二氧化硅-硫酸氢钾固体酸催化制备生物柴油

采用溶胶-凝胶法制备KHSO4.SiO2固体酸催化剂,将其应用于催化油酸与甲醇制备生物柴油的酯化反应中,考察了催化剂焙烧温度、KHSO4负载量、甲醇与油酸物质的量比、催化剂用量、反应时间及催化剂使用次数对生物柴油转化率的影响。结果表明,固体酸催化剂KHSO4.SiO2在油酸与甲醇的酯化反应中具有很高的催化活性,最佳反应条件:催化剂焙烧温度为200℃,KHSO4负载量为20%,甲醇与油酸物质的量比为12∶1,催化剂用量占油酸质量的10%,反应时间5 h,生物柴油转化率可达95.58%。固体酸催化剂KHSO4.SiO2可重复使用4次,催化活性良好。

Preparation of biodiesel catalyzed by soild acid KHSO4 · SiO2

Biodiesel was produced by the esterification of oleic acid and methanol catalyzed by solid acid KHSO4·SiO2,which was prepared through the sol-gel method.The effects of the catalyst calcination temperature,KHSO4 loading,molar ratio of methanol to oleic acid,catalyst dosage,reaction time and using times of catalyst on the yield of biodiesel were investigated.The results showed that the solid acid catalyst KHSO4·SiO2 in the oleic acid esterification with methanol had a high catalytic activity,and the optimal conditions were as follows:calcination temperature 200 ℃,KHSO4 loading 20%,molar ratio of methanol to oleic acid 12∶ 1,catalyst dosage 10%(based on the mass of oleic acid),reaction time 5 h.Under the optimal conditions,the conversion rate was 95.58%.Solid acid catalyst KHSO4·SiO2 could be used for 4 times with high catalytic activity.