玉米粉炭基固体酸催化合成生物柴油动力学研究

Reaction kinetics of biodiesel catalyzed by a carbon-based solid acid catalyst prepared from maize starch

以玉米粉炭基固体酸作为催化剂,催化油酸与甲醇进行酯化反应制备生物柴油,在催化剂和甲醇用量一定的条件下,考察了不同反应温度下不同反应时间对油酸转化率的影响;并根据油酸浓度与时间的关系曲线,用微分法建立油酸酯化反应动力学的数学模型,计算相关的动力学参数。实验结果表明:在剂油比9%(催化剂质量占油酸质量的分数)、醇酸物质的量比8∶1、反应温度68℃、反应时间10 h时,油酸转化率最高可达到90.09%。该反应的反应级数为1.683,活化能为6.23×10~4J/mol,频率因子为2.17×10^(13)mol^(-0.683)·L^(0.683)·h^(-1)。

A carbon-based solid acid catalyst prepared from maize starch has been used to catalyze the esterification of oleic acid with methanol to produce biodiesel. The effects of varying the reaction time at different reaction temperatures on the conversion of oleic acid were investigated for fired amounts of catalyst and methanol. From the plots of oleic acid concentration against time,a mathematical model of oleic esterification reaction kinetics was established using a differential method,and the relevant kinetic parameters were calculated. The results showed that the oleic acid conversion reached to 90. 09% after 10 h at a reaction temperature of 68 ℃ when the mass ratio of catalyst to oleic acid was 9% and the molar ratio of methanol to oleic acid was 8∶ 1. The kinetic study showed that the reaction order was 1. 683 with an activation energy of 6. 23 × 10^4 J/mol and frequency factor of 2. 17 × 10^（13）mol^（-0.683）·L^（0.683）·h^（-1）.