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United States Department of Agriculture

Agricultural Research Service

Title: Improving the Low-Temperature Operability of Biodiesel

Author
item Dunn, Robert

Submitted to: Biomass for Energy and Industry European Conference and Technology Exhibit
Publication Type: Abstract Only
Publication Acceptance Date: June 11, 1998
Publication Date: N/A

Technical Abstract: Biodiesel, defined as the mono-alkyl fatty acid esters obtained from transesterification of veg oil or animal fat, is attractive as an alternative diesel fuel. Biodiesel provides comparable engine performance and reduces smoke, hydrocarbon and polycyclic aromatic hydrocarbon exhaust emissions. However, biodiesel has relatively poor low-temperature flow properties with respect to petroleum middle distillates. When overnight temperatures decrease below 0C, wax crystals form in methyl soyate that can plug fuel lines and filters, causing start-up and operability problems. The analogous limit for distillates is -10 to -15C. This work evaluates several approaches for improving low temp flow properties of biodiesel. Treatment with cold flow improvers reduced the pour point of biodiesel and biodiesel distillate blends. However, these additives did not greatly affect CP; consequently, they did not greatly improve cold flow prop of biodiesel or blends. Winterization and cold solvent extraction were effective at reducing CP because these approaches attacked the problem by increasing the total concentration of lower melting unsaturated long-chain fatty esters. Although these techniques decreased storage stability with respect to autoxidation, they did not compromise fuel quality of methyl soyate with respect to standard fuel specs for biodiesel.

Last Modified: 4/17/2014
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