Assessment of KOH and NaOH Catalysed Biodiesel from Melon Seed Oil

Abstract

In this study, the comparative analysis of KOH and NaOH catalysts (used separately and combined in equal proportion) during the trans-esterification of melon seed oil was investigated. The major effects and interactions of four variables (methanol/oil mole ratio, catalyst concentration, reaction temperature and reaction time) on the yield of biodiesel were studied. The results showed that, under the same experimental conditions, KOH catalyzed trans-esterification produced the highest biodiesel yield, followed by NaOH catalyzed process and then trans-esterification process involving a mixture of the two catalysts (in equal proportion). KOH catalysed process gave optimum conditions of 6.11 methanol/oil mole ratio, KOH concentration of 1.20 w/w% Oil, reaction temperature of 50 _C, reaction time of 83 minutes and optimum yield of 80.7%. NaOH catalysed process gave optimum conditions of 6.20 methanol/oil mole ratio, NaOH concentration of 1.19 w/w% Oil, reaction temperature of 52 _C, reaction time of 83 minutes and optimum yield of 77.9%. While the process involving the mixture of the two catalysts gave optimum conditions of 6.08 methanol/oil mole ratio, catalyst concentration of 1.05 w/w% Oil, reaction temperature of 56 _C, reaction time of 85 minutes and optimum yield of 76.2%. Material balance carried out on the three categories of analysis favoured KOH trans-esterification process and the suitability of the biodiesel yield models obtained in these three categories was justified by high R2 values of 0.9489, 0.9631 and 0.9605 respectively.