Effects of Transesterification Variables on Yields and Properties of Biodiesel Fuels Produced from Four Virgin Tropical Seeds

摘要

Biofuels are gaining more and more importance as alternative fuels due to the depleting fossils fuel resources. In this research work, biodiesel fuels were produced from four different virgin feedstocks namely Telfaria occidentalis, Hura crepitans, Canarium schweinfurthii and Cucumeropsis manii using transesterification method under varying operating conditions of which temperature, catalyst concentration and reaction time were prominent factors affecting the reaction. The production yield of the biodiesels for the various seed oils reveals that KOH is the best catalyst for the transesterification reaction between the triglycerides and alcohol for the production with the highest yield of 98%, 97%, 94% and 92% for Telfaria occidentalis, Cucumeropsis manii, Canarium schweinfurthii and Hura crepitans, respectively. The results also showed that an increase in the ratio of alcohol to oil leads to a corresponding increase in the yield of biodiesel. The optimum ratio of alcohol to oil was found to be 6:1 at which alcohol is usually present in excess and this facilitated the conversion of more of the triglycerides to biodiesel. The optimum temperature, catalyst concentration and reaction time were found to be 55oC, 1% (wt of oil) and 30 min, respectively. The properties such as viscosity, specific gravity and flash points of the various biodiesel fuels produced were investigated and the results showed agreement with ASTM, AOAC, AOCS and IP standards.