Synthesis of glycerol free-fatty acid methyl esters from Jatropha oil over Ca-La mixed-oxide catalyst

Synthesis of glycerol free-methyl esters (FAME) has been studied for the transesterification of non-edible Jatropha oil using dimethyl carbonate (DMC) as methylating agent over heterogeneous Ca-La mixed-oxide catalyst. The various effects of reaction conditions, such as DMC-to-oil molar ratio (2:1-15:1), reaction temperature (120-160 degrees C), reaction time (30-240 min), and amount of catalyst loading (1-10 wt.%) were investigated. Catalyst reusability and regeneration were also studied. Results showed that a 4:1 molar ratio of DMC to oil, 150 degrees C reaction temperature, 120 min reaction time, and 3 wt.% of catalyst loading showed the best value, with conversion and yield of 99.84%. Reusability test resulted in a stable FAME yield above 96.5 wt.% after being used for 4 reaction cycles and then slightly dropping to 94.24% after the fifth cycle of reaction, whereas for regeneration test, conversion and yield remained constantly at >99% after five times of catalyst regeneration. This finding showed that DMC was a good methylating agent for methanol substitution, and that Ca-La mixed-oxide was an active, stable, and effective catalyst for the transesterification of Jatropha oil. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.