How to Influence Co2

How to Influence CO2

How to Influence CO2 33

Contents

Introduction .................................................................................................3

COP15 ”Hopenhagen” .................................................................................5

The Decision-making ..............................................................................5

The Copenhagen Accord..............................................................................5

The International Maritime Organisation (IMO) ...............................................6

Choice of Engine Power and rpm .................................................................7

Engine Efficiency ..........................................................................................9

Waste Heat Recovery System..................................................................... 10

Turbocharging Layout ................................................................................. 11

LNG and LPG as Fuel ................................................................................ 12

Diesel Engines Burning Biological Oils and Fat ............................................ 13

Green Ship of the Future ............................................................................ 16

Carbon War Room ..................................................................................... 16

Conclusion and Other Measures Discussed to Increase Efficiency ............... 17



Introduction

The purpose of this paper is to turn

focus on CO2 emissions from marine

engine operation. The paper describes

the attention from the world society, the

regulation expected from international

organisations and how we can influ-

ence CO2 emission by means of engine

optimisation, waste heat recovery and

alternative fuels.

MAN Diesel & Turbo is convinced that

CO2 emission will continue to be an im-

portant subject and, eventually, strict

regulations influencing the ship speed

and operation will be introduced.

As illustrated in the paper, a number of

design and application features can be

used to reduce CO2 emissions from the

marine market.

But what is CO2, and why all this sud-

den fuss about CO2 and greenhouse

gasses in general? The reason is that

measurements show that the world

average temperature is changing. CO2

absorbs and emits radiation within the

atmosphere, which then influences the

average temperature of the earth. Sci-

entists and politicians fear that this may

affect the climate in such a way that it

will influence the way of living on earth

drastically. This has caused politicians,

industries and organisations worldwide

to look for ways to decrease human-

caused CO2 emission to prevent this

from happening.

Naturally, produced greenhouse gas,

such as water vapour, is regarded

the most influencing greenhouse gas

with a contribution of 36-72% to the

greenhouse effect, and CO2 influenc-

ing 9-26%. Exact figures are hard to

establish because some of the effect-

ing gasses absorb and emit radiation

at the same frequency as others and,

therefore, are difficult to distinguish

from each other.

Talking about greenhouse gas, global

warming and CO2, Fig. 1 shows the

results of produced CO2 which has an

impact on the CO2 level in the atmos-

phere.

Besides the naturally produced CO2,

the use of fossil fuels constitutes the

other large contributor. Oil, coal and

gas, which millions of years ago were

organic materials exposed to high pres-

sure, consist primarily of carbon releas-

ing energy when reacting with oxygen

to create CO2 and water.

Human-created CO2 and the natural

CO2 balance will be lowered by reduc-

ing the use of fossil fuels.

1. From the atmosphere to the oceans

Approx. 90 Gt/year of CO2 is ex-

changed between the oceans and

the atmosphere. There is a net ab-

sorption in the oceans of approx. 2.2

Gt/year.

2. From human activities to the atmosphere

Burning of fossil fuels: peats, coal, oil

and gas. 7.2 Gt/year in total is emit-

ted to the atmosphere. Some sci-

entists (from GEUS) believe that the

emission may be as high as 22 Gt/

year, which means that the carbon

accumulation is far larger.

3. From the geosphere to the atmosphere

Carbon is released from the sedi-

mentary layers when heating trans-

forms them to crystalline rock (e.g.

silicate rock types such as feldspar).

The carbon is released by volcanic

activity. Approx. 0.1 Gt/year of CO2

is emitted to the atmosphere.

1 2

2

3

5

4

6

Fig. 1: CO2 contributors


4. From the atmosphere to rivers and lakes

(the hydrosphere)

Carbon is drawn out the atmosphere

by weathering/decomposition of

rock. The carbon ends in rivers and

lakes or in the sea. A total of 0.2 Gt/

year is drawn from the atmosphere

to the hydrosphere.

5. From the biosphere to the geosphere

The decomposition of organic mate-

rial transfers about 0.2 Gt/year from

the biosphere to the geosphere. That

is by creation of sediments.

6. From the atmosphere to the biosphere

About 60-62 Gt/year of carbon is ex-

changed between the biosphere and

the atmosphere. This occurs by pho-

tosynthesis and respiration, and pu-

trefaction of organic material. There

is a net absorption in the biosphere

of about 2.5 Gt/year. However, this

could turn, e.g. if the arctic tundra

thaws out, which would result in a

large volume of CH4 being added to

the atmosphere.

Fossil-energy-using machinery used

for power production both inland and

at sea contributes to global carbon

emissions and, therefore, the attention

has also reached the marine industry,

which transports close to 90% of all

goods in the world and which is by far

the most efficient mode of transporta-

tion, see Fig. 2.

The contribution of global carbon emis-

sions from various sources is shown in

Fig. 3. In this picture international ship-

ping is said to constitute 2.7% of all

produced CO2.

A relatively small percentage comes

from the international shipping, but the

shipping industry must without a doubt

contribute and show willingness to re-

duce CO2.

About half of the world's transport of

goods is transported by MAN B&W low

speed engines.

Total worldwide fuel oil consumption for

international shipping is more than 250

million tonnes yearly.

Fig. 2: Distance travelled with 1 tonne cargo releasing 1 kg CO2 in the air

Fig. 3: Global carbon emission from various sources

0 km 20 km 40 km 60 km 80 km 100 km 120 km 140 km

Boing 747

Heavy Truck

Rail – Diesel

Rail – Electric

Container Vessel

Source: NMT, Network for Transport and Environment

International Aviation1.9%International Shipping

2.7%Domestic Shipping

and Fishing0.5% Electricity and Heat

Production35.0%

Other15.3%

Other Energy Industries4.6%

Rail0.5%

Other Transport cost (road)21.3%

Manufacturing industry and construction

21.3%


COP15 ”Hopenhagen”The Decision-making

Copenhagen became the focus of

world attention in December 2009.

Here, the challenge was for scientists

and politicians to agree on a plan to

stop global warming caused by the ac-

cumulating emissions of CO2 (carbon

dioxide) to the atmosphere.

Therefore, 20,000 delegates from

nearly 200 countries met to discuss

and agree on a plan to slow down CO2

emissions in the future.

The words of the international chapter

on shipping describe shipping as the

servant of world trade, which correlates

to the fact that the maritime industry is

the sixth largest emitter of CO2 emis-

sions.

The International Maritime Organisation

(IMO) warned the COP15 delegates

that it is difficult to impose disciplines

on individual vessels, or even some

countries.

Because ships operate across interna-

tional boundaries, owned in one coun-

try and registered in another, IMO wants

a global approach to be followed.

The Copenhagen Accord, the only

politically high-level agreement from

COP15, makes no mention of the ship-

ping and aviation sectors, so the direc-

tion is not yet decided.

As long as the attention is on CO2

emissions, increasing average tem-

peratures, ice melting climate changes,

flooding, hurricanes, etc., there will be

worldwide efforts to introduce emission

regulations.

The COP15 was organised under the

United Nations Framework Convention

on Climate Change (UNFCCC).

The final draft from COP15 did not in-

clude a defined emission reduction tar-

get for shipping and aviation, despite

a heavy pressure from the European

Union (EU).

At present, it is unclear whether a tar-

get will be set by the UNFCCC or by the

IMO. A Norwegian proposal, supported

by the US, Canada, Japan and, poten-

tially, Australia, wanted to mention spe-

cific targets in Copenhagen, instead of

calling them ”ambitious” medium, long

term goals to be set by the IMO, and its

aviation equivalent.

The Copenhagen Accord

The Copenhagen Accord, see Fig. 4,

is a broad declaration on the climate,

which was joined by 188 countries

worldwide. However, the following five

countries, Sudan, Venezuela, Cuba,

Nicaragua and Bolivia chose not to join

the declaration.

The Copenhagen Accord recognises

climate change as one of the greatest

challenges of our time and, furthermore,

that major cuts in global CO2 emissions

are necessary in accordance with sci-

entific recommendations. The objective

is to stop global warming and stabilise

the increase in global temperature at

below 2 degrees Celsius throughout

this century. The declaration does not

mention specific targets for reducing

CO2 emissions, neither medium term,

Fig. 4: The Copenhagen Accord


nor long term. However, the declaration

lists voluntary CO2 reductions to which

a number of countries have committed

themselves.

The Copenhagen Accord does not de-

scribe anything concrete regarding the

shipping industry. However, the text

does not include anything that stops

the IMO efforts on cutting CO2 emis-

sions, and the Danish Maritime Author-

ity expects that these efforts will con-

tinue. The Copenhagen Accord has a

broader range than the Kyoto Protocol

in that the big nations USA and China

have also joined the declaration, which

can have a positive effect on the nego-

tiations in the IMO MEPC (Marine Envi-

ronment Protection Committee).

The Danish Maritime Authority supports

the ongoing work of IMO to reduce CO2

emissions by means of globally en-

forced IMO regulations.

The International Maritime Organisation (IMO)

IMO is the specialised agency under

the United Nations that prepares the

applicable regulations for the marine

industry. The organisation sets interna-

tional standards for the shipping indus-

try that can be accepted and adopted

by all its members.

IMO’s main task is to develop and

maintain a comprehensive and regula-

tory framework for the shipping indus-

try, and its remit today includes safety

and environmental areas, legal matters,

technical cooperation, maritime secu-

rity, and the efficiency of shipping.

IMO represents 169 member states.

Committees and sub-committees con-

duct the technical work to update ex-

isting legislation or development, and

adopt new regulations. Meetings are at-

tended by maritime experts from mem-

ber states, and interested government

and non-government organisations.

The regulations in use for the Preven-

tion of Air Pollution from ships, IMO

MARPOL 73/78: Annex VI and the

NOx Technical Code have been in force

since January 2000.

However, this regulation does not ad-

dress CO2 emissions from ships.

Therefore, IMO is to undertake the

study of CO2 emissions from ships, in

cooperation with the UNFCCC, with the

objective of establishing amounts and

relative percentages of CO2 emissions

from ships as part of the global inven-

tory. The study should estimate emis-

sions for the most recent years and

address how shipboard emissions and

their relative percentage contribution to

global CO2 levels can be changed in

the future.

The status for this work is that a design

index and an operational indicator have

been developed as tools for quantifying

and optimising of design and operation

for reduction of CO2 emissions.

The purpose of the design index, also

called the Energy Efficiency Design In-

dex (EEDI) is first of all to reduce green-

house gasses (CO2) emitted from ships,

but also to stimulate the development

of energy-efficient ships.

As such, the EEDI index describes the

CO2 emission from a ship while com-

paring it with its benefits, e.g. cargo

transported and distance moved.

The baseline for the calculations is from

several types of existing ships where

the ship design, deadweight, passen-

gers or tonnage are some of the pa-

rameters.

Future regulations from IMO will then

specify a reduction in the EEDI index

for new ships based on these baseline

values.

Below is listed a number of EEDI index

reductions scheduled:

1. lowering of ship speed

2. use of higher efficiency, e.g. waste

heat recovery

3. derating of engines

4. use of LPG or LNG

5. optimisation of the hull

6. optimisation of the propeller

7. coating.

Status of the EEDI: The community is

asked to evaluate the EEDI formulas for

different types and sizes of vessels. The

basic construction of the formula and

the baselines are now fixed, but indi-

vidual coefficients are still evaluated.

The second tool is the operational in-

dex, also referred to as the Energy Ef-

ficiency Operational Indicator (EEOI) – a

tool to evaluate the operational behav-

iour of efficiency onboard.


The objective of the EEOI is:

� measurement of the energy efficien-

cy during each voyage

� evaluation of the operational perfor-

mance by owners or operators

� continued monitoring of individual

ships

� evaluation of any changes made to

the ship or its operation.

In principle, the coverage of EEOI

should include all new and existing

ships engaged in transportation.

The status of EEOI is that it has been

implemented on a trial basis since

2005.

For the moment, it is being used on a

voluntary basis by some owners and

operators to collect information on the

outcome and experience in applying

the EEOI.

IMO objectives:

1. that UNFCCC parties continue en-

trusting IMO with the regulation of

greenhouse gas emissions from in-

ternational shipping, and

2. that the subsequent IMO regula-

tory regime is applied to all ships,

regardless of the flag they fly. IMO

represents all countries – this is the

opinion of the industialised coun-

tries.

Choice of Engine Power and rpm

The layout of the propeller and the en-

gine is essential for the highest possi-

ble efficiency of the main engine and,

thereby, the efficiency of ship propul-

sion.

The derating of the engine, the increase

of the propeller diameter and use of

electronically controlled engines are

described in this chapter.

In general, the larger the propeller di-

ameter, the higher the propeller efficien-

cy and the lower the optimum propeller

speed referring to an optimum ratio of

the propeller pitch and propeller diam-

eter.

When increasing the propeller pitch

for a given propeller diameter, the cor-

responding propeller speed may be

reduced and the efficiency will also be

slightly reduced, but of course depend-

ing on the degree of the changed pitch.

The same is valid for a reduced pitch,

but here the propeller speed may in-

crease.

Major Propeller and Main Engine

Parameters

The efficiency of a two-stroke main en-

gine particularly depends on the ratio of

the maximum (firing) pressure and the

mean effective pressure. The higher the

ratio, the higher the engine efficiency,

i.e. the lower the Specific Fuel Oil Con-

sumption (SFOC).

Furthermore, the larger the stroke/bore

ratio of a two-stroke engine, the higher

the engine efficiency. This means, for

example, that a long-stroke engine type,

e.g. an S80ME-C9, will have a higher

efficiency compared with a short-stroke

engine type, e.g. a K80ME-C9.

The latest considerations on engine

programme layout have therefore in-

cluded an investigation of whether an

even larger stroke/bore ratio than for

the S-type engines would be demand-

ed by the market, when considering the

possible and most optimal future ship

hull designs. This investigation is cur-

rently ongoing.


Compared with a camshaft (mechani-

cally) controlled engine, an electronical-

ly controlled engine has more param-

eters that can be adjusted during the

engine operation in service. This means

that the ME/ME-C engine types, com-

pared with the MC/MC-C engine types,

have a relatively higher engine efficien-

cy under low-NOx IMO Tier II operation.

When the design ship speed is re-

duced, the corresponding propulsion

power and propeller speed will also be

reduced, which again may have an in-

fluence on the above-described propel-

ler and main engine parameters.

The following is a summary of the major

parameters described, see also Figs. 5

and 6.

Propeller

Larger propeller diameter involving:

� Higher propeller efficiency

� Lower optimum propeller speed

(rpm)

� Lower number of propeller blades

involving:

� Slightly higher propeller efficiency

� Increased optimum propeller speed

(rpm) (from 6 to 5 blades means ap-

proximately 10% higher rpm)

Main engine

Increased pmax/pmep pressure ratio in-

volving:

� Higher engine efficiency (e.g. by de-

rating)

Fig. 5: Relative fuel consumption in normal service of different derated main engines for a 75,000-dwt Panamax product tanker operating at 15.1 knots

Alt. 1: 5S60MCC8 nominal (Basis) SMCR=11,900 kW at 105 r/min

Alt. 2: 6S60MCC8 derated SMCR=11,900 kW at 105 r/min

Alt. 3: 6S60MCC8 derated SMCR=11,680 kW at 98.7 r/min

Alt. 4: 6S60MEC8 derated SMCR=11,680 kW at 98.7 r/min

M1

M2M3M4

25

30

35

40

45

50

65 70 75 80 85 90 95 100 %SMCREngine shaft power

Fuel consumptionper day

t/24h

Reduced fuel consumption by deratingIMO Tier ll compliance

Average service load80% SMCR

Reduction () of fuel consumption:

Total Total Propeller Engine

t/24h % % %

0.00 0.0 0.0 0.0

1.14 2.9 0.0 2.9

1.60 4.1 1.8 2.3

2.39 6.1 1.8 4.3

Fig. 6: Relative fuel consumption per day of different main engines for different design ship speeds of an 8,000-teu Post-Panamax container vessel

100

150

200

250

300

22.5 23.0 23.5 24.00 24.5 25.0 25.5 26.0 26.5 knDesign ship speed

t/24hkg/24h/teu

15

20

25

30

35

Fuel consumption per day

50

60

70

80

90

100% Reference

110

120

130

%

Relative fuelconsumptionper day

Fuel consumption per dayIMO Tier ll compliance

26.0 kn

25.0 kn

23.0 kn

Fuel reduction () per day:

Ship speed 37.4%

Propeller 1.3%

Engine 2.3%

Total: 41.0%

80% SMCR90% SMCREngine service load

70% SMCR

9S90MEC8SMCR=43,100 kW × 78.0 r/min

10K98ME7SMCR=60,000kW × 97.0 r/min

12K98MEC7SMCR=69,800kW × 102.1 r/min


Larger stroke/bore ratio involving:

� Higher engine efficiency (e.g. S-type

engines have higher efficiency com-

pared with K-type engines)

Use of electronically controlled engine

instead of camshaft controlled:

� Higher engine efficiency (improved

control of NOx emissions).

Case 1: 75,000 dwt Panamax Product

Tanker at 15.1 knots ship speed

Nominally rated 5S60MC-C8 versus

derated 6S60MC-C8 and 6S60ME-C8

� Influence of derating of engine

� Influence of derating and increased

propeller diameter

� Influence of using electronically con-

trolled engine

Case 2: 8,000 teu Post-Panamax Con-

tainer Vessel at reduced ship speed

Derated 9S90ME-C8 versus 10K98ME7

and 12K98ME-C7

� Influence of reduced ship speed

� Influence of increased propeller

diameter.

Engine Efficiency

The relationship between engine effi-

ciency and CO2 in the exhaust gas is

directly linked. When the carbon in the

fuel is burned, the C and O2 will form

the CO2 and, therefore, the CO2 emis-

sion ratio is primarily determined by fuel

consumption and the fuel composition,

the latter being rather constant for fossil

fuels: CO2 approx. 3,200 g/kg of fuel,

based on 86% carbon in fuels.

This means that the higher the engine

and plant efficiency, the lower the CO2

level.

If we look at different types of prime

movers, see Fig. 7, it is obvious that the

modern diesel engine is the most effi-

cient machinery used as prime mover

today.

If we then look into the development of

the engine since 1950, Fig. 8 shows a

huge development of the engine effi-

ciency, bringing it close to the so-called

Carnot efficiency.

Because the thermal energy is convert-

ed into mechanical work in an engine

cycle, it can be shown that the maxi-

mum efficiency possible is obtained if

the cycle is reversible (that the process

can come back to where it started).

30

20

40

100 %

10

60

50 Medium-speed diesel

0 Load

50

% Thermal efficiencies

Gas turbine

Combined cycle gas turbine

Steam turbine

Low-speed diesel

Fig. 7: Different prime mover types

Year

SFOC g/kWh

Ideal Carnot cycle

Full-ratedDe-rated

84VT2BF180K98FF

KGF

GB/GBEGFCA

NOx

NOx

g/kWh

SFOC

0

50

100

150

200

250

1940 1960 1980 2000 2020

10

20

2007

3.4ME/ME-C/ME-BMC/MC-C

Fig. 8: Engine efficiency development


And further that only a reversible pro-

cess has the same maximum efficiency.

A well-known and much used example

of such a cycle is the Carnot process.

Calculations and measurements have

shown that we are close to the high-

est efficiency possible, according to

the Carnot process, with the standard

engine design available today, without

extra equipment.

This also means that if we want to in-

crease the engine efficiency and, there-

by, reduce the CO2 content, we need to

look for other methods and techniques

used in connection with the application

of diesel engines.

Waste Heat Recovery System

The most efficient way to increase the

total efficiency of a ship with a two-

stroke engine is to utilise the waste

heat of the engine.

Waste heat is collected primarily from

the heat energy of the engine exhaust

gas. Technology with power turbines,

i.e. steam turbines in combination

with high-efficiency turbochargers and

boilers, has already shown system ef-

ficiencies of 55%. This corresponds to

a 10% increase in efficiency and 10%

lower fuel consumption and CO2 emis-

sion. The highest theoretical efficiency

is close to 60%.

If waste heat recovery is combined

with NOx reduction methods and SAM

(scavenging air moisturisation) or EGR

(exhaust gas recirculation), the total ef-

ficiency can be raised to 57% and 58%,

respectively. Corresponding to 14%

and 18% of engine efficiency.

A number of ships, though limited, have

been built with such systems over the

past 25 years. Shipowners’ interest in

WHR systems has so far been depend-

ing on the cost of HFO, the expecta-

tions to the development in the cost of

HFO and, furthermore, the willingness

of the shipyards to deliver ships de-

signed and built for the WHR concept.

Experience has shown that the reli-

ability of the system can be high, but

installation is complicated, and space

for extra equipment is required, and

the equipment requires maintenance.

These are all important factors that the

operators take into account when or-

dering a new ship.

Superheated steam

TG

Generator PT

Switchboard

Diesel generators

Exhaust gas receiver

Main engine

Shaft/motorgenerator

EmergencygeneratorTG: Turbogenerator

PT: Power turbineTC: TurbochargerSaturated

steam for heating purposes

Exh. Gas boiler

TC

Fig. 9: Thermo efficiency system

Fig. 10: Waste heat recovery

Steam turbine

Generator Power turbine


If we make a parallel to the two-stroke

power stations, a number of plants

have either steam turbines, power tur-

bines or both, but the power station in-

dustry calculates with longer payback

times for the equipment, and has un-

limited space, see Figs. 9 and 10.

The question is what effect the future

regulation of CO2 will have on the adop-

tion rate of the WHR system in the ma-

rine industry.

Turbocharging Layout

The well-known influence on engine

efficiency from the turbocharger also

makes the design, layout and applica-

tion of turbochargers essential.

With the following four technologies,

potential for increases in energy effi-

ciency at reduced load exists. All four

technologies are proven and available:

� Exhaust gas bypass (EGB)

� Variable turbine area

� Turbocharger cut-out

� Sequential turbocharging, see Figs.

11 and 12

Turbocharger cut-out can also be made

for engines with two and four turbo-

chargers.

SFOC g/kWh

Engine load %

164165166167168169170171172173174175176177178179180181182183

0 10 20 30 40 50 60 70 80 90 100 110

10K98ME6-TII with 3 x TCA88-21SMCR: 57,200 kW at 94.0 RPMOpt. point: 100.0 % IMO NOx Tier II comp.

10K98ME7-TII with 3 x TCA88-21SMCR: 57,200 kW at 97.0 RPMOpt. point: 100.0 % IMO NOx Tier II comp.

10K98ME7-TII with 3 x TCA88-21SMCR: 57,200 kW at 97.0 RPMOpt. point: 100.0 % IMO NOx Tier II comp. +Exhaust Gas By-pass

Fig. 11: Low-load layout with exhaust gas bypass

Fig. 12: Turbocharger layout or charge air tuning

162.0

164.0

166.0

168.0

170.0

172.0

174.0

176.0

178.0

180.0

25 35 45 55 65 75 85 95 105

Basis EGB ME2 VTA TC cut 1/3Load %

SFOC g/kWh


LNG and LPG as Fuel

The electronically controlled ME-GI

high-pressure gas injection engine was

introduced some years ago, primarily to

the LNG market. The ME-GI engine is

designed to burn the boil-off gas evap-

orating from the liquefied gas in the

LNG storage tanks onboard. Today, we

see much wider application potential

for the ME-GI engine.

Existing and future expanded emission

control areas (ECA) call for the use of

low-sulphur fuels within 200 nautical

miles from the coast. And with the cur-

rent low price of LNG combined with

the operational flexibility of the ME-

GI engine, it is our expectation that a

broad range of vessels in the merchant

fleet will be ordered with an ME-GI pro-

pulsion plant in the future.

The emission control areas need to be

introduced through IMO.

Fig. 13 illustrates a container vessel.

Operation on gas, not only reduces SOx

and NOx emissions significantly, but

also CO2. Both LPG and LNG are low-

carbon emitting hydrocarbon fuels, and

the resulting CO2 emission per kWh is

approx. 20% lower than for HFO, and

approx. 30% lower than for coal, see

Table 1.

As a result of the increased global inter-

est for the ME-GI engine, we will at the

beginning of 2011 demonstrate our test

engine in Copenhagen as a 4T50ME-GI

engine.

As part of the development plan, we

have also developed an ME-GI test rig,

where we are testing further develop-

ment and optimisation of the ME-GI

technology towards high efficiency,

high reliability or reduced emission.

Also targets as lower pilot oil amount

and lower minimum load for gas opera-

tion is considered in the optimisation.

The gas supply system is an essential

component for gas operation. Thor-

ough investigations in cooperation with

suppliers, classification societies, yards

and engine builders have therefore

been ongoing for a number of years.

Today, we can show cryogenic pumps

pumping liquid gas through an evapo-

rator to the engine, and gas compres-

sors compressing NG to the engine at

the pressure needed. These systems

have gained successful experience with

regard to safety, reliability and availabil-

ity.

During the demonstration and perfor-

mance optimisation on our research

engine, DSME will supply and dem-

onstrate their cryogenic liquid natural

gas pump, evaporator and gas supply

control. Fig. 13 illustrates the unit that

will be delivered by end-2010 to be in-

stalled at the MAN Diesel & Turbo re-

search facilities in Copenhagen.

Fig. 13: Gas as fuel on board container vessels

Main Engine ME-GI

• IHI type B tanks low pressure tanks, BOR 0.2 %/day

• TGE type C tanks 4-9 barg pressure (up till 50 travelling days) BOR 0.21 - 0.23 %/day

Containment systems for LNG

LNG fuel supply system


A demonstration will be arranged of the

4T50ME-GI in 2011 for class societies,

customers and licensees of MAN B&W

low speed two-stroke engines, see Fig.

14.

Diesel Engines Burning Biological Oils and Fat

The motivation to consider biofuels and

fat as fuel is based on the objective to

reduce greenhouse gas (CO2) emis-

sions and use renewable and green

energy sources instead of depleting the

limited fossil fuel available.

Today, biofuel and fat are used on a

number of medium and low speed

power plants worldwide.

The combustion of biofuel instead of

mineral fuel results in a net-reduction

of greenhouse gas emissions and other

combustion-related pollutants, while at

the same time allowing for appropriate

disposal of the waste biological oils of

residential, commercial and industrial

origin.

Emission comparison

S50ME-C8-GI engine compared with the equivalent ME or MC type engine 48% propane and 48% butane and 5% pilot oil compared with HFO operation (3.5% sulphur)

Load %

SFOC g/kWh

Pilot oil %

Gas %

CO2

ME/MC ME-C8-GI g/kWh g/kWh

SOx

ME/MC ME-C8-GI g/kWh g/kWh

NOx Tier II ME/MC ME-C8-GI g/kWh g/kWh

100% 170 5 95 559 472 12 0.60 13.5 11.9

75% 166 7 93 546 461 12 0.78 14.7 12.9

50% 179 10 90 557 470 12 1.19 14.5 12.7

IMO NOx cycle: 14.4 12.9

NOx from fuelbound nitrogen not included in estimated NOx values Actual emissions may deviate due to actual optimisation of engine

Table 1: Comparison of emissions from an HFO burning and a gas burning S50ME-GI type of engine

2) Test on rig

3) Test on R&D engine 4) First production engineVerification test and TAT

1) Design and Calculation

Fig. 14: ME-GI development plan


The design and construction of medi-

um and low speed diesel engines from

MAN Diesel & Turbo allows them to op-

erate on some low-quality liquid fuels

such as crude vegetable oils and some

waste and recycled biofuel, which is

also considered the cheapest biofuel

available.

The possibility of combining sound eco-

nomics with superior eco-friendliness

in the operation of a prime mover has

led MAN Diesel & Turbo to initiate the

development and optimisation of liquid

biofuel combustion on low speed MAN

B&W diesel engines.

Today, biological oil and fat is used on

some power stations where logistics

makes it convenient, and often the

price of the biofuel is set politically.

The expected world consumption of

HFO in the marine market today is ap-

prox. 250 million tonnes per year. It is

not expected that the biofuel will ever

fully replace mineral and fossil fuels,

but it could be a supplement to HFO

and gas, and an alternative to the use

of high-priced distillate fuels in IMO and

locally designated emission control ar-

eas (ECA).

A number of tests involving use of liquid

biofuel and fat have been performed

since the mid-1990s. Tests of rapeseed

oil, palm oil, fish oil, frying fat and fat

from slaughterhouses have been per-

formed on three different occasions at

MAN Diesel & Turbo.

Today, a number of medium and low

speed plants are in operation in Eu-

rope, all with good service experience.

For comparison, Table 2 shows the fuel

spec. of different biofuels and the HFO

specification. As can be seen the bio-

fuels and distillates are close in com-

parison.

The most common biofuels are illus-

trated in Fig. 15.

The MAN Diesel & Turbo reference lists

include seven MAN B&W two-stroke

low speed engines – some still under

construction – and more than 30 MAN

four-stroke medium speed engine

plants sold for operation on biological

oils and fat. Most of the engines on the

reference lists have logged thousands

of hours in operation on, respectively,

cooking oil, palm oil, soy rapeseed and

castor beans, see Fig. 16.

The conclusion from using biofuels and

fat is the following:

� the use matches the minimum MAN

Diesel & Turbo fuel specification

� no important deviation in diesel com-

bustion process and heat release

� no important deviation in fuel injec-

tion pattern

� no important deviation in engine per-

formance

� no change in engine efficiency

� redesign of fuel injection equipment

allows 5 and 15 TAN, respectively.

Vegetable oil treated,

non transesterified

Bio Diesel EN 14214 Marine diesel ISO 8217

DMB

Heavy Fuel Oil ISO

8217 RM

Density/15 °C 920 - 960 kg/m³ 860 - 900 kg/m³ < 900 kg/m³ 975 - 1010 kg/m³

Viscosity at 40 °C/ 50 °C

30 - 40 cSt 3.5 – 5 cSt < 11 cSt < 700 cSt /50 °C

Flashpoint > 60 °C > 120 °C > 60 °C > 60 °C

Cetane no. > 40 > 51 > 35 > 20

Ash content < 0.01 % < 0.01 % < 0.01 % < 0.2 %

Water content < 500 ppm < 500 ppm < 300 ppm < 5 000 ppm

Acid no. (TAN) < 4 < 0.5 - -

Sulphur content < 10 ppm < 10 ppm < 20 000 ppm < 50 000 ppm

Calorific value approx. 37 MJ/kg approx. 37.5 MJ/kg approx. 42 MJ/kg approx. 40 MJ/kg

Table 2: Comparison of fuel characteristics


A common practise that is expected

in the industry if distillates become the

dominant fuel in ECA areas is that even

more biofuels will be blended in the dis-

tillates used for marine application.

According to the ISO 8217 marine fuel

standard, it is not acceptable to blend

biofuels or any other non-fossil fuel

product into the fuel oil. However, this

already occurs today, and the biofuel is

typically added for political or economi-

cal reasons, and it is expected that ISO

8217 will need to include this in com-

ing standards. There are thorough con-

siderations to be made when biofuel is

mixed into marine fuels.

Compatibility issues concern whether

the fuel is mixable and the possibility for

introducing biological bacteria.

Palm Oil

Castor Bean

Rape Seed

Soy Consistsof 40 – 50%usable Oil

Fig. 15: Sources of biofuels

Fig. 16: The 7L35MC-S plant at Brake


Green Ship of the Future

A group of maritime companies, A. P.

Møller-Mærsk, MAN Diesel & Turbo and

Odense Steel Shipyard, have set up a

task force to develop and demonstrate

green technologies within shipping and

shipbuilding.

The goal of the Green Ship of the Fu-

ture is to develop strategies to reduce

CO2 by 30%, SOx by 90%, NOx by 90%

and particulate emissions, both from

ships in service and from newbuildings,

see Fig. 17.

All Danish companies and organisa-

tions that are able to demonstrate a

technology with potential for reduction

of emissions from machinery, propul-

sion, operation and logistics are wel-

come to join.

Many fields of knowledge are involved,

such as systems for recycling of heat

energy, optimisation of the hull, propel-

lers and rudders as well as optimisation

of the draft and speed for a given route

and arrival time, and fouling of the hull

and propeller.

MAN Diesel & Turbo contributes with

technologies such as EGR (exhaust gas

recirculation), water in fuel (WIF), waste

heat recovery system, autotuning and

general genset and engine optimisa-

tion. Furthermore, MAN Diesel & Turbo

also cooperates with Aalborg Industries

on the testing of a full flow scrubber.

The Danish Shipowners Association

believes that the merchant fleet will be

able to increase its efficiency by at least

15% by 2020.

Carbon War Room

The organisation called the Carbon War

Room is an NGO organisation that was

launched by, among others, the CEO

and founder of Virgin Air, Richard Bran-

son.

MAN Diesel & Turbo’s first contact with

the organisation was at a reception at A.

P. Møller-Mærsk (APM) in Copenhagen

in connection with the COP15 meeting.

On that occasion, Richard Branson,

José Maria Figueres (former president

of Costa Rica) and Niels Smedegaard

Andersen, CEO of APM, spoke of how

the efforts to cut CO2 emissions may

go hand in hand with new business op-

portunities if traditional barriers in the

shipping industry are removed.

If the Carbon War Room can initiate

and contribute to new solutions and

change ways of application, it will ease

CO2 / Fuelconsumption

reduction systems

NOx/SOx reduction systems

EGR system installed

50% NOx reduction

SAM & WIF

60% NOx reduction

SCR and Exhaust gas scrubber

90% NOx reduction

90% SOx reduction

WHR system installed

12% CO2/ fuel reduction

up to 20% when combined with SAM/WIF

Pump & auxiliary system optimisation


Dual/Multi MCR ratings


Automated Engine Control

1% CO2 / fuel reduction

Open cooperationDemonstration projects identified for Climate summit in Copenhagen 2009

Fig. 17: The green ship of the future – 2012


the introduction and effect of the CO2

reduction method. Methods that can

be both practical and applicable with-

out spoiling the safety and reliability re-

quired in the people and goods trans-

portation sector.

The Carbon War Room organisation

has just been created, and it is ex-

pected that many more people and or-

ganisations will be involved in the near

future.

Conclusion and Other Measures Discussed to Increase Efficiency

Many technologies are available in the

market to, in some way, reduce CO2

emissions from the use of fossil fuels.

Some things are outside the influence

of MAN Diesel & Turbo and our licen-

sees, and are more controlled by the

shipowners and requirements from the

authorities.

One method is the air friction technolo-

gy, which reduces the friction between

the steel hull bottom and the water by

introducing a layer of air between the

hull and the water. The air will be lo-

cated in a narrow hollow in the specially

designed hull bottom.

The air could be produced by the high-

efficient turbocharger on the main en-

gine or by a separate air compressor.

In principle, wind can provide propul-

sion energy to supplement conventional

fuel. The German company Sky Sail is

probably the most advanced of a num-

ber of companies looking, once again,

to harness the wind for ship power. Its

kite-based wind assistance system has

been tested on several installations and

has achieved most encouraging results

with most of the recent developments

concentrating on the computerised

control and launching system, integrat-

ing the deck components into one sin-

gle unit.

The kite-based wind assistance is not

suitable for all ship types and routes.

But there might be a fuel saving and

CO2 reduction potential for vessels reg-

ularly travelling routes with a favourable

profile of prevailing winds.

The engine speed has a huge impact

on the use of power and, thereby, also

CO2 emissions. If the authorities wish to

restrict the acceptable level of speed for

the different types of merchant ships,

it will influence the size of engines, but

expectedly also increase the number of

ships needed in the world.

In Fig. 18, we have shown two exam-

ples of the ship speed’s influence on

the power needed.

Large container ship Propulsion power needed

25 knots refers to 100% relative propulsion power A reduction of 5 knots will result in 38% propulsion power requirement, or 48% fuel consumption per journey.

Reduced fuel oil consumption Reduced exhaust emissions Optimised cargo capacity in fleet

Fig. 18: Power vs. ship speed


Fuel:Fuel consumption [kg/MWh] 180 182 171Fuel LHV [kJ/kg] 40,500 40,500 42,619Carbon content [kg CO2/kg fuel] 3.16 3.16 3.15Sulfur content [% S (w/w)] 2.7 2.7 0.1

kg CO2/MWh:Generated by the engine 570 574 540Released from sea water 9 13 0Desulphurisation of heavy fuel oil 0 0 68

Total 579 588 609- Reference 579 579 579Additional CO2 [%] 0 1.4 5.1

No

abat

emen

t

Scr

ubbi

ng (S

W)

Dis

tilla

te

Assumptions:Engine fuel efficiency 49.3 %Additional fuel consumption due to scrubber 0.75 %Additional CO2 due to desulphurisation of HFO 12 %SO2 disposed at land 30 %S to CO2 conversion factor in sea water 2 mol CO2 /mol SO2 (worst case)

Fig. 19: CO2 used for production of distillate

When comparing the scrubbing of HFO

and the use of distillates even the re-

finery process is investigated. As such,

Fig. 19 shows data received from Aal-

borg Industries of the CO2 used for pro-

duction of distillate, compared with the

CO2 used for HFO scrubbing operation.

This means that the use of distillates

and limits, or avoid HFO in 2020, might

not be the right solution when consid-

ering the overall CO2 emissions.

Singapore-based Ecospec claims to

be able to remove 77% of CO2, 66%

of NOx, and 99% of SOx by means of

exhaust gas aftertreatment. Results

that could give a huge contribution to

exhaust gas emission reduction.

So far, MAN Diesel & Turbo has dis-

cussed the technique used with

Ecospec to understand the chemical

reaction and energy amount used, but

we still need to see the process work-

ing as promised, fulfilling the emission

reductions.

Another technique investigated from

many parts of the industry is CO2 stor-

age. This concept is based on carbon

capture and storage (CCS).

Carbon captured mainly from land-

based power stations, gas processing

and oil refineries and stored in the un-

derground storage is still only a blue-

print. Ultimately, it will be politics and

economy that determine when CCS

can be realised, and when it does, a

huge potential for CO2 transporting

ships is expected, giving a new market

potential for engines and ships.

Maersk Tankers estimate a potential

demand for 380 ships in the North Sea

alone.

Technically, CO2 is double the density

of liquefied petroleum gas, and will be

able to carry double the amount of CO2

compared with LPG.

The point is that there are many spe-

cialists with different views on the influ-

ence of CO2 and the trade-off for other

emissions.

The final decision is taken by politi-

cians, but in the end it is important that

MAN Diesel & Turbo and our licensees

influence the decisions that are made

and support the most optimal solutions

for the environment and still practical

for marine applications.

As a member and advisor, MAN Die-

sel & Turbo participates in the debate

in Euromot, IMO, CIMAC, EPA, CARB,

etc., to provide our expertise and influ-

ence the decisions to be made so that

optimal solutions are found.

By this paper, we hope to have en-

lightened you on MAN Diesel & Turbo’s

technical considerations and expecta-

tions to the possibilities of influencing

the emission of CO2.

MAN Diesel & TurboTeglholmsgade 412450 Copenhagen SV, DenmarkPhone +45 33 85 11 00Fax +45 33 85 10 [email protected]

MAN Diesel & Turbo – a member of the MAN Group

All data provided in this document is non-binding. This data serves informational purposes only and is especially not guaranteed in any way. Depending on the subsequent specific individual projects, the relevant data may be subject to changes and will be assessed and determined individually for each project. This will depend on the particular characteristics of each individual project, especially specific site and operational conditions. Copyright © MAN Diesel & Turbo. 5510-0083-01ppr Aug 2014 Printed in Denmark

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How to Influence Co2