乙醇在催化裂化催化剂上催化脱水反应性能的研究

STUDY ON THE CATALYTIC DEHYDRATION OF ETHANOL TO ETHYLENE OVER FCC CATALYSTS

在小型固定流化床反应装置上使用三种不同的催化裂化催化剂进行乙醇催化脱水制乙烯反应性能的研究,并对其反应化学及反应机理进行初探。结果表明,在反应温度为360℃、进料重时空速为1.25 h^(-1)的实验条件下,A,B,C 三种催化剂均表现出较好的催化脱水制乙烯反应性能,乙醇催化脱水反应的转化率均大于99%,烃类产物中乙烯体积分数均大于98%,乙烯产率均大于60%;并且催化剂 C 具有较好的活性稳定性。乙醇在分子筛催化剂上催化脱水反应过程遵循正碳离子机理,较好地解释了主要产物乙烯、丙烯和丙烷的生成机理。

The experiments of catalytic dehydration of ethanol were carried out in a bench scale fixed-fluidized bed（FFB）unit over three FCC catalysts. The reaction chemistry and reaction mechanism of catalytic dehydration of ethanol to ethylene were discussed. The experimental results showed that at a reaction temperature of 360 ℃ and a WHSV of 1.25 h^-1 ,these three FCC catalysts all exhibited excellent catalytic performance of ethanol dehydration,the conversion of ethanol was more than 99% ,the volume percent of ethylene in the product was more than 98% and the yield of ethylene was more than 60%. It was found that the dehydration of ethanol over zeolite catalyst followed carbonium ion reaction mechanism,and thus the formation of ethylene, propylene and propane as the main products was well explained.