Response surface modelling and optimisation of biodiesel production from Manilkara Zapota L. seed oil

Abstract

Biodiesel production from non-edible oils is one of the prominent research avenues being exploited in recent times to achieve energy and environmental sustainability. The aim of this study is to model and optimise the production of biodiesel from the reaction of ethanol with Sapota (Manilkara Zapota L.) seed oil using potassium hydroxide (KOH) as catalyst. A quadratic response surface model has been developed and validated. Analysis of variance (ANOVA) reveals that the model is significant. The standard deviation is 3.76% and the coefficient of determination (R2) is 0.8438. Numerical optimisation reveal that the optimal biodiesel yield of 89.57% can be achieved at an ethanol to oil molar ratio is 6.58, catalyst amount of 1.07 wt% and temperature of 64.77C. Parametric studies reveal that the yield of biodiesel initially increases with increasing ethanol-oil ratio and catalyst amount but drops off gradually beyond the region of optimality. Temperature has a slight positive effect on the process.