Energy & Fuels, Vol.31, No.6, 6206-6210, 2017
Steam Deacidification of High Free Fatty Acid in Jatropha Oil for Biodiesel Production
Although non-edible oil feedstocks are available at a lower price than edible oil feedstocks, their high free fatty acid (FFA) content hinders their direct utilization in the production of biodiesel by alkali-catalyzed transesterification. In this study, the steam deacidification process, has been employed in reducing the FFA of crude Jatropha oil before alkali-catalyzed transesterification. The response surface methodology (RSM) established on the central composite design (CCD) was used to model and optimize the steam deacidification efficiency under two process variables, namely, temperature and amount of steam. The optimum conditions for deacidification efficiency of 98.74% were found to be the temperature of 235 degrees C and the amount of steam of 3.4% (w/w) of the feedstock. These conditions reduce the high FFA of crude Jatropha oil from 4.54 to 0.09%, which is below 1% recommended for base-catalyzed transesterification. The deacidified crude Jatropha oil was then transesterified using a homogeneous base catalyst and gave a conversion of 97.45%. The tested fuel properties of biodiesel, such as viscosity at 40 degrees C, acid value, gross calorific value, iodine value, fatty acid methyl ester (FAME) content, and density at 15 degrees C, were found to be comparable to those of ASTM D6751 and EN 14214 standards.