ARS | Publication request: Improving the cold flow properties of biodiesel with synthetic branched diester additives

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: November 22, 2011
Publication Date: April 29, 2012
Citation: Moser, B.R. 2012. Improving the cold flow properties of biodiesel with synthetic branched diester additives [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 1.

Technical Abstract: A technical disadvantage of biodiesel relative to petroleum diesel fuel is inferior cold flow properties. One of many methodologies to address this deficiency is employment of cold flow improver (CFI) additives. Generally composed of low-molecular weight copolymers, CFIs originally developed for petrodiesel are generally not as effective when added to biodiesel. Consequently, synthetic diesters with multiple branching points were prepared and evaluated as potential CFIs in soybean-based and used cooking oil-based biodiesel fuels. Produced by acid-catalyzed condensation of 5-6 carbon diacids with 5-6 carbon branched alcohols (or vice versa), the diesters have molecular weights similar to biodiesel and are miscible in any proportion with biodiesel. Of the eight diesters prepared, those exhibiting the lowest melting points (< -80 deg C) were explored further as potential CFIs. Selected diesters were also evaluated for efficacy as anti-wear additives in petrodiesel. Overall, the diesters improved the cold flow properties of biodiesel and were effective as lubricity additives in petrodiesel.