A novel and highly efficient process for the production of biodiesel from high-acid content waste cooking oil (WCO) was developed. Free fatty acids (FFAs) and partial glycerides in WCO were first converted to FA methyl esters (FAME) by immobilized partial glycerides selective lipase SMG1-F278N-catalyzed esterification/transesterification, while leaving triacylglycerol (TAG) intact. FFAs decreased from 28.69% to 0.05% after 8h of reaction under the applied optimal conditions and the immobilized SMG1-F278N showed excellent reusability up to 20 consecutive batches. Subsequently, the remaining TAG was transesterified to FAME by sodium hydroxide-catalyzed transesterification and 98.24% FAME was obtained after 20min of reaction.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.