固体酸催化棉籽油酯交换制备生物柴油

生物柴油(脂肪酸甲酯)可以由棉籽油与甲醇在酸催化剂的作用下通过酯交换反应制得. 通过硫酸改性氧化钛、氧化锆，并经过高温煅烧得到了相应的固体强酸催化剂TiO2-SO42-, ZrO2-SO42-，并对催化剂活性进行了评价. 实验结果表明，TiO2-SO42-和ZrO2-SO42-与改性前的氧化物相比具有较高的酯交换反应活性. 在230℃、醇油摩尔比12:1及催化剂用量为棉籽油2%(w)的条件下，反应8 h后甲酯的收率达到90%以上. 与固体碱催化剂相比，固体酸催化剂对原料的酸度有更强的适应性. 红外吡啶吸附光谱表明，TiO2-SO42-与ZrO2-SO42-具有较强的L酸和B酸中心.

Biodiesel Preparation from Transesterification of Cotton Seed Oil by Solid Acids Catalysis

Methyl esters (biodiesel) were produced by transesterification of cottonseed oil with methanol in the presence of solid acids as heterogeneous catalyst. The solid acids were prepared by mounting H2SO4 on TiO2×nH2O and Zr(OH)4, respectively, followed by calcining at 823 K. TiO2-SO42- and ZrO2-SO42- were employed as catalyst for transesterification with high activity. The yield of methyl esters reached over 90% under the conditions of 230℃, methanol/oil mole ratio of 12:1, reaction time 8 h and catalyst dosage (catalyst/oil) of 2%. The solid acid catalysts have more adaptability than the solid bases catalysts when the oil has high acidity. Spectral analysis of absorbing pyridine IR of the samples showed that there were Lewis and Bronsted acid centers on the catalysts.