Enzymatic biodiesel production from crude Eruca sativa oil using Candida rugosa lipase in a solvent-free system using response surface methodology

Abstract

ABSTRACTIn the present study, enzymatic biodiesel production from low-cost, non-edible crude Eruca sativa oil was investigated. Candida rugosa lipase (CRL), a commercially promising biocatalyst in different industries, was used. Although this source of lipase has been reported as unsuitable for biodiesel production from non-edible oil, in this study, it was attempted to use this enzyme for production of fatty acid methyl esters (FAME) from Eruca sativa oil in a solvent-free system. For the first time, the effects of pre-hydrolysis and pH on the yield of biodiesel were evaluated. Afterward, the four most commonly reported influential parameters were analyzed with the use of response surface methodology (RSM). It was observed that pre-hydrolysis had a significant effect on biodiesel conversion due to the mechanism of enzymatic biodiesel production. Deionized water was more efficient in comparison with phosphate buffer with different pH values. According to the RSM analysis, water content and temperature have a highly significant effect on biodiesel production. Methanol-to-oil ratio and enzyme amounts were also significant factors in FAME production. The optimum methanol-to-oil ratio, enzyme amount, water content, and temperature for achieving high conversion was found to be 3:1, 5 mg, 40%, and 21 °C, respectively.