Transesterification of Soybean Oil to Biodiesel in a Microwave-Assisted Heterogeneous Catalytic System

A novel heterogeneous base catalyst for biodiesel production was prepared from the support of alumina/silica loaded with potassium sodium tartrate by a one-step sol-gel process and the optimal conditions were investigated. Microwave-assisted transesterification of soybean oil was carried out for the production of biodiesel. The catalysts were characterized by FT-IR, TG-DSC, SEM, TEM, EDX, XRD, and the Hammett indicator. The effects of the molar ratio of methanol to oil, reaction temperature, and amount of catalyst on the biodiesel yield were determined. The prepared heterogeneous catalyst could be easily separated from the reaction system with high efficiency and its constant activity maintained after application for four cycles.