Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/13/1998
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Esters from transesterification of soybean oil with methanol (biodiesel) are attractive as alternative fuels and extenders for combustion in direct-injection compression ignition (diesel) engines. During extended periods of storage, oxidation degradation of methyl soyate may occur more rapidly than petroleum middle distillates under analogous conditions. This work is an investigation of the effects of oxidation under accelerated conditions on fuel properties of methyl soyate. With respect to reaction time, these studies showed that kinematic viscosity, acid value and peroxide value depended greatly upon temperature of oxidation. Specific gravity increased slightly with increasing temperature while cloud point and pour point were not significantly affected as temperature increased to 150C. Pressurized-differential scanning calorimetry (PDSC) and conductivity-based analytical techniques were developed and tested for methyl soyate samples from four different sources. In general, induction period did not depend greatly on the source of methyl soyate. Finally, addition of an antioxidant (tert.-butylhydroquinone) was shown to increase induction period and improve resistance of methyl soyate to oxidation.