Glycerol free biodiesel synthesis by application of methyl formate in enzymatic interesterification of rapeseed oil

ABSTRACT The aim of studies was to investigate the process of enzymatic interesterification of rapeseed oil with methyl formate and to determine the influence of three independent variables on the product yield. After evaluating the effectiveness of three enzymatic preparations, the industrial preparation Lipozyme TL IM was selected for the research. Using the surface response methodology, a model describing the dependence of the yield of rapeseed methyl esters on the molar ratio of methyl formate to oil, the amount of catalyst and the duration of the process was created. The following conditions were determined in which the highest yield of rapeseed oil methyl esters was obtained: molar ratio of methyl formate to oil 40:1, process duration 60 h and 14.57% of catalyst Lipozyme TL IM from the amount of oil. Under these conditions, an 81.79% yield of rapeseed oil methyl esters was obtained. Comparative studies of the physical and chemical properties of the product obtained during the interesterification process were performed and their compliance with the requirements of conventional biodiesel standard EN 14214 was evaluated. GRAPHICAL ABSTRACT