Fatty Acid Esters (biodiesel)
When we talk of biodiesel fuels today, we are generally talking about fatty acid methyl esters (FAME). Neat vegetable oils or animal fats as such are not suitable for high-speed diesel engines. Biodiesel esters are usually made in a transesterification process from vegetable oils, such as soy, rapeseed, sunflower, etc. Fossil methanol is typically used as an alcohol in the process, and sodium or potassium hydroxide as a catalyst. Ethanol could be used to produce fatty acid ethyl esters (FAEE). The side-product of the process is glycerol. The process is quite simple and the product can be rather low in cost. The transesterification process is basically limited to oils and fats as feedstocks, and the product is always an ester. Due to certain end-use problems with FAME, the current maximum concentration is limited, e.g. up to 7.0% in the European EN590:2009 specification for diesel fuel. FAME biodiesel generally reduces CO, HC, and PM emissions, but increases NOx emissions.
- Chemical structure
- Legislation and standards
- Density and energy content
- Cold properties
- Cetane number
- Sulfur and trace elements
- Stability and water
- How much FAME can be blended in diesel fuel?
- Compatibility with cars and materials
- Storage and handling
- Engine cleanliness and emission control devices
- Power output, fuel consumption, and CO2
- Regulated emissions
- The NOx dilemma
- Unregulated emissions
- Health and air quality effect
- Cold temperature emissions
IEA AMF work on biodiesel esters:
Aakko, P., Nylund, N-O., Westerholm, M., Marjamäki, M., Moisio, M., Hillamo, R. and Mäkelä, T. (2002) The emissions from heavy-duty engine with and without aftertreatment using selected biofuels. 29th FISITA World Automotive Congress. Helsinki, 2 - 7 June 2002, 16 p. (Results from IEA-AMF Annex XIII).
Aakko, P. and Nylund, N-O. (2003) Particle Emissions at Moderate and Cold Temperatures Using Different Fuels. SAE Technical Paper 2003-01-3285.
Akasa, Y., Suzuki, T., Sakurai, Y. (1997) Exhaust Emissions of a DI Diesel Engine Fueled with Blends of Biodiesel and Low Sulfur Diesel Fuel. SAE Technical Paper 972998.
Bannister, C., Hawley, J., Ali, H., Chuck, C., Price, P., Brown, A. and Pickford, W. (2009) Quantifying effects of biodiesel blend ratio, at varying ambient temperatures, on vehicle performance and emissions. Society of Automotive Engineers. SAE Technical Paper 2009-01-1893.
Bünger, J., Krahl, J., Munack, A., Ruschel, Y., Schröder, O., Emmert, B., Westphal, G., Müller, M., Hallier, E. and Brüning T. (2007) Strong mutagenic effects of diesel engine emissions using vegetable oil as fuel. Archives of Toxicology. Vol. 81, Number 8. 599-603.
Durbin, T., Norbeck, J. M. (2002) Effects of Biodiesel Blends and Arco EC-Diesel on Emissions from Light Heavy-Duty Diesel Vehicles. Environ. Sci. Technol., 1686-1691.
Environmental Protection Agency (EPA), (2002) “A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions,” U.S. EPA Draft Technical Report – EPA 420- P-2-001, October 2002.
Graboski, M.S. and McCormick, R.L. (1998) Combustion of fat and vegetable oil derived fuels in diesel engines. Prog. Energy Combust. Sci., V.24, 125-164.
Grimaldi, C. N., Mariani, F., Postrioti, L. (2001) Performance and Emissions of a Common Rail DI Diesel Engine Using Fossil and Different Bio-Derived Fuels. SAE Technical Paper 2001-01-2017. 9.
Grimaldi, C. N., Postrioti, L., Battistoni, F., Millo, F. (2002) Common Rail HSDI Diesel Engine Combustion and Emissions with Fossil / Bio-Derived Fuel Blends. SAE Technical Paper 2002-01- 0865.
Knothe et al. (1997) http://papers.sae.org/971681 and http://journeytoforever.org/biofuel_library/VegetableOilsKnothe.pdf
Krahl, J., Baum, K., Hackbarth, U., Jeberien, H.-E., Münack, A., Schütt, C., Schröder, O., Walter, N., Bünger, J., Müller, M. and Weigel,A. (2001) Gaseous Compounds, Ozone Precursors, Particle Number and Particle Size Distributions, and Mutagenic Effects due to Biodiesel. American Society of Agricultural Engineers,. Vol. 44(2).179-191. 17.
Lang et al. (2001) Bioresource Technology 80(2001) 53-62 http://www.ncbi.nlm.nih.gov/pubmed/11554602
McCormick, R., Graboski, M., Alleman, T. and Herring, A. (2001) Impact of Biodiesel Source Material and Chemical Structure on Emissions of Criteria Pollutants from a Heavy-Duty Engine Colorado Institute for Fuels and Engine. Environ. Sci. Technol. 2001, 35, 1742-1747.
McCormick, R. L. et al, (2005) “Regulated emissions from Biodiesel Tested in Heavy-Duty Engines Meeting 2004 Emission Standards,” SAE paper # 2005-01-2200, Society of Automotive Engineers, May 2005. McCormick, R. L., (2005) “Effects of Biodiesel on NOx Emissions,” Presented to ARB Biodiesel Workgroup, NREL presentation, NREL/PR-540-38296, June 2005.
McCormick, R. L. et al, (2006) “Effects of Biodiesel Blends on Vehicle Emissions,” Milestone Report NREL/MP-540-40554, National Renewable Energy Laboratory, October 2006.
McGill, R., Storey, J., Wagner, R., Irick, D., Aakko, P., Westerholm, M., Nylund, N-O. and Lappi, M. (2003) Emission Performance of Selected Biodiesel Fuels. SAE Technical Paper 2003-01-1866. (Results from IEA-AMF Annex XIII).
McGill, R., Aakko-Saksa, P. and Nylund, N-O. Biomass-Derived Diesel Fuels - Analysis of Biodiesel Options. June 2008.
Mikkonen, S., Hartikka, T., Kuronen, M. and Saikkonen, P. (2011) HVO, hydrotreated vegetable oil – A premium renewable biofuel for diesel engines. Oct 2011 version.
Morris, R. E. et al., (2003) “Impact of Biodiesel Fuels on Air Quality and Human Health – Summary Report,” NREL report NREL/SR-540-33793, National Renewable Energy Laboratory, May 2003.
Murtonen, T. and Aakko-Saksa, P. (2009) Alternative fuels with heavy-duty engines and vehicles – VTT contribution. VTT Working Papers 128.
Murtonen, T., Aakko-Saksa, P., Kuronen, M., Mikkonen, S. & Lehtoranta, K., Emissions with Heavy-duty Diesel Engines and Vehicles using FAME, HVO and GTL Fuels with and without DOC+POC Aftertreatment. SAE International Journal of Fuels and Lubricants, 2010: 2, page 147-166. Also as SAE Technical Paper 2009-01-2693. 20 p.
National Renewable Energy Laboratory (NREL), (2006) “Biodiesel Handling and Use Guidelines - Third Edition” U.S. Department of Energy, DOE/GO 102006-2358, September 2006
Nylund, N-O. and Aakko, P. (2000) Characterization of New Fuel Qualities. Society of Automotive Engineers. Technical Paper 2000-01-2009. Work was conducted within IEA-AMF Annex X (Link to Final report).
Rantanen, L., Linnaila, R., Aakko, P. & Harju, T., NExBTL – Biodiesel fuel of the second generation. SAE Technical Paper 2005-01-3771. 18 p.
Sato, S., Mizushima, N., Saito, A and Takada, Y. (2012) Evaluation of Environmental Impact of Biodiesel Vehicles in Real Traffic Conditions. (Results from IEA Advanced Motor Fuels Annex XXXVIII)
Sharp, C. A., Howell, S. A., Jobe, J. (2000b) The Effect of Biodiesel Fuels on Transient Emissions from Modern Diesel Engines, Part II Unregulated Emissions and Chemical Characterization. SAE Technical Paper 2000-01-1968.
Tsolakis, A. (2006) Effects on Particle Size Distribution from the Diesel Engine Operating on RME- Biodiesel with EGR. Energy & Fuels, 20, 1418-1424.
WWFC (2006) World Wide Fuel Charter. Engine and automanufacturer’s guidebook. 4th Edition.
WWFC (2009) World Wide Fuel Charter. Biodiesel guidelines.