Determination of Optimum Catalyst Concentration for Biodiesel Yield from Coconut (Cocos nucifera) Oil

Abstract

The determination of optimum catalyst concentration for biodiesel yield from Coconut (Cocos nucifera) oil was studied. The oil was transesterified using potassium methoxide as catalyst to obtain the crude biodiesel. The reaction was carried out at different catalyst concentrations of 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1% and 1.2% w/v KOH, while the speed of stirring, reaction time (60 min), alcohol to oil ratio (6:1) and reaction temperature (60oC) were kept constant. The crude biodiesel were purified by washing with water severally to obtain the relatively pure biodiesel. They were dried using solar dryer for a period of four (4) days to obtain moisture-free pure biodiesel. They were subsequently analyzed for various parameters; Kinematic viscosity, acid value, free fatty acid (FFA), specific gravity, iodine value, ash value and flash point. The different variants gave results of the parameters analyzed comparable to International standards of biodiesel. The results of the study showed that, the optimum yield was obtained at 0.7% w/v catalyst concentration giving a biodiesel yield of 87.2%. At the catalyst concentrations of 1.1% and 1.2%, no biodiesel yield were obtained, instead there was formation of emulsion. General results obtained show that the optimum yields of biodiesel obtainable from Coconut oil when transesterified using KOH/methanol at the catalyst concentration of 0.7% w/v KOH is about 87%. Overall results indicate that Coconut oil can serve as a veritable feedstock for biodiesel production.