Determination of Optimum Reaction Temperature and Reaction Time for Biodiesel Yield from Coconut (Cocos nucifera) Oil

Abstract

The determination of optimum reaction temperature and time for biodiesel yield from Coconut (Cocos nucifera) oil was studied. The oil was transesterified using potassium hydroxide (KOH) in methanol as catalyst to obtain the crude biodiesel. For the reaction time, the biodiesel production was carried out at 30 min, 45 min, 60 min, 75 min and 90 min while their temperature (60ºC), oil to alcohol ratio (6:1) and catalyst concentration (0.65%) were kept constant. For the reaction temperature, the reaction was carried out at 45ºC, 50ºC, 55ºC, 60ºC and 65ºC, while their reaction time (60 min), oil to alcohol ratio (6:1) and catalyst concentration (0.65%) 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 (ASTM) methods. The results of the study showed that for the reaction time, the optimum yield was obtained at 45 min giving a biodiesel yield (after purification) of 88% while for the reaction temperature, the optimum yield was obtained at 45ºC with a biodiesel yield of 87.4%. General results obtained showed that the optimum yield of biodiesel obtainable from Coconut oil when transesterified using KOH/methanol is about 88%. Overall results indicate that Coconut oil can serve as a veritable feedstock for biodiesel production.