Transesterification of vegetable oil with methanol in the presence of catalyst is a vital industrialized process and it has been well established. In general, there are three categories of catalysts used to catalyze transesterification reaction for biodiesel pro­duction: alkalis, acids, and enzymes (Ma and Hanna 1999). The alkali and acid cata­lysts including homogeneous and heterogeneous catalysts are commonly used in biodiesel synthesis process. The comparison between homogeneous, heterogeneous, and enzymatic catalyzed transesterification reaction was shown in Table 10.2.