Author
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Knothe, Gerhard |
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Dunn, Robert |
Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only Publication Acceptance Date: 5/12/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Biodiesel is defined as the mono-alkyl esters of a vegetable oil or animal fat. One of the problems associated with the use of biodiesel as alternative diesel fuel is its relatively poor low-temperature properties. Several potential solutions such as cold flow-improving additives, winterization, use of branched esters, and blending with conventional diesel fuel exist or have been investigated for decreasing cloud and pour points of biodiesel. As additives, usually various polymers (often ethyl vinyl acetate copolymers) have been studied and used. Previous work on crystallization of fatty compounds and some of the approaches mentioned above suggest that other types of additives for improving the cold flow properties of biodiesel and its blends may also be effective. These compounds would have bulky or branched structures. Different classes of compounds were synthesized and studied in the course of this work including branched esters, Guerbet-based branched compounds, and previously prepared compounds with bulky substituents in the chain. The limited effect of these compounds on the low-temperature properties suggests that crystallization behavior of fatty compounds in the presence of cold-flow improvers depends on the chain length of additives with greater chain lengths being preferable or the use of compounds such as branched esters neat or in high, additive-level- exceeding concentrations. Some of the compounds were investigated for their analytical characterization, especially mass spectrometry. |