Heavea brasiliensis (Rubber seed): An alternative source of renewable energy

Abstract

This research work studied the suitability of using Cocoa Pod Husk (CPH) as a base catalyst for transesterification of Heavea brasiliensis oil (HBO) to Heavea brasiliensis methyl ester (HBME) via three-step modeling and optimization technique using response surface methodology (RSM) and artificial neural network (ANN). The first step modeled and optimized the extraction of oil from Heavea brasiliensis seed using soxhlet extractor. The esterified conversion of high free fatty acid HBO was carried out in the second step while the third step involved the optimization of the transesterification of the esterified Heavea brasiliensis oil (HBOE) to HBME using CPH.Results showed the maximum HBO yield of 43.50% (w/w), at the following conditions; sample weight of 50 g, solvent volume of 250 ml and extraction time of 40 min (Run 11). The predicted values were validated in triplicate in order to determine the optimum yield, and an average content of 37.85% (w/w) and 39.65% (w/w) were obtained for RSM and ANN, respectively. Acid catalyst esterification step showed the predicted values were validated in triplicate in order to determine the minimum acid value, and mean values of 1.76 (RSM) and 1.86 (ANN). The catalytic activity of CPH employed for biodiesel production produced 97% (w/w). The predicted optimum yield was validated in triplicate, and the mean yields of 94.06% (w/w) and 96.65% (w/w) were obtained for both RSM and ANN, respectively. The produced HBME in this study is within the limit of methyl ester standard specifications prescribed by ASTM D6751 and EN 14,214.