Zn/Al复合氧化物催化剂用于菜籽油甲醇酯交换反应制备生物柴油

Using Zn/Al Binary Metal Oxides in the Transesterification of Rapeseed Oil and Methanol for Biodiesel Production

固体催化剂用于酯交换反应制备生物柴油具有易分离、流程简单的优点,制备了Zn/Al水滑石,以其为前驱体经煅烧制得了Zn/Al复合氧化物酯交换催化剂。用XRD、TG/DTA、XPS、AAS、BET等技术对催化剂结构进行了表征。结果表明,大的比表面积、均匀的孔结构和活性组份ZnO的良好的分散状态可以提高Zn/Al复合氧化物催化剂的反应活性。经400℃煅烧8 h制得的Zn/Al复合氧化物催化剂,在200℃、3.3 MPa、油/醇质量比为7∶10、1.4(wt)%催化剂用量的条件下,在3 min内油脂转化率达到89.1%。

Solid catalysts are easily separated from biodiesel product, and therefore using solid catalysts can greatly simplify the process of biodiesel production. Zn/Al hydrotalcite was prepared and it was served as the precursor of Zn/Al compound metal oxide catalyst. Calcining Zn/Al hydrotalcite at 400 ℃ for 10 h obtained the catalyst, which achieved a oil conversion as high as 89.1% within 3 minutes under the conditions of 200 ℃, 3.3 MPa, 70 g refined rapeseed oil, 100 g methanol, and 1.4 （wt） % catalyst dosage. Furthermore, XRD, TG/DTA, XPS, AAS and BET measurements were used in the characterization of the catalysts. The results show that a high specific surface area and an optimal pore structure are necessary in order to obtain a high dispersion of active component as well as a high activity.