锌改性 Ca-Mg／Al 类水滑石催化制备生物柴油

摘要

By doped with different proportion of Zn(NO3 )2 into Ca-Mg/Al hydrotalcite catalyst,the modified catalysts were used for biodiesel synthesis,taking transesterification of microalgae oil with methanol as probe reaction and biodiesel yield as activity evaluation index,and studying the effect of different amount of Zn(NO3 )2 on the catalytic activity.Furthermore,TG/DSC,XRD,BET and SEM measurements were used in the characterization of the catalysts and its precursor.The results showed that the optimum conditions are as follows:using addition of Zn(NO3 )2 modified Ca-Mg/Al hydrotal-cite as catalyst,when n(Zn)∶n(Zn+Mg)=12%,reaction temperature 65 ℃,methanol to microalgae oil molar ratio of 14∶1,reaction time of 4 h and 3% of catalyst,diesel yield can reach 94%.%通过掺杂不同比例的 Zn（NO3）2实现对 Ca-Mg／Al 类水滑石催化剂的改性，将改性后催化剂用于制备生物柴油，并以微藻油和甲醇酯交换反应为探针反应，生物柴油收率为催化剂活性评价指标，研究不同 Zn（NO3）2的加入量对其催化活性的影响。通过 TG-DSC、XRD、BET、SEM 等手段对催化剂及其前体进行了表征。结果表明，当 n（Zn）∶n（Zn＋Mg）＝12％时，改性后的 Ca-Mg／Al 类水滑石催化剂在反应温度为65℃，n（甲醇）∶n（微藻油）＝14∶1，反应时间为4 h，m（催化剂）∶m（微藻油）＝3％，生物柴油收率可达到94％。