Thermal Behaviors of Soy Biodiesel

摘要

Soy biodiesel derived from soybean oil was produced through the tranesterification method, using a homogeneous catalyst. The constituents of the biodiesel were determined by gas chromatography (GC). Thermal behaviors were characterized using thermogravetric analyzer (TGA), differential scanning calorimetry (DSC), pressurized differential scanning calorimetry (PDSC), and sorption analyzer (SA). GC results show that methyl esters content was 99% when the unsaturated fatty acid methyl esters accounted for 81%. TGA results illustrate that all the triglycerides had been converted to methyl esters and the total weight loss was 99%. The onset decomposition temperature of the biodiesel was 193 °C. PDSC results show that the oxidation onset temperature (OOT) of the soy biodiesel was 152 °C and the oxidative induction time (OIT) was 24 mins, a little higher than that of commercial biodiesel. DSC results demonstrate that the onset crystallization temperature of the biodiesel was 1.0 °C. The SA results point out that the water adsorption-desorption was a reversible process. Preferable storage conditions for the biodiesel occur when the humidity is less than 30%.