Esterification of Oleic acid in biodiesel synthesis with SO 42-/ZrO2/MCM-41 as catalyst

Abstract

SO42-/ZrO2/MCM-41 was prepared by impregnation method with self-synthesized MCM-41. The investigation of effects on ZrO2 load ratio and sulphur acid concentration sifted that the catalyst with 40 % ZrO2 load ratio, 1.5 mol/L sulphur acid performed best. Oleic acid was chosen as a simulation of high-acid-value oil to esterify with methanol. The experimental results showed that SO42-/ZrO2/MCM-41 was a high active catalyst in esterification. The optimal condition was as following: the reaction temperature was 80 °C, the oleic acid/methanol molar ratio was 4:1, the catalyst amount was 5 % (wt./wt.) of the oleic acid and reaction time was 4 h. Under this condition, the oleic acid conversion could reach 82.6 %. Characterization results of XRD, TEM and SEM showed that SO42-/ZrO 2/MCM-41 had the typical structure of MCM-41 and SO42-/ZrO2. Reusability tests indicated that the load progress largely improved the water tolerance of SO42-/ZrO2 and reduced the sulphur leaching rate of it. © 2013 Asian Journal of Chemistry.