(744b) Effect of Phospholipids on Free Lipase-Catalyzed Biodiesel Production

Free lipase-catalyzed biodiesel production has drawn more and more attentions in recent years because of its advantages of lower cost and faster reaction rate. Utilizing free lipase to convert low quality oils such as crude vegetable oils and microbial oils is beneficial to further reduce the cost of biodiesel production. However, these oils typically contain some amount of phospholipids. Phospholipids were found to affect the lipase-catalyzed process and further influence the enzyme’s thermal stability in biodiesel production process. In this work, free lipase-catalyed biodiesel production was systematically investigated with oils containing phospholipids as feedstocks at varied conditions. It was found that increasing temperature led to a decreased fatty acid methyl esters (FAME) yield and poor reuse stability of the lipase in converting oils containing phospholipids for biodiesel production. Further study showed that this inhibitory effect was mainly attributed to the coexistence of phospholipids and methanol in the system. A novel two-step enzyme-catalyzed process was developed, with which the above-mentioned inhibitory effect was eliminated, and a FAME yield of 95.1% could be obtained with oils containing 10% phospholipids as the feedstock.