Combined phospholipase and lipase catalysis for biodiesel production from phospholipids-containing oil

Free lipase-mediated biodiesel production has been considered to be promising due to its advantages of high catalytic efficiency and lower preparation cost. Exploring the feasibility of free lipase to convert potential low quality oil feedstock into biodiesel is of great significance for further reducing the cost of biodiesel production. However, it is reported that low quality oils usually contain high concentration of phospholipids. Our previous study showed that the presence of high phospholipids content in oil feedstock would lead to poor catalytic performance of free lipase NS81006.Thereby, in order to improve the process, a combined catalysis together with phospholipase Lecitase Ultra and lipase NS81006 was developed in this paper. First, the effect of different factors involved in the process on Lecitase Ultra's catalytic performance was investigated, then a two-step method via phospholipase-catalyzed phospholipids degradation followed by lipase-catalyzed methanolysis was further attempted to promote the conversion of phospholipids-containing oils for biodiesel production. When using oil containing 2,235 ppm initial phosphorus as feedstock, the final biodiesel yield could reach 96.4%, while the yield without phospholipase was only 76.6%. This work demonstrates that the combined catalysis of phospholipase and free lipase has a great prospect in biodiesel production from high phospholipids-containing oil feedstocks.