改性ZSM-5上苯与乙醇烷基化反应条件的考察及再生评价

Study on experimental conditions and regeneration performance of modified ZSM-5 in benzene alkylation with ethanol

通过离子交换法制备出一种钛改性的分子筛,并在连续流动固定床反应器上对其进行了苯与乙醇烷基化反应条件和催化剂的失活再生评价。通过XRD、BET、NH3-TPD、Py-IR和ICP方法对催化剂进行了表征,结果表明,改性后催化剂的比表面积、微孔孔容和孔径均减少,B酸/L酸比值增加,改性元素含量8.56%。反应评价结果显示,改性后乙苯选择性略有降低,苯的转化率增加,乙醇利用率增加。改性催化剂的最佳反应条件:温度360～460℃,质量时空速3～5h-1,苯醇摩尔比3～5。催化剂4次再生评价效果良好,再生后酸性没有太大改变,是一种具有良好工业应用前景的催化剂。

Alkylation of benzene with ethanol was investigated over Ti ion exchanged modified HZSM-5 molecular sieves catalyst. The catalysts were characterized by XRD, BET, NH3-TPD, Py-IR and ICE The pore diameter, BET surface area and micropore volume of the modified catalyst decreased after modification. The ratio of B acid and L acid of the modified catalyst increased. The Ti loading amount was 8.56%. According to the results from reaction tests, the ethylbenzene selectivity of the modified catalyst decreased a little, the benzene conversion and ethanol utilization increased. The effects of temperature, feed ratio, WHSV were also investigated. The appropriate temperature was 360-460℃, the mol ratio of benzene and ethanol was 3-5 and WHSV was 3-6 h^-1. The regenerated catalyst maintained high activity and its acid property did not change much. The catalyst had good prospect of industrial application.