Deacidification of high-acid rice bran oil by esterification for the raw material of biodiesel

To take full advantage of the high-acid rice bran crude oil, the authors carried out experiments to deacidify high-acid rice bran crude oil by esterification for the raw material of biodiesel. In this paper, the esterifying catalytic activity of several catalysts and the influence of glycerol dosage, catalyst dosage, reaction temperature and reaction time on deacidification were investigated. The results showed that ZnO had a strong catalytic activity. The optimum conditions of esterification with ZnO were the theoretical amount of glycerol dosage(1.044 g), the 0.1% (m/m) ZnO dosage, the reaction temperature 200℃ and the reaction time 6 h. The acid value of the rice bran oil after esterification drops from 38.14 mg/g to 5.17 mg/g under above optimum conditions. This low-acid rice bran oil is suitable as the raw material of biodiesel.