Solid catalysts are easily separated from biodiesel product, and therefore using solid catalysts can greatly simplify the process of biodiesel production. Zn/Al hydrotalcite was prepared and it was served as the precursor of Zn/Al compound metal oxide catalyst. Calcining Zn/Al hydrotalcite at 400 ℃ for 10 h obtained the catalyst, which achieved a oil conversion as high as 89.1 % within 3 minutes under the conditions of 200 ℃, 3.3 MPa, 70 g refined rapeseed oil, 100 g methanol, and 1.4 (wt) % catalyst dosage. Furthermore, XRD, TG/DTA, XPS, AAS and BET measurements were used in the characterization of the catalysts. The results show that a high specific surface area and an optimal pore structure are necessary in order to obtain a high dispersion of active component as well as a high activity.
