固体酸WO_3/ZrO_2制备生物柴油的研究

Research on producing biodiesel over solid acid catalyst WO_3/ZrO_2

采用共沉淀法制备了固体强酸WO_3/ZrO_2,研究了WO_3负载量和焙烧温度对催化剂晶相和比表面积的影响,并且研究了WO_3/ZrO_2催化剂对葵花籽油酯交换反应制备生物柴油(BDF)的催化性能,结果表明,WO_3/ZrO_2催化剂的催化性能与WO_3负载量及晶相结构密切相关,在负载量为0.1 g WO_3/ZrO_2时,经700～800℃高温焙烧,WO_3在ZrO_2表面上达到单层分散,且大部分ZrO_2以四方晶相存在,而四方相的存在对于形成WO_3/ZrO_2的强酸性是很重要的。所制备的催化剂具有较好的催化活性,在反应温度150℃、醇油物质的量比12:1及催化剂用量为葵花籽油质量分数的3%的条件下,反应8 h后葵花籽油的转化率可以达到60%以上。

In this study, the solid acid catalyst WO3/ZrO2 was synthesized by the coprecipitation method. The effects of WO3 loading and calcination temperature on the crystalline phase and specific surface area of catalysts were investigated. The catalytic performance of WOa/ZrO2 for transesterification of sunflower seed oil and methanol was studied. When the WO3 loading was 0. 1 g WO3/g ZrO2, Via roasting at 700 --800 ℃, the WO3 dispersion on ZrO2 became monolayer, most of ZrO2 presented in tetragonal crystalline phase. The formation of the tetragonal ZrO2 crystalline phase, as well as the WO3 dispersivity on ZrO2, was dependent on the WO3 loading and calcination temperature. The convertion of oil reached over 60% under the conditions of 150℃,methanol/oil mole ratio of 12 ： 1, reaction time 8 h and catalyst dosage（catalyst/oil） of 3%.