以环氧氯丙烷(ECH)为连接剂,将硅酸钠(Na2SiO3)化学固定于壳聚糖季铵盐(HTCC)分子链上,制得一种硅酸钠/壳聚糖季铵盐有机无机杂化膜(HTCC/Na2SiO3/ECH),作为固体碱催化剂催化大豆油和甲醇进行酯交换反应制备生物柴油,该膜显示出良好的重复使用性,并根据中心组合响应面法对影响生物柴油转化率的条件(反应温度、反应时间、醇油质量比以及催化剂用量)进行优化,确定催化膜催化酯交换反应制备生物柴油的二阶多项式模型和反应因素影响显著性顺序.结果表明:反应温度55℃,醇油摩尔量比6:1,催化膜含量为油重的质量分数49/6,反应时间60min,预测转化率为98.0%,实际值为97.1%,与实际值基本相符,表明优化模型有效可靠.
An organic inorganic hybrid membrane (HTCC/Na2 SiO3/ECH) containing sodium silicate and N- [ (2 - Hydroxy- 3 - trimethylammonium) propyl] chitosan chloride (HTCC) with epichlorohydrin (ECH)as cross-linking agent was employed as a heterogeneous base catalyst lor blodlesel production prepared from soybean and methanol. HTCC/Na2 SiO3/ECH membranes exhibited the excellent catalytic stability. The factors of temperature, reaction time, molar ratio of methanol to oil and reaction time were optimized by the response surface methodology with HTCC/Na2 SiOa/ECH membranes. A second order quadratic equation and the significant sequence of factors were built. The results showed that the optimum condition were: temperature at 55 ℃, methanol/oil molar ratio of 6 : 1, catalyst amount of 4 wt% and reaction time of 60 min. The predicted conversion rate to biodiesel was 98. 0%, which was in consistent with the experimental value (97.1%). Thus, the regression equation was valid and reliable.