Transesterification of Soybean Oil to Biodiesel Catalyzed by Ionic Liquid

[Objective]The ionic liquid(1-methylic-3-butyl imidazolium hydrogen sulfate) was prepared and the transesterification of soybean oil to biodiesel catalyzed by the ionic liquid was studied.[Method]The effects of molar ratio of methanol to oil,reaction time,reaction temperature and ionic liquid dosage on the transesterification reaction and stability of the ionic liquid were investigated.[Result]The optimum reaction conditions were obtained as follows:molar ratio of methanol to oil of 14∶1,reaction time of 12 h,reaction temperature of 100 ℃,dosage of ionic liquid of 8% of the oil weight.The conversion rate of biodiesel reached 90% under the optimum reaction conditions.[Conclusion]The ionic liquid was stable and it could be used repeatedly.