Blending Study of Palm Oil Methyl Esters with Rubber Seed Oil Methyl Esters to Improve Biodiesel Blending Properties

Abstract

Palm oil methyl esters (POME’s) significantly contributed towards biodiesel production commercially. Rubber seed oil methyl esters (RSOME’s) with non-edible properties and significant amount of unsaturated fatty acid content contributed to enhancement of low temperature properties along with remedy on food scarcity dilemma. Post blending of POME’s and RSOME’s at different volumetric ratios improved the low temperature properties of fuel. POME’s resulted in excellent oxidation stability with induction period (IP) of 25.52 h compared to RSOME’s which only exhibited IP of 3 h. Contrarily, RSOME’s showed positive behavior towards low temperature properties. GC analysis determined the significant improvement in low temperature properties as the saturated methyl esters composition is reduced in post blended mixture. The optimized blend value where both low temperature properties and oxidation stability were determined at acceptable limits was found at blend ratio of POME’s to RSOME’s at 20:80. All the blends satisfied the international biodiesel criteria of EN and ASTM. Transesterification kinetics of POME and RSOME were investigated and followed pseudo-first order kinetics. Activation energy for POME was found to be 33.2 kJ/mole and for RSOME was found to be 43.4 kJ/mole. Frequency factor for POME andRSOME was found to be 2.4 x 10³ min^-1 and 1.3 x 10³ min^-1 respectively.