Optimized microemulsion production of biodiesel over lipase-catalyzed transesterification of soybean oil by response surface methodology

Abstract

Production of biodiesel in water/oil (w/o) microemulsion system through a lipase-catalyzed (lipase from porcine pancreas) methanolysis of soybean oil was investigated. The independent factors were researched and response surface methodology (RSM) based on the Box-Behnken design was used to optimize the significant reaction variables, including w0 (defined as the molar ratio of water to surfactant), lipase concentration, reaction time and substrate molar ratio. Results indicated that the optimal conditions for biodiesel preparation were: w0 3.6, lipase concentration 4.3% (based on oil weight, g), reaction time 17 h and molar ratio (methanol/oil) 10.5. The actual fatty acid methyl ester yield (96.8%) coincided with the optimum predicted value (97.5%) under the optimal conditions. Fatty acid methyl ester synthesized in microemulsions directly which may provided a potential way to produce biodiesel microemulsion.

Keywords

• biodiesel
• lipase catalyzed transesterification
• microemulsion
• optimization by rsm