Making Biodiesel from Jatropha Oil: Effect of temperature and KOH concentration on the transesterification reaction based on Base Catalysts

Abstract

transesterification reaction. This study aims to determine the optimum catalyst temperature and KOH concentration on the transesterification reaction of castor oil to produce a product with maximum unsaturated fatty acid content; as well as to study the properties of jatropha oil ester based diesel fuel specifications. Transesterification was performed by reaction of jatropha oil and methanol in ratio of 1: 2 for 2 hours according to variations in temperature and KOH concentration. Temperature variations performed at room temperature, 55°C, and 65°C. KOH variations performed at concentration of 0.2 g, 0.3 g, 0.4 g, 0.5 g, 0.6 g, 0.7 g, 0.8 g and 0.9 g. The research indicated that jatropha oil saponification number was 180.455. Analysis by Gas Chromatography Mass Spectroscopy (GC-MS) were obtained oleic methyl ester (Rt 15.45 min and SI 88), linoleic acid methyl ester (Rt 13.250 min and SI 89), 11-octadecanoic methyl ester (Rt 13.333 min and 94 SI ) and risinoleic methyl ester (Rt 11.383 min and SI 91) as dominant unsaturated fatty acid ester in jatropha oil. Transesterification reaction of jatropha oil in methanol have maximum unsaturated fatty acid content at temperature of 65oC and optimum catalyst concentration of KOH at 0.178 M (0.4 g). Analysis using the American Society for Testing Materials (ASTM) method generated pour point value was 8oF, kinematic viscosity was 16.324 cSt, water content was 0.015 %vol, conradson carbon residue was 0.204 %wt. The properties are very closely to diesel oil specifications that can be used as biodiesel.