混合二元酸多相催化酯化反应研究

设计了一套固定床多相催化酯化反应方案,用环己烷氧化制己二酸生产过程中的副产物混合二元酸(含有己二酸、戊二酸、丁二酸等组分)和甲醇为反应物,采用不同离子交换分子筛作催化剂进行酯化反应研究。这种反应方式可以使气体甲醇和混合二元酸在常压、高温下进行,而且不存在催化剂与产物的分离问题;反应生成的液态酯由于重力作用从反应器底部流出而得以分离,而反应生成的水蒸汽和未反应的甲醇蒸汽直接从反应器上部采出,使酯化率明显提高。实验结果表明,实验方案是可行的,分子筛的结构对酯化催化活性没有明显影响,但分子筛催化剂酸性越强酯化效果越好,其中ReHY具有更高的催化酯化活性,酯化率达到6 8.1%。

Heterogeneous Catalyitc Esterification Reaction for Mixed Dibasic Acid

A fixed-bed of heterogeneous catalytic system was designed. Esterification reaction of methanol with mixed dibasic acid (contains adipic acid , glutaric acid,and succinic acid and so on), which is a by-product in process of producing adipic acid from oxidizing cyclohexane was researched. A various of molecular sieve catalyst modified by means of ion exchange was adopted in the experiment. The reaction between methanol steam and solid mixed dibasic acid may be completed under normal pressure and higher temperature conditions in the heterogeneous system, in which the liquid esters produced may flow down from the reactor bottom and be easily separated, and the water steam formed and methanol steam unreacted may flow up from the top reactor and be removed from solid catalyst so that esterification is enhanced. The experimental results show that the method is feasible, and molecular sieve catalyst structures have little effect on catalytic esterification efficiency.The stronger acid catalyst is, the higher esterizing rate is. ReHY has a higher catalytic activity, and esterification rate reaches up to 68.1%.