固体碱催化剂K_2CO_3/Al_2O_3的制备及其催化餐饮废油制生物柴油的性能

采用浸渍法制备了K2CO3/Al2O3固体碱催化剂,考察了活性组分负载量、焙烧温度、焙烧时间等制备条件对催化剂在催化餐饮废油合成生物柴油的酯交换反应中催化活性的影响,并对其进行了FT-IR、XRD、TG-DTG、SEM和BET表征分析。实验结果表明,所制备的催化剂在催化餐饮废油合成生物柴油的酯交换反应中表现出良好的活性,在活性组分K2CO3负载量为50%、焙烧温度500℃、焙烧时间3 h的条件下制备的催化剂催化酯交换反应时,生物柴油产率可达86.70%。催化剂表征结果显示,K2CO3/Al2O3催化活性是因K2CO3与Al2O3经高温焙烧产生新的晶相有关。催化剂重复使用4次,生物柴油产率仍在75%以上。制得的生物柴油产品质量达到国家生物柴油B100标准。

Preparation of solid base K2CO3/Al2O3 and catalytic conversion of waste cooking oil to biodiesel

The solid base catalyst K₂CO₃/Al₂O₃ was prepared by impregnation method. The factors to influence the reaction activity of producing biodiesel from waste cooking oil including the loading of active component K₂CO₃ on the catalyst, the roasting temperature and the roasting time were investigated. The catalysts were characterized by FT-IR, XRD, TG-DTG, SEM and BET techniques. The results show that the catalyst exhibits an excellent catalytic activity for the transesterification of waste cooking oil to biodiesel. The solid base catalyst loaded with 50% K₂CO₃ and calcinated at 500 ℃ for 3 h exhibits a high catalytic activity for the transesterification, and the yield of biodiesel reaches 86.70%. The characterization reveals that the catalyst activity of K₂CO₃/Al₂O₃ is associated with the formation of new crystalline phase due to the interaction between K₂CO₃ and Al₂O₃ during calcination. After the catalyst is reused for 4 times, the yield of biodiesel is still above 75%. The main quality indexes of the product can reach the biodiesel B100 standard completely.