摘要
采用溶胶-凝胶法制备了Al_2O_3-Si O_2复合载体,采用等体积浸渍法在复合载体上负载Zn O制备固体碱催化剂,催化动物脂肪废油酯交换反应来制备生物柴油。研究了Zn O负载量以及复合载体中Al_2O_3/Si O_2质量比对催化剂活性的影响,并通过重复性实验对优化得到的催化剂稳定性进行考察。活性测试表明,当Zn O的负载量为20%,复合载体中Al_2O_3/Si O_2质量比为1∶9时催化剂的活性最佳,酯交换率达到95.2%。另外,对催化剂进行了BET、XRD、CO_2-TPD一系列表征。结果表明,Al_2O_3高度分散渗透于非晶相Si O_2中,形成催化剂的介孔结构。Zn O负载量为20%时催化剂碱性最强,这是导致催化剂高活性的重要原因。
The transesterification of waste animal fat oil to biodiesel with solid base catalyst ZnO/Al2O3-SiO2 was studied. The composite support Al2O3-SiO2 was prepared by sol-gel method and ZnO was loaded on Al2O3-SiO2 by impregnation method. Effects of parameters including the content of ZnO and the Al2O3/SiO2 mass ratio of composite support on catalytic activity were investigated. Reusability experiments were carried out to investigate the stability of the optimal catalyst. The reaction test results showed that the catalyst with loading of20% ZnO on the support and with a Al2O3/SiO2 mass ratio of 1∶ 9 showed the highest transesterification rate of95. 2%. Then the catalysts were characterized by BET,XRD and CO_2-TPD. The results indicated that Al2O3 is utterly dispersed on amorphous SiO2 and mesoporous structure is formed. The catalyst with 20% ZnO content exhibited the strongest basicity,which is closely related to its highest catalytic activity.
出处
《环境工程学报》
CAS
CSCD
北大核心
2015年第12期6097-6102,共6页
Chinese Journal of Environmental Engineering
基金
深圳市环境科研课题
关键词
固体碱催化剂
生物柴油
动物脂肪废油
酯交换
复合载体
solid base catalysts
biodiesel
waste animal fat oil
transesterification
composite supports
