Optimization of Transesterification of Nigerian Jatropha Curcas oil Using Response Surface Methodology

Abstract

The major challenge associated with the commercial production of biodiesel is the high cost of edible vegetable oil. This necessitates the use of non edible oil such as Jatropha curcas oil for the production of biodiesel. The research presents the report of optimization of alkaline transesterification of Jatropha curcas oil using Response Surface Methodology. A central composite design (CCD) technique consisting of 20 experiments was employed to study the effect of process variables: catalyst concentration (0.25g - 0.75g), methanol to oil ratio (3:1-9:1) and reaction time (60 - 120 min). Statistical analysis of the variables and their interactions were carried out which lead to the development of a regression model. The maximum yield of 98.80 % was obtained at methanol to oil ratio of 6:1, catalyst concentration of 0.75g and reaction time of 90 min. The result of simulation of model equation shows a close agreement with the experimental value. It was deduced that methanol to oil ratio had a higher effect on the biodiesel yield than catalyst concentration and reaction time. Characterization of the biodiesel revealed that it compares favourably with the ASTM standard.