AB-97分子筛催化剂上苯与乙烯烷基化反应 Ⅲ.失活动力学及失活特征

Study on Ethylbenzene Synthesis over AB-97 Zeolite Ⅲ.Deactivation Kinetics

用催速失活的方法研究了AB -97分子筛催化剂的失活动力学。实验表明 ,催化剂的失活过程具有逆选择性失活特征。由失活动力学对催化剂稳定性的模拟计算可知 ,乙烯空速对催化剂稳定性的影响分为两个阶段 :在低空速阶段 ,随空速的减小 ,稳定期显著增加 ;在高空速阶段 。

Deactivation kinetics of AB-97 alkylation zeolite was studied in a plug flow reactor by means of accelerated deactivation.A deactivation kinetics model was obtained by parameter estimation and was revised by comparison with macro-kinetics.Statistical calculations proved that the kinetic model was proper.The partial pressure index of ethylene was rather large indicating that ethylene was the key factor affecting the deactivation process.The catalyst deactivation trend showed that the deactivation was of the type of counter-selectivity having the characteristic of being able to maintain a considerably long period of stable activity.This deactivation kinetics was used to simulate the catalyst activation stability of 6-layer alkylation reactor.The simulation result showed that the effect of ethylene space velocity on catalyst stability could be divided into two stages.At the stage of low space velocity,the stability of the catalyst increased sharply with decrease in space velocity;and at the stage of high space velocity,catalyst life almost remained constant with respect to changes in space velocity.