催化精馏合成异丙苯过程催化剂装填结构研究

Study on Catalyst Packing Structure in Catalytic Distillation Process for Cumene Synthesis

为考察不同催化剂装填结构对催化精馏合成异丙苯过程的影响 ,在热态反应器中进行苯烃化催化精馏合成异丙苯的研究。反应器直径为 3 0mm ,高 2 0 0 0mm ,所用催化剂为 β改性沸石分子筛。操作压力0 .7MPa ,温度 43 0— 480K ,苯质量空速 4— 6h- 1 ,苯烯摩尔比 1.1— 2 .2 ,回流比 9— 2 0。催化剂装填结构由不锈钢填料与催化剂颗粒组成 ,三种装填结构的空隙率分别为 85 .1% ,81.6%和 79.4%。结果表明 ,对于异丙苯合成体系 ,装填结构对催化精馏的总体效果起决定性影响。在催化剂装填总量不变的前提下 ,异丙苯的选择性与丙烯的转化率均随催化剂装填结构空隙率的提高而提高。在优化条件下 ,异丙苯的选择性达97% ,丙烯转化率接近 10 0 %。

Different catalyst packing structures were investigated in the process of catalytic distillation for producing cumene. The experiment was performed in the heat laboratory-scale column whose diameter is 30 mm and height is 2000 mm. Catalyst is improved to be beta zeolite. Operating pressure is 0.7MPa; temperature is from 430K to 480K; space velocity of benzene is 4-6h -1; mole ratio of benzene vs. propylene is 1.1-2.2; reflux ratio is 9-20. The catalyst packing structure is composed of stainless steel packing and catalyst particle. The void of three catalyst-packing structures is 85.1%, 81.6% and 79.4% respectively. As for cumene production, it is proved that the void of catalytic packing structure has dominant effect on the result of chemical reaction and separation. By keeping the total amount of catalyst unchanged, selectivity of cumene and conversion of propylene increases with the void of catalyst packing structure. In the optional conditions, selectivity of cumene can be high as 97%;conversion of propylene is nearly 100%. The influence of catalyst packing structure on selectivity of cumene is more remarkable than that on conversion of propylene.