Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/19/2009
Publication Date: 11/15/2009
Citation: Dunn, R.O. 2009. Thermodynamic Study on the Effects of Minor Constituents on Cold Weather Performance of Biodiesel [abstract]. International Biodiesel Congress. p. 33.
Technical Abstract: Biodiesel is an alternative diesel fuel made from vegetable oils, animal fats and other lipid feedstocks. Fuel properties and performance of biodiesel during cold weather are influenced by factors related to its feedstock, namely fatty acid composition and trace concentrations of monoacylglycerols, steryl glucosides and other minor constituents may be present after conversion. This study applies thermodynamic models to determine the effects of small variations in fatty acid methyl ester (FAME) concentration and very small concentrations of minor constituents on crystallization onset temperature and cloud point (CP). Differential scanning calorimetry (DSC) curves are analyzed to determine melting point (MP) and enthalpy of fusion of various FAME components, monostearin, monopalmitin, beta-sitorsteryl glucoside, free fatty acids, sodium and potassium salts of fatty acids (soaps), alpha-tocopherol, glycerol and water. Data calculated from thermodynamic models are compared with direct experimental measurement of CP of corresponding mixtures of FAME and constituents. Effects of interactions between types of minor constituents are also evaluated.