KF/CaO催化剂催化大豆油酯交换反应制备生物柴油

Preparation of Biodiesel from Soybean Oil by Transesterification on KF/CaO Catalyst

采用等体积浸渍法制备了KF/CaO催化剂,并将其用于催化大豆油与甲醇酯交换反应制备生物柴油。考察了催化剂制备条件和反应条件对酯交换反应的影响。实验结果表明,通过等体积浸渍并在873K煅烧4h,可以制得理想的KF添加量(KF与CaO的质量比)为14.3%的KF/CaO催化剂,采用该催化剂,当醇与油摩尔比为12∶1、催化剂用量(催化剂与油的质量比)为3%、反应温度为60～65℃、反应时间为1h时,生物柴油的收率可以达到90%。与CaO催化的酯交换反应结果相比,KF/CaO催化剂的催化活性明显提高。XRD与TG-DTG分析结果表明,KF/CaO催化剂酯交换活性的增强与KF与CaO经过高温煅烧发生相互作用而形成新的晶相密切相关。

Transesterification of soybean oil and methanol on KF/CaO catalyst to prepare biodiesel was studied. The catalyst was prepared by isochoric impregnation and had strong basicity. Effects of catalyst preparation conditions and reaction conditions on transesterification were investigated. Optimal catalyst preparation conditions were: mass ratio of KF to CaO, 0.143; calcination temperature, 873 K; and calcination time, 4 h. Optimal transesterification conditions were n(methanol) : n(oil) = 12 :1, m(catalyst) : m(oil) = 0.03, reaction temperature 60-65°C and reaction time 1 h, yield of biodiesel could reach about 90% which was obviously better than single component CaO catalyst. The analyze of XRD and TG-DTG showed that improvement of catalyst activity was closely related to formation of new crystal phase due to interaction of KF and CaO during calcination.