SO_4^(2-)/TiO_2-V_2O_5催化废油脂制备生物柴油

SO_4^(2-)/TiO_2-V_2O_5 CATALYZED PRODUCTION OF BIODIESEL FROM WASTE EDIBLE OIL

采用溶胶凝胶法和浸渍法制备SO_4^(2-)/TiO_2-V_2O_5固体超强酸催化剂,并考察了其在废油脂制备生物柴油中的催化性能。运用XRD、比表面积、全硫测定、酸性测定等表征了催化剂。钒的引入延迟了基体氧化物的晶化,并使催化剂粒径减小,比表面积增大,有效抑制了催化剂中硫的流失,进而增强酸性中心。SO_4^(2-)/ TiO_2-V_2O_5催化剂试样对制备生物柴油有较高的催化活性,在催化剂用量为原料油质量的4%、n(乙醇):n (废油脂)=1 5:1、反应温度220℃、反应时间10 h的条件下,生物柴油收率可达79%以上。催化剂重复使用5次,生物柴油收率在75%以上。

Solid super acid SO4^2-/TiO2-V2O5 was prepared by a sol-gel and impregnation method and characterized by XRD, BET surface area, chemical analysis, etc. The introduction of V delays the crystallization of the matrix oxide, decreases the particle＇s diameter, enlarges the surface area, inhibites the loss of sulfur from the catalysts and enhances acid and active sites. The catalyst shows relatively high activity in the reaction. Under conditions of 4.0% catalyst, mole ratio of methanol to oil 15 ： 1, reaction temperature 220℃ and reaction time 10 h, the yield of biodiesel is up to 79%. The catalyst can be repeatedly used for 5 times with the yield of biodiesel still up to 75%.