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Workshop on alternative marine fuels “Engine technical adjustmentLENNART HARALDSON 2010 11 16 2010.11.16 Rev. 1 Rev. 1

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Workshop on alternative marine fuels

“Engine technical adjustment” g e tec ca adjust e tLENNART HARALDSON

2010 11 162010.11.16

Rev. 1Rev. 1

Content

1. Gas engines • Combustion influence• Fuel handlingg

2. Low viscosity distillate fuels• Fuel pump behaviourFuel pump behaviour• Performance influence • Fuel incompatibility

3. Bio oils• Approved bio oils

Bi il bi di l• Bio oils vs.bio diesel• Fuel preparation• Fuel characteristics

The driver: new regulations

NOx SOxTier II (2011)Tier III (2016)

Global 3.5% (2012)ECA 0.1% (2015)

Global 0.5%S (2020 or 2025)

COCO2GHG

Under evaluation by IMO

Fuel alternatives in close future

What to choose ?

HFO LFO GASAftertreatment:

ScrubbersSCR

NOx Tier 3compliant engine

+ Low sulphur fuel

Gas as fuel

p

And in the end it all boils down to $$$

Wärtsilä gas engines

1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011

W34DF

W50DF

W20V34SG

W34DF

W220SG

W180SG

W34SG

W28SG

W32DF

W46GD

W25SG

W34SG

GD = Gas Diesel engine

W32GD

gSG = Spark Ignited Gas engineDF = Dual Fuel engine

Gas engine characteristics

Gas-Diesel Duel-Fuel Spark-Ignited

Di l C b ti Ott C b ti Ott C b tiDiesel Combustion(Diffusion Combustion)

+ Not knock sensitive,

Otto Combustion(Premixed Combustion)

+ Tier III (NOx) solution

Otto Combustion(Premixed Combustion)

+ Tier III (NOx) solution,fuel MN not an issue

+ Low THC, CO+ High load acceptance

Tier III (NOx) solution+ Higher ignition energy

than spark plug+ High efficiency (in gas mode)

( )+ No additional fuel

beside gas+ High efficiency

- No Tier III (NOx) solution as is

- Fuel sensitive (knocking), MN>70 no derating

- High THC, CO

- Fuel sensitive (knocking), MN>70 no derating

- High THC, COg- Lower load acceptance

g- Lower load acceptance

Gas consumption

By operating the DF-engine according to propeller curve SFOC and emission reductions will be improved.

Constant Speed Engines Variable Speed Engines

[kJ/

kWh

kJ/k

Wh] Spee

BS

EC

[

BSEC

[k

ed [rpm]

50 75 85 100

BSEC total 6L 9L engines

50 75 85 100

BSEC total 6L 9L engines

Wärtsilä 34DF Wärtsilä 34DF

BSEC total. 6L, 9L engines

BSEC total. 12V, 16V engines

BSEC total. 6L, 9L enginesBSEC total. 12V, 16V enginesSpeed

Wärtsilä 34DF

LNGPac - a solution for LNG fuelled ships

3

1 Storage tanks 6

3

41. Storage tanks

2. Evaporators5

16

3 B k t ti 253. Bunker station

4. Gas valve unit enclosure

2

5. Dual-Fuel Main engine

6. Dual-Fuel Aux engines

Low Sulphur distillate fuels

The use of low sulphur fuel is a primary method t d th SOto reduce the SOx emissions in diesel enginesengines.

Low sulphur heavy fuel p yoils have been in use for some time and the use is

ll d t dwell documented.

If fuels with very lowIf fuels with very low sulphur levels are supplied these are likely pp yto be distillate fuels.

Low viscosity distillate fuel operation

Low flash point:Safety Aspect, Insurance companies can refuse to paycompensation for the damages, e.g. if a fire in an engineroom occurs and a fuel with the flash point of < 60 °Croom occurs and a fuel with the flash point of 60 Chas been used.

Low viscosity:Specified fuel injection viscosities for our engines are:Sulzer 2-s engines: 13 – 17 cStWärtsilä 4-s engines: 16 – 24 cStLS di till t f l t i l 2 St/ 40°CLS distillate fuels typical ~2 cSt/ 40°C

Leakage in the injection system will influence performance !

Compatibility:

Risk of incompatibility of HFO and LFOSpot test - ASTM D 4740 - 95

4

5

HighCompatibility problems are related to the fuel’s stability

2

3

4

Spo

t rat

ing

Moderate

Compatibility problems are related to the fuel s stability reserve. HFOs are rather aromatic and contain asphaltenes.If the stability reserve of such a HFO is low, it cannot stand mixing more paraffinic LFO into it, and as a consequence asphaltenes will precipitate out of the blend.

10 10 20 30 40 50 60 70 80 90 100

% LFO

Low

Source: Fortum

asphaltenes will precipitate out of the blend.

Too low injection viscosity – consequences

Injection equipment Cavitations, wear, seizure. Gas pocket formation in fuel system is also possible consequence.

Engine performance, minor effects

Leakage delay in dynamic injection & prolonged injection period slower heat release reduced cylinder g y y j p g j p ypressure & higher exhaust temperature –> increase in fuel consumption as well as incomplete combustion (increased smoke !!!)

Engine performance, worst case

Vaporisation of lighter fuel fractions, loss of capability to produce full power, stalling, black-out, starting problems fuel leakage into cam boxproblems, fuel leakage into cam box.(Higher risks when pumps are worn)

C bi ti ith l d it f th LS di till t f l i th i kCombination with low density of the LS distillate fuel increase the risk for performance effects !

LS adaption unit

E i t t k it i t l i it f lEquipment to make it easier to run on low viscosity fuels can be obtained as:

Fuel coolers & Fuel chillers to cool down fuel for increase fuel viscosity

Fuel switch equipment to support the switch between HFO & LFO(2°C/ i )(2°C/min.)

Fuel incompatibility

When two different fuels are mixed there is a risk for incompatibilityWhen two different fuels are mixed there is a risk for incompatibility….which may cause

clogging of fuel filtersi d l d tincreased sludge amountsticking of fuel injection pumpsdeposit formation on the engine components

The risk is generally not very high, but incompatibility may occur if two fuels originate fromdifferent crude oils or different refining processes.

I tibilit bl l d i t d t t h bl di f lIncompatibility problems can also occur during steady-state, e.g. when blending fuels.

Mitigationgas much as possible avoid mixing two different fuelsperform a compatibility test onboard before mixing the fuels in questionschedule permitting, make a compatibility test in a laboratory before mixing the fuels in

tiquestion.the size of tanks where different fuels are mixed and duration of the mixing should be minimized. (this requirement is not compatible with the target of minimizing thermal shocks at 2°C/min.))

Liquid Biofuels (LBF)

What are liquid biofuels?

– Liquid biofuels are fuels derived from renewable sources• Vegetable oils/plant oils and their derivatives • Non vegetable oils and fats• Non-vegetable oils and fats • Other liquid fuels derived from renewable raw

material– Wood pyrolysis oilpy y– Bioethanol etc.

– Liquid biofuels are not automatically biodiesel• Biodiesel is defined as non-petroleum-based diesel

fuel consisting of short chain alkyl (methyl or ethyl) esters, made through transesterification of vegetable oil or animal fat ege ab e o o a a a– Other names: FAME, RME, SME etc.

World Production of Oils and Fats 2008

World Production of Oils & Fats 2008160 million tonnes

Palm Oil27%Other

Animal Fats15%

• 2008 Total world production 160 million tonnes (Jatropha oil not

S b OilRapeseed Oil

12%

Vegetable Oils13% Palm Kernel

Oil3%

( pincluded)

• 2008 Total world consumption of mineral crude oil 3927.9 million

Soyabean Oil23%

12%Sunflower Oil

7%tonnes (BP)

Source : Oil World Annual (1999 - 2007) & Oil World Weekly (14 December, 2007).Source : MPOB - For data on Malaysian palm oil and palm kernel oil.Source : BP Statistical Review of World Energy

Wärtsilä LBF Status

Approved Liquid Bio fuels:pp q

All vegetable based oils as well as animal fats as long as they fulfil the Wärtsilä SpecificationWärtsilä Specification Example: Palm oil, rape seed oil, olive oil, soya oil, sunflower oil, jatropha oil,

chicken oil, fish oil etc.

Refined biofuels such as Biodiesels (Transesterified bio oils)

Not Approved:– Wood pyrolysis oils

Eth l– Ethanol– Methanol– DME – Bio oils, alcohol blends

Chemical Compositions

Mineral oils H H H H H H H H H H HI I I I I I I I I I I

Decane (Paraffinic Molecule) Anthracene (Aromatic Molecule)

• Mineral oil based fuels are complex mixtures of different hydrocarbons

H-C-C-C-C-C-C-C-C-C-C-C-HI I I I I I I I I I IH H H H H H H H H H H

Vegetable oils and Animal Fats

• Chemically vegetable oils and animal fats are composed of triglycerides i e glycerolare composed of triglycerides, i.e. glycerol bound to three fatty acid molecules

• Vegetable oils typically contain 10-12 % Rn = Fatty acid

oxygen which enables good combustion properties but a lower calorific value

Triglyceride

Biodiesel

• According to EN 14214 biodiesel is defined as fatty acid methyl esters FAME

Is accepted in most car diesel engines– Is accepted in most car diesel engines – Can replace LFO for Wärtsilä engines (as main, back-up and pilot fuel)

BiodieselProduction

Pl t

Biodiesel (Fatty Acid Alkyl Ester)

Triglycerides(Vegetable Oil or Animal Fat)

PlantTransesterification Glycerol (Glycerine)Methanol or

Ethanol

CH2-OOR1 CH3OH R1-COOCH3 CH2-OHI NaOH (Catalyst) ICH-OOR2 + CH3OH R2-COOCH3 + CH-OH I II I CH2-OOR3 CH3OH R3-COOCH3 CH2-OH

Triglyceride Methanol Fatty Acid GlyerolMethyl Ester(Bi di l)(Biodiesel)

Characteristics of vegetable oils

Ash content – The ash content can vary depending on quality and

production/refining processesInfluence particulate emissions in exhaust gases

Palm Oil 22°C Palm Oil 60°C

– Influence particulate emissions in exhaust gases

Temperature control – (The oil viscosity is temperature dependent– Too cold -> wax formation (solidification of fatty acids )– Too hot -> polymerization (especially in the presence of oxygen)

Phosphorus contentosp o us co te t– Lifetime of DeNOx & OxiCat

Acid numberCan cause corrosion– Can cause corrosion

Lower heating value– The LHV of vegetable oils is typically 10-12 % lower than the LHV

f i l ilS °C S °C of mineral oils– More fuel rack – more stress on fuel injection equipment

Palm Stearin 22°C Palm Stearin 60°C

Liquid Biofuel handling

Acceptable storage period for liquid biofuels can be significantly shorter than storage period specified for fossil fuels. Many biodiesel manufacturers are referring to max. one month storage period After that acidity starts to increase leadingmonth storage period. After that acidity starts to increase leadingto faster oxidation rate of the fuel.

Straight liquid biofuels must not be mixed with fossil fuels, but have to be used as such Mixing of straight liquid biofuel andhave to be used as such. Mixing of straight liquid biofuel and distillate fuel will increase the risk of cavitation in the fuel system, since required fuel temperature before engine is normally 80 - 90 °C. At this temperature light fractions of distillate fuel will already start to evaporatealready start to evaporate.

Mixing of straight liquid biofuel with heavy fuel will increase the risk of biofuel component polymerization leading to formation of gummy deposits since the use of heavy fuel wouldformation of gummy deposits, since the use of heavy fuel would require much higher operating temperature than straight liquid biofuel, i.e. normally above 100 °C in order to achieve a proper injection viscosity.

Renewable biodiesel on the other hand can be mixed with fossil distillate fuel.