Batch production of FAEE-biodiesel using a liquid lipase formulation

The application of lipase catalysis to the production of biodiesel has received much interest during the past several years. Although most of the previous work has involved the use of immobilized enzyme, more recent work has indicated that liquid formulations of lipase can provide a highly competitive option for the conversion of oils and fats to biodiesel. This study investigates the impact of several process parameters on the production of fatty acid ethyl esters from rapeseed oil in a pure batch process on the liquid lipase formulation Callera™ Trans L. Oil conversion in excess of 98% was achieved by combining a 50% stoichiometric excess of ethanol (1.5 equivalents) with 20% (w/w) water relative to the oil. The rate of reaction was directly proportional to the amount of lipase added in this system (500–2000 LU per gram oil). Addition of glycerol to the initial reaction mixture reduced the initial reaction rate, but also improved the final yield of biodiesel by suppressing hydrolysis.