Current Biodiesel Production Technologies: A Comparative Review

Despite the high energy demand in the industrialized world and the pollution problems caused by widespread use of fossil fuels, the need for developing renewable energy sources with less environmental impact is increasing. Biodiesel production is undergoing rapid technological reforms in industries and academia. The major obstacle in producing biodiesel commercialization path is production cost. Thus, in previous years numerous studies on the use of technologies and different methods to evaluate optimal conditions of biodiesel production technically and economically have been carried out. In this study, a comparative review of the current technological methods so far used to produce biodiesel has been investigated. Different studies were carried out using different oils as raw material, different alcohol (methanol, ethanol, buthanol) as well as different catalysts, homogeneous ones such as sodium hydroxide, potassium hydroxide, and sulfuric acid, and heterogeneous ones such as lipases. Beside catalytic methods, non-catalytic methods for biodiesel production in which instead of using catalysts, high pressure and temperature are used to carry out the transesterification, reaction were also investigated. Generally, in this review advantages and disadvantages of different methods have been studied too.