PROCESS OPTIMIZATION OF BIODIESEL PRODUCTION FROM CRUDE COCONUT SEEDS OIL USING CAO/AL2O3 AS HETEROGENEOUS CATALYST

Abstract

Biodiesel is an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animal fats. Biodiesel is a promising alternative fuel derived from animal fats or vegetable oil through transesterification with methanol. Base catalyzed transesterification is the most commonly used technique as it is the most economical process. Presently, a lot of heterogeneous catalysts have been formulated that are more effective than the homogeneous catalysts. CaO/Al2O3 was synthesized using incipient wetness impregnation method. The biodiesel was developed and optimized using Box-behnken response surface methodology (RSM) design provided using MINITAP-17 statistical software. The four independent variables considered are: reaction time, methanol to oil ratio, reaction temperature and catalyst concentration. The response chosen was fatty acid methyl ester (FAME) yields which were obtained from the reaction. The result from analysis of variance (ANOVA) showed a satisfactory result. Moreover, the input variables showed greater significance on the response which are reaction time and temperature base on F and P-value. The statistical models developed for predicting biodiesel yield revealed a significant agreement between the experimental and predicted values (R = 0.9686). An optimum methyl ester yield of 93.29 % was achieved with optimal conditions of methanol/oil molar ratio of 6:1, temperature of 600C, reaction time of 120 min and catalyst concentration of 1.0 wt%. The properties of the biodiesel produced also falls within the range prescribed by ASTM standard