Enzyme-Catalyzed Transesterification for Biodiesel Production

This chapter reviews enzyme-catalyzed biodiesel production, focusing on lipase as biocatalysts, factors affecting lipase-catalyzed transesterification, advancements in immobilization techniques, and development of bioreactors for competent transesterification with economic considerations for developed technology. To obtain high biodiesel yield, the transesterification process and rate of reaction can be affected by different parameters, such as chain length of alcohol, alcohol to substrate molar ratio, use of solvents, reaction temperature, water content, and catalyst concentration. For commercialization of enzyme-based biodiesel production, the enzymatic transesterification reaction should be performed at the reactor level. The most commonly used reactors for enzyme-based biodiesel production are stirred tank reactors, packed-bed reactors, and fluidized-bed reactors. Economic evaluation of any process technology is a key driving force for successful implementation at the commercial level. The major cost factor for industrial biodiesel production is the cost of feedstock, which adds up to 70% to 95% of the total production cost.