Kinetics of transesterification of palm-based methyl esters with trimethylolpropane

Kinetics of transesterification of palm-based methyl esters (POME) with trimethylol propane (TMP) to polyol esters was investigated. A kinetic model of reaction was obtained by assuming a series of irreversible elementary reactions at various temperatures. The reaction rate constants were determined under limited conditions. The optimal ratios for k(2)/k(1) and k(3)/k(1) were 0.70-0.80 and 0.21-0.25, respectively. Bot palm oil methyl esters (PPOME) and palm-kernel oil methyl esters (PKOME) were reacted with TMP by using sodium methoxide as catalyst. The POME-to-TMP molar ratio and catalyst weight percentage were held constant at 10:1 and 0.4%, respectively. The effects of temperature (70-110degreesC) and raw materials (PKOME and PPOME) were investigated and found to have a significant impact on the reaction kinetics. When using a large excess of POME and continual withdrawal of methanol via vacuum, the reaction reached completion in less than 20 min at 80degreesC. After removal of unreacted POME, the final product contained approximately 98 wt% triesters.