Green Car Congress: Study Finds Biodiesel Blends with Marine Fuel Can Improve Thermal Efficiency and Reduce CO Emissions; NOx and CO2 Emissions Increase

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Study Finds Biodiesel Blends with Marine Fuel Can Improve Thermal Efficiency and Reduce CO Emissions; NOx and CO2 Emissions Increase

30 December 2008

Brake thermal efficiency (top) and fuel consumption (bottom) of 100% biodiesel, 100% marine fuel, and three biodiesel-marine fuel blends. Click to enlarge. Adopted from Gökalp (2008), Credit: ACS

Blending biodiesel with marine fuel can improve the brake thermal efficiency (BTE) of a diesel engine and reduce CO emissions, although it increases fuel consumption, according to a study by researchers at Sakarya University and Kocaeli University in Turkey. Use of biodiesel increased NO_x emissions and slightly increased CO₂ emissions (measuring actual CO₂ out, not factoring in the renewable character of the fuel) in the study.

The results were among the findings of a larger study on the effects on emissions characteristics and first- and second-law efficiencies of pure soy biodiesel and three different biodiesel blends with standard No. 2 diesel and marine fuels in a diesel engine. A paper on the work was published online 24 December in the ACS journal Energy & Fuels.

Physical characteristics of test fuels
Fuel property	ASTM Method	Diesel	SME	Marine Fuel
Density [kg/m³, 15 °C]	D1298	850	881	830
Viscosity [cSt, 40 °C]	D445	2.8	4.173	3.7
LHV [kJ/kg]	D4809	42,640	37,388	44,308
Cetane number	D976	54		45
Cetane number	D613		50
Sulfur [wt %]	D4294	0.38		0.29
Flash point [°C]	D93	74	105	75
Cloud point [°C]	D97	-4		-6
Cloud point [°C]	D2500		-3
Particulate matter [mg/L]	D5452	2		3

The team used a four-cylinder, four-stroke, direct-injection “TZDK Basak” diesel engine that was originally designed for No. 2 diesel. The 3.14L engine has a maximum power output of 40 kW (54 hp) with a compression ratio of 16.8:1. They first tested the engine with 100% diesel (D2), 100% marine fuel (MF) and 100% soybean oil methyl ester (SME). They then tested the engine with 5%, 20% and 50% blends of SME with D2 and 5%, 20% and 50% blends of SME with MF.

NO_x (top), CO (middle) and CO₂ (bottom) results with 100% marine fuel, 100% SME, and three blends. Click to enlarge. Adopted from Gökalp (2008), Credit: ACS

All tests were performed under steady-state conditions. The brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), mechanical efficiency (ME), exhaust gas temperature, and NO_x CO, and CO₂ emissions were investigated.

Among the findings for the marine fuel and marine-biodiesel blend testing were:

Running neat (100%) SME biodiesel yielded maximum values for BTE (the ratio of the power output to the fuel energy input). For all fuels, maximum thermal efficiency is obtained at 1,600 rpm, where the mean fuel consumption is at a minimum.
Because the heating value of SME is lower than both that of diesel and marine fuel, its use increases fuel consumption.
Use of biodiesel at any blend level, increased NO_x emissions. The higher the percentage of biodiesel, the greater the NO_x.
CO emissions decreased with an increasing SME percentage in marine fuel. Biodiesel fuels contain about 11% oxygen by weight, aiding more complete combustion, and causing the formation of CO₂ rather than CO.
Actual CO₂ emissions for biodiesel blends were slightly higher than those from pure marine diesel.

Resources

Burak Gökalp, Hakan S. Soyhan, Halil İ. Saraç, Dilek Bostan and Yonca Şengün (2008) Biodiesel Addition to Standard Diesel Fuels and Marine Fuels Used in a Diesel Engine: Effects on Emission Characteristics and First- and Second-Law Efficiencies. Energy Fuels Article ASAP doi: 10.1021/ef800392q

December 30, 2008 in Biodiesel, Ports and Marine | Permalink | Comments (4) | TrackBack (0)

Comments

So, if the only remaining issue is with NOx - this can be addressed with fuel treatment, mechanics, or a filter converter. Now to expand R&D on algal oil based diesel that can be massively scaled.

Algae has been curiously overlooked for a long while now. Hmmm.

Posted by: sulleny | December 30, 2008 at 01:55 PM

darn nox, unless you love acid rain

Posted by: philmcneal | December 30, 2008 at 08:06 PM

Hmmn Cutting diesel with lighter fractions has been done forever.
It was donen to simply to make cold gunk flow to the marine engine at the cost of lesser energy content and lesser performance as a result.

Some one actually had the audacity to publish this as research?

Reality: the World negotiated and adopted the latest MARPOL Annex VI Tier III and TierIV marine emissions regulations, in 2008. They were in negotiations for three years. That will continue to cleanup marine emissions. Thanks to the novel approach for enforcement proved in the earlier Tier I and /Tier II regulations proved effective. No emisssions certification, no marine insurance, means that even flag of convenience registered ships must (and do) comply.

Thank you EPA and Mr. Bush for your unheralded efforts.

Posted by: ExDemo | January 02, 2009 at 07:50 AM

The majority of air and water pollution exists entirely because of George Bush - I read it at the supermarket.

Posted by: Reel$$ | January 02, 2009 at 09:45 AM