Reduction of the Cloud Point of Biodiesel by Combination of Various Factors

Abstract

Abstract-Optimization to reduce the cloud point of biodiesel fuel (BDF) was investigated by considering the combination of different kinds of alcohols for transesterification, catalyst type, and blending with castor BDF. Rapeseed oil (R), spent coffee oil (S), and jatropha oil (J) were used as raw materials. The cloud point of BDFs prepared with 1-butanol was found to be lower than that of those using methanol. H 2 SO 4 was a more effective catalyst to reduce cloud point than NaOH. As for blending with castor BDF, the cloud point was decreased from −7 to −7.5 °C for a 25 wt% blend of castor BDF with R-BDF, from 10.2 to 8.0 °C with S-BDF, and from 8.2 to 2.8 °C with J-BDF with permissible increases of kinetic viscosities. From the above results, the optimized conditions of 1-butanol, H 2 SO 4 and 25 wt% castor BDF were determined. Under these conditions, the cloud points were −7.5, 2.8 and −3.5 °C for R., S. and J. BDFs, respectively. This paper that the blend ratio of castor BDF was at 25 wt% or less, it was possible to suppress the increase in kinetic viscosity.