and deliver results

Page | 7Figure 1.1 – DNV GL

1.2 Organisation Structure

DNV GL has 5 different departments: Maritime, Oil & Gas, Energy, Business

Assurance and Software. The following figure shows the organisational hierarchy

and where the author was attached.

Figure 1.2 – Organisational Structure

Page | 8

Chapter 2 - Scrubber Project

2.1 Types of Scrubbers

A scrubber is a machine capable of scrubbing and removing sulphur oxides (SOx)

from the exhaust of an engine. This would allow the ship to continue to run heavy

fuel oil (HFO).

Figure 2.1 – Types Of Scrubbers

An open loop scrubber uses the natural alkalinity of seawater to neutralize and

remove acidic SOx from the exhaust gas. Water enters the sea chest through a sea

water pump and is directed into the scrubber. Exhaust gas enters the scrubber inlet

and rises to exit through the scrubber outlet. As the exhaust gas is rising, it is mixed

with sea water through nozzles in the scrubber, where SOx is removed from the

exhaust emissions, before exiting through the scrubber outlet. The contaminated

water exiting the scrubbing unit is mixed and diluted with more seawater before

being discharged into the sea as wash water.Page | 9

A closed loop scrubber, unlike the open loop scrubber, does not use sea water to

remove SOx from the exhaust emissions. Instead it uses fresh water mixed with

caustic soda (NaOH) to neutralize the sulphur in the exhaust. The alkaline water is

circulated within the scrubber to remove SOx from the exhaust gas. After scrubbing,

the water is filtered, with its waste products (SOx, Unreacted NaOH etc.) removed as

sludge and stored in the sludge tank. The filtered water is then recirculated into the

scrubber.

Hybrid scrubbers are able to operate as an open loop system as well as a closed loop

system. This way, a hybrid scrubber is able to achieve the benefits of both types of

scrubbers as mentioned above. Ship owners employing the use of hybrid scrubbers

are able to operate in either modes depending on the alkalinity of the water they are

travelling water, and whether there are any wash water discharge regulations.

Lastly, dry scrubbers use caustic lime (Ca(OH)2) to react with the SOx in the exhaust

gas. The pneumatic conveyor system feeds the Ca(OH)2 into the scrubbing unit the

lime is mixed with the exhaust gas. Gypsum (CaSO4) is produced as waste to be

disposed of at a harbor.

Page | 10

2.2 Summary of the various Scrubbers

Figure 2.2 – Comparison of Scrubbers

2.3 Feasibility Studies

1) Operational Feasibility

Operational feasibility of a scrubber refers to whether a scrubber is able to help a

ship owner comply with the IMO regulations while still running on HFO. HFO has a

sulphur content of up to 35,000 parts per million (ppm). When travelling in an ECA, Page | 11

this amount has to be reduced to 1000 ppm (Wang, The end of the era of heavy fuel

oil in maritime shipping, 2014). This is translates to a 97% reduction of sulphur

emissions.

Figure 2.3 – Operational Feasibility of the various scrubbers

From the table above, the dry scrubber is too heavy, hence affecting the ships

stability, hindering safe operations. Open loop scrubbers might have lower

efficiencies where alkalinity of water is low for the wash water method. Hybrid

scrubbers has a larger power consumption than closed scrubbers, hence making

closed loop scrubbers the best available option for scrubbers operational feasibility.

Page | 12

2) Technical Feasibility

Technical feasibility encompasses factors such as dimensions, space, weight,

pressure drop, stability and certain advantages and disadvantages of retrofitting a

scrubber onto a ship. One of the most important factors we have to take into

consideration is the stability of the ship / vessel. This can be analysed as follows:

Figure 2.4 – Stability Concept

The Centre of Gravity (G) through which gravity exerts a downward force equal

to the displacement of the boat

The Centre of Buoyancy (B), being the centre of the underwater volume of the

boat, whose upward thrust counteracts the effect of gravity acting through G

The horizontal distance (GZ) between G and B.

The location of G is fixed, unlike B which changes as the boat heels and the

immersed section changes shape.

Page | 13

As the Centre of Gravity and the Centre of Buoyancy initially move apart and

then converge, so the length of GZ - the righting lever - increases and decreases.

This relationship between heel angle and righting moment governs the shape of

the GZ curve and defines the boats static stability.

The range of stability – where all GZ values are positive.

The maximum GZ lever & the angle at which it occurs.

The angle of vanishing stability – beyond which the vessel will capsize.

The area of negative stability.

The moment of statical stability at any given angle of heel :

(GZ x Displacement of the ship)

(Examples of the stability report for the Horizon 38m Monohull ferry can be shown

in Appendix A)

Page | 14

Figure 2.5 – Technical Feasibility

Evaluating on just the technical aspect of the various scrubbers, dry scrubbers are not

preferred over wet scrubbers due to its tremendous weight and lesser TEU capacity

(Twenty Foot Equivalent Unit).

Page | 15

Open loop scrubbers seem like the best option as there isn’t a need for NaOH

(Sodium Hydroxide) injection or any extra tanks/units for storage unlike closed and

hybrid scrubbers.

3) Economic Feasibility

Figure 2.6 – Economic Feasibility

* Total Cost (Actual price + Installation + Maintenance) for the various scrubbers are as follows:

Wet – 3.52 Mil

Hybrid – 5.02 Mil

Dry – 1.86 Mil

Page | 16

Dry scrubbers have lower capital and annual costs than wet scrubbers because it is

simpler, demand less water and waste disposal is less complex. Therefore, dry

scrubbers are the most economically feasible.

Although there are many economic advantages of the dry scrubber like low operating

costs, we cannot disregard the high running costs of Ca(OH)2 - (€1.3/kg). Also, the

dust cake consists of Ca(OH)2 and the uncollected particles which are collected in

the fabric filter have to be cleaned - which add into maintenance costs. However, the

collected solids can be recycled to reduce the use and costs of the reagent.

4) Maintenance

Dry scrubbers are preferred over wet scrubbers in terms of maintenance. The

following reasons show why:

Page | 17

Thus, scrubber selection/feasibility varies for different sectors of study, namely:

Operational, Technical, Economic and Maintenance. Ultimately, scrubbers have to

fulfil the objective of a sufficiently high efficiency rate to reduce sulphur emissions

to a lowest possible percentage - 0.1 % at the minimum at ECA (Emission Controlled

Areas) based on the IMO (International Maritime Organisation) regulations.

Figure 2.7 – Scrubber Modelling (Solidworks) by Sun, Miaoyan

Page | 18

Chapter 3–Retrofitting Local Operated Ferry with LNG

Built in 2014, the Horizon 9 high-speed ferry is currently in service between Batam of

Indonesia and Singapore (the vessel Flag), in average temperature of 80 °F (27 °C) with

little seasonal variation.

3.1 Type of ship system modification

LNG containment system

1) Pressure Build Up (PBU) unit

The tank operates without a pressure pump. Hence, the LNG/NG is transported

without the help of any mechanical pump. This is achieved with the help of a

Pressure Build Up unit. The PBU regulates the internal pressure of the tank by

varying the amount of natural gas inside the tank. The difference in pressure also aids

in the LNG to flow from the tank, through the PBU to the vaporiser and

consequently to the gas train.

2) Vaporiser Skid

The vaporiser skid, along with the PBU is essential to the NG fuel system

mechanism. As the name suggests, the vaporiser skid helps to vaporise the LNG to

NG. The vaporiser uses a hot water system to provide the necessary energy to change

Page | 19

the state of LNG from liquid to gaseous. The vaporiser skid along with the PBU is

known as the coldbox and it comes attached to the LNG tank.

Figure 3.1 – Vaporiser Skid

Bunkering system

A new LNG bunkering system for the ferry connection with the LNG terminal,

bunkering barge or truck will have to be constructed. Important expect of the

bunkering system includes double walled vacuum insulated piping to maintain

flowing LNG temperature, proper ventilation system to remove accumulation of

gases in compartment and boil off gas arrangement.

Figure 3.2 – LNG Pipelines

Page | 20

Another key concept to implement would be the nitrogen system to inert the LNG

pipelines. Bunkering regulations dictate the use of nitrogen system as a safety

measure on board LNG fuelled ships or carriers. This is necessary in order to purge

any oxygen or NG that is present in the pipelines.

Safety System

Some of the safety systems the author researched about were ESD valve, earthing

cables, bilge water tanks, air lock, tank room hatch, gas mast, gas venting outlet,

ventilation inlet and water seals

3.2 Identification of Hazardous Zones

Figure 3.3 – Hazardous Zones

Page | 21

3.3 LNG Importers and Exporters

LNG terminals can act as the intermediary storage between the producer and end-

consumer. These terminals are usually able to store the LNG for a specified period of

time before importing/exporting/using the LNG. These terminals will be an

important part of the supply chain because the presence of existing LNG terminal

infrastructure strongly correlates to extensions of the natural gas network. The author

also identified the LNG exporters and importers in the South East Asia region –

Countries where LNG terminals are existing/under construction (or both/none).

Figure 3.4 – LNG Importers / Exporters

3.4 LNG Supply Chain

Page | 22

Located on a 40-hectare plot at the southern-most tip of Jurong Island, the Singapore

LNG Terminal is the first open-access, multi-user LNG terminal in Asia.

Figure 3.5 – LNG Terminal in Jurong

The LNG terminal receives and stores energy unloaded from LNG carriers. LNG will

be stored and regasified at the LNG terminal from where it will be sent out into the

local market and onto the end users. The LNG terminal is designed to deliver

regasified LNG at a maximum pressure at 40 barg and a minimum pressure of 13

degree Celsius.

Page | 23

The LNG carries out the following main operations:

Figure 3.6– LNG Supply

Chain

Page | 24

Figure 3.7 – Major Ferry Routes (Singapore to Batam)

Potential New Business:

1) Cold Energy Utilisation Services – to provide a load cooling service to

industrial customers, using ‘cold’ energy from the terminal’s regasification

process

2) Liquefied Petroleum Gas (LPG) Terminal – to install an LPG import/storage

facility for distribution to the local market

3) LNG Trucking – to enable LNG road tankers to be loaded at the terminal so

that LNG can be transported overland to various parts of Singapore that

maybe constrained by the Singapore Gas Network.

Page | 25

3.5 LNG vs Scrubber - Spider Diagram

The author came up with a comparison analysis between LNG and scrubber. He

rated the following characteristics from 1.0 to 5.0 – with 5.0 being the least in value

and 1.0 being the largest in value. An example is shown below:

For example, under ‘Content of Sulphur (Emissions)’ – LNG is rated at 5.0 and

Scrubber at 2.0.

LNG has a higher rating (less in value) which ultimately states that using LNG has

lesser sulphur emissions than retrofitting scrubbers onto vessels.

Page | 26

LNG

Scrubber

Chapter 4 - Feasibility study of powering fuel cell ferry with renewable energy

4.1 Economic Study

For this study, the author calculates the Levelized Cost of Electricity (LCOE) that is

to power the fuel cell motor for propulsion and other operation such as berthing.

LCOE =

The total cost of electricity to drive the fuel cell ferry fleet can be summarized in the

following tables. It consists of

1. Cost of wind farm

2. Cost of hydrogen production and shipping

3. Cost of fuel cell system

To obtain the value of the total cost of electricity in 20 years, we use the formula:

n-1

*For this study, the total cost includes 3% inflation along the 20 years.

Page | 27

Figure 4.1 – Total Cost of Electricity:

Wind Farm, Hydrogen Production & Shipping, Fuel Cell

In the space below, the author shows how he calculates the total cost of electricity in

20 years for the respective components.

Page | 28

Total Cost of Electricity

(Wind Farm)

Total Cost of Electricity (Fuel Cell)

Total Cost of Electricity

(Hydrogen Production & Shipping)

Figure 4.2 – Calculations

For the above picture, we include the annual shipping cost into the OPEX. For

example, the value of (OPEX + SHIPPING) would be 2.42 + 0.63 = 3.05

To obtain the value of the total cost in 20 years,

we input this formula into the excel cell:

=ROUND(CAPEX+SUMPRODUCT((O+S)*1.03^1:19),2)

to obtain the TOTAL value for 20 years

*Reference to excel spreadsheet

4.2 Levelised Cost of Electricity (LCOE) & Levelised Cost of

Hydrogen (LCOH) CalculationPage | 29

Upon deriving the total cost, the LCOE can be calculated by the following formula:

*Total Cost (20 years) is in million USD

*Total amount of electricity in 20 years is (474,500 x 1000) kWh

The levelised cost of hydrogen produced using wind energy described in this report

can be calculated similarly with the electricity LCOE, except that the costs of fuel

cell are excluded here. They are shown in the following table.

Levelised cost of hydrogen =

*Total tonnes of H2 in 20 years = 4.64 * 365 * 20 = 33872 tonnes

*Total Cost (20 years) is in million USD

*Total tonnes, H2 (20 years) = (33872 x 1000) kg

The following figures show how it is derived on Microsoft Excel:

Page | 30

Total electricity produced in 20 years =

65 * 365 * 20 = 474,500MWh

Figure 4.3 – Excel Spreadsheet Calculations

For example, LCOE (Onshore, 1.65MW, Steam, Gas) =

Page | 31

(C22+C36+C46)*(1000000) / (C50*1000) – (Highlighted in yellow)

The levelised hydrogen costs are much higher than the cost derived from market

data. The main reason is the high capital cost of wind farm for generating electricity.

Compared to the traditional coal fire power plant, wind farm has the disadvantage of

higher capital cost and shorter lifetime (typically 20 years compared to 30+ years for

thermal power plants), which results a much higher electricity LCOE cost.

Chapter 5 – Horizon 9 Ferry Project Page | 32

5.1 Fuel Consumption vs Load

The Horizon 9 fast ferry, located at Harbourfront Centre, secured the most

competitive route in Southeast Asia between Singapore and Indonesian island of

Batam - therefore offering the most cost efficient choice to travel to Batam.

Horizon introduced to the public with the first vessel Horizon 9 to begin her

operation. These newly build vessels namely, the “Horizon 9”, “Horizon 8”,

“Horizon 7” and “Horizon 6” have a capacity for 238 passengers, including a main

deck seating for 208 passengers, an exclusive upper deck for 30 passengers and a

private saloon for 4 VIPs.

Figure 5.1 – Horizon 9 Ferry

Page | 33

The authors task was to perform an analysis of the Fuel and Power consumption of

the Horizon 9 Ferry during its daily operation. Some data was given to the author

when his supervisor went to site and collected the data. The figure below shows what

was given to the author.

Figure 5.2 - Fuel Consumption vs Load

The Horizon 9 ferry included 3 main engines and 2 auxillary engine (out of which 1

is on standby). The power of the engines is as follows:

Main Engine (CAT C32 ACERT) – 970 kW

Auxillary Engine (Generator) – 86 e kW

5.2 Graphical Analysis

Page | 34

The author then came up with a data table (by simple calculations) of the Horizon 9

ferry during its operations illustrated by the figure below:

Figure 5.3 – Data presented in Microsoft Excel

The highlighted portion represents a one way trip from Batam to Singapore (135

minutes) and 270 minutes for one round trip. The power and the actual fuel oil

consumption for the individual engines (main & auxillary) are tabulated

e.g.1 - Power for 68% load (generator) - 0.68 x 86 = 58.48 e kW

e.g.2 – Fuel Consumption (Engine x 3) – ((22/60) x 3) x 3 = 3.3 litres

Page | 35

After tabulating this data, the author presented it in 2 different formats –

1) Graphical format – Fuel/Power consumption against time

2) Contour Diagram

Fuel Consumption

Page | 36

Power Consumption

Figure 5.4 – Fuel and Power Consumption Data

Page | 37

From the above graphs, we can see the superimposed graph (blue line) – which is the

total power/fuel consumption of the auxillary engine (generator – red line) and the 3

main engines (green line).

From the data tabulated, the author found that 2922.64 ℓ of fuel is used per day and

the maximum power consumed by the 3 engines as well as the auxillary engine

(generator) during the entire day of operation is at 2183 kW.

Page | 38

Chapter 6 – Ballast Water Management Systems (BWMS)

6.1 Optimisation Data Set up

The author has been tasked to research about the design parameters such as input

variables, boundary conditions, scenarios, and optimisation data set up such as

structural configurations to minimise the deposition of sediments in ballast water

tanks.

1) Optimum Structural Configuration

Most double bottom tanks in ships are fitted with longitudinals, intercostals and

floors which give the double bottom of ships their structural strength.

Figure 6.1 – Longitudinals

Page | 39

Where double bottom tanks are fitted with intercostals between the floors, the floors

should be fitted with larger drain holes at the intersection of the intercostals and

floors as shown in the figure below. This has a double advantage of allowing better

access for welding during construction and better flow of water and sediment to the

suction heads.

Figure 6.2 – Side elevation of tank

Page | 40

The structural arrangement in double bottom and other tanks shall be such as to

permit the free passage of air and gases from all parts of the tanks to the vent pipes

Vent pipes for fuel oil tanks shall, wherever possible, have a slope of no less than

30°. Header lines, where both ends are adequately drained to a tank, are excluded

from this requirement. Inside the double bottom tank, individual compartments are

generated by crossing longitudinal and transverse stiffeners and frames with

lightening holes.

Figure 6.3 – Structural Configuration of Ballast Tank

Page | 41

2) Input Variables

Flow rate of Ballasting/De-ballasting

Eg. DIAMOND 53 – HANDYMAX BULK CARRIER

Figure 6.4 – Pressure and flow rate of ballasting/de-ballasting

Particle size distribution

The RC (Rotational Cleaning) filter uses polyester nonwoven fabric. The figure

below shows the changes in the particle size distribution in water before and after

filtration. Since the filter has a degree of separation that reduces the most frequent

particle size of 25 μm in the test seawater to 10 μm or smaller, not only can it remove

L-sized (50 μm or larger) plankton almost completely, it can also remove 50% to

90% of the relatively small S-sized (10 to 30 μm) plankton

Figure 6.5 – Particle Size Distribution

Page | 42

Tank Dimensions (From Solidworks Design) – Half tank

Length: 27m

Height: 16.13m

Width: 20.95m

Figure 6.6 – Ballast water Tank Design

Page | 43

Length

WidthHeight

Lightening Holes

A single ballast tank is really twenty-four (24) steel boxes welded together with

lightening holes just big enough to allow fluid and personnel access between them.

These tanks are longitudinally framed, meaning that smaller structure running from

forward to aft is provided about every 750 mm.

Figure 6.7 – Lightening Holes

Page | 44

6.2 Ballast Water Management Systems

Ballast Water may contain a huge variety of organic life, including nominative

species. If these can be established, it can have a serious ecological, economic and

public health impact on the receiving environment. As part of the Wärtsilä

Partnership programme, ship owners have access to technology choice, offering

filtration with either ultra-violet (UV) or electro-chlorination (EC) ballast water

treatment.

Figure 6.8 – Wartsila Filtration System

How it works

1) Filtration System

A filter installed at ballast pump downstream removes the inflow of sediments or

aquatic organisms which are larger than 50 µm, greatly reduce the uncertainty

from various local marine environment and to perform robust BWTS performance

Page | 45

Figure 6.9 – Inside of a Filter

In case the differential pressure between filter inlet and outlet increases up to 0.5 Bar,

due to the foreign substance that gets stuck, back-flushing starts automatically, to

wash the foreign substance out, resulting in a minimum filter maintenance

2) Electro-Chlorination / UV Light

Page | 46

Electro-Chlorination

1) Hypo-Chlorite solution, a disinfectant, is injected into main ballast line and then, sterilization process begins. The dosage of disinfectant is controlled by a feedback loop of continuous TRO measurement and flow control valve, to meet the target dose. The Hypo-Chlorite solution kills micro-organisms in a short time.

2) Though, residual oxidant dissipate down, in the tank as time goes, it continues working during the voyage and inhibit the re generation of micro-organisms

3) In the case of de ballasting, thanks to the residual disinfectant in ballast water, additional disinfection of ballast water is not needed.

4) To prevent the marine pollution by the residual disinfectant, the water is neutralized before discharge, by the neutralizing agent injected in front of the ballast pump.

UV Light

1) The residual micro-organisms smaller than 50 microns, which were not filtered, will be killed by ultra violet light by the UV reactor. In proportion to seawater turbidity conditions, the strength of UV light is feedback controlled with UV intensity sensor and the required proportion of disinfection is maintained.

2) Immediately after each ballasting/de ballasting process, CIP unit starts to clean inside of UV reactor, to maintain good performance of UV reactor.

3) For De-ballasting, the water inside the tank is already filtered. Hence, the filter is bypassed. However, for the re treatment of micro-organisms, that re-grow inside the tank during voyage, the ballast water is treated again with UV light, before discharge.

6.3 Ballast Water Profiling

The authors task here was to come up with a Ballast water profile consisting of the

tank capacity, ballast water source (uptake port), exchange and discharge details,

Page | 47

sediment type, sediment size and if these sediments would be able to pass through

the filter while ballasting (uptake of water)

An example is shown below:

Conclusion

Page | 48

In conclusion, the industrial attachment at DNV GL has been a fruitful and

memorable experience. There have been many learning opportunities about the

maritime industry and valuable knowledge/skills gained.

This is definitely an eye opening experience as learning is beyond the boundaries of

coursework at school, giving the author a taste of the real world and how applicable

is what he learnt to the future of the oil and gas, maritime sector

The author would like to express his appreciation to everyone in DNV GL who has

made it possible.

References

Page | 49

https://en.wikipedia.org/wiki/Cost_of_electricity_by_source_-

_Additional_cost_factors

https://www.google.com.sg/search?

q=maintenance+cost+of+diesel+generator&sourceid=ie7&rls=com.microsoft

:en-SG:IE-

Address&ie=&oe=&gfe_rd=cr&ei=KJ3fV_X2DeGq8wfGiYjgBw&gws_rd=

ssl

https://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/

fuel_cell_mhe_cost.pdf

https://en.wikipedia.org/wiki/Power-to-weight_ratio

https://www.elengy.com/en/lng/lng-an-energy-of-the-future.html

http://ww2.eagle.org/content/dam/eagle/publications/2013/

Scrubber_Advisory.pdf

http://www.fathommaritimeintelligence.com/uploads/2/5/3/9/25399626/

scrubber_guide_sample_pages.pdf

http://www.gl-group.com/pdf/GL_MAN_LNG_study_web.pdf

Page | 50

Appendix A

Page | 51