PREPARATION OF BIODIESEL FROM NON-EDIBLE NIGERIAN JATROPHA CURCAS OIL: EFFECTS OF PROCESS PARAMETERS AND KINETICS OF REACTION

Authors : Ude Callistus N, Onukwuli Dominic O, Onwudiro Justina I, Emembolu Lovet N

Pages : 415-437

View : 88 | Download : 12

Publication Date : 2016-09-01

Article Type : Research Paper

Abstract :Transesterification of Jatropha seed oil was carried out on its refined oil extracted by cold method. The physicochemical analysis of the oil and biodiesel produced were carried out using American Oil Chemists Society Methods and the fatty acid composition was done with gas chromatography. The parameters investigated during transesterification were the reaction time, catalysts concentration, methanol/oil molar ratio, and reaction temperature. The high acid value, iodine value and saponification value of the oil enabled it to undergo treatment before transesterification. The major fatty acid in Jatropha curcas seed oil were oleic acid, linoleic acid, palmitic acid and the stearic acid. Transesterification of the refined Jatropha seed oil using homogeneous catalysts reduced the viscosity from 8 to 3.4mm2/s. This achievement paved way to use the produced biofuel as diesel engine fuel without any engine modifications. The heating value of the biodiesel will produce high brake power that can give a reasonable thermal efficiency for a diesel engine. Increase in process parameters increased the yield of methyl ester to a certain point before it decreased and the highest yield obtained is 90%. In the kinetics models studied, rate constant was observed to vary with temperature for both pseudo first and pseudo second order kinetic models considered. The general constant and activation energy for first order and second order kinetics determined were insert ignore into journalissuearticles values(2.31min-1; 12620.65J/mol);, and insert ignore into journalissuearticles values(2.22min-1; 1.435 J/mol);. The coefficient of determination, R2 values were employed to determine the suitable reaction order for the reaction and the highest R2 value of 0.941 was obtained for first order order. The most appropriate reaction order is 1 with respect to JCT. The rate equation for first order kinetic model is –rjCT = 2.31 CjCToexp[-1516/insert ignore into journalissuearticles values(T);]insert ignore into journalissuearticles values(1 – XjCT);. The result shows the potential of producing biodiesel from non edible seed, Jatropha without creating competition in food sector.
Keywords : Biodiesel, jatropha curcas, transesterification, KOH, kinetic model

ORIGINAL ARTICLE URL