【摘要】 研究了微波辐射下,采用KNO3/Al2O3固体碱催化剂,大豆油和甲醇酯交换反应制备生物柴油的工艺。催化剂的最佳制备条件为:KNO3的负载量(质量分数)35%,700℃下焙烧5h。采用傅里叶变换红外光谱、X射线衍射和Hammett滴定对催化剂进行了表征。表征结果显示,KNO3在Al2O3表面分散形成的Al—O—K物种和KNO3高温分解产物K2O为反应提供了活性位。该反应的优化工艺参数:微波输出功率360W,反应时间35min,催化剂质量分数6.0%,甲醇与大豆油的摩尔比13。在该条件下,大豆油的转化率达到97.5%。与水浴加热方式相比,采用微波辐射加热方式,反应时间明显缩短,能耗减少。更多还原

【Abstract】 Transesterification of soybean oil with methanol over KNO₃/Al₂O₃ solid base catalyst under microwave radiation was carried out to prepare biodiesel oil.Under the optimal preparation conditions:KNO₃ mass fraction on Al₂O₃ 35%,calcination temperature 700 ℃,time 5 h,the catalyst is the best in activity.The catalysts were characterized by means of FTIR,XRD and Hammett titration method.The Al—O—K formed on surface of Al₂O₃ by KNO₃ dispersion,together with K₂O decomposed from KNO₃ at high temperature,which provided active basic sites for the reaction.Under the optimal reaction conditions:microwave power 360 W,reaction time 35 min,catalyst mass fraction 6.0% and mole ratio of methanol to soybean oil 13,conversion of soybean oil can reach 97.5 %.Comparing with conventional heating methods,the catalytic process on solid base catalyst aided by microwave irradiation is proved to be faster in reaction rate with lower energy consumption.更多还原