大孔沸石催化剂上苯与丙烯液相烷基化反应行为的研究

LIQUID PHASE ALKYLATION OF BENZENE WITH PROPYLENE OVERLARGE PORE ZEOLITE CATALYSTS

围绕具有工业实用价值的苯与丙烯液相烷基化制取异丙苯这一课题，对比考察了不同硅铝组成的ＨＹ型和Ｈβ型沸石的催化性能，利用烧炭试验、结炭前驱物萃取方法及色－质谱表征手段探索了沸石催化剂在烷基化反应中的结炭行为。烷基化试验结果表明，β沸石对异丙苯的选择性和催化剂稳定性都明显优于Ｙ型，其异丙苯选择性可达９６ｍｏｌ％以上。同时，提高原料苯烯比、降低反应温度或保持适当高的进料空速能够提高异丙苯的选择性。结炭催化剂的烧炭结果显示，在烷基化反应中Ｈβ比ＨＹ具有较强的抗结炭能力。结炭催化剂的溶剂萃取结果表明，反应中的液相苯能够有效地使催化剂孔道中的结炭前驱物种脱离催化剂表面，从而抑制结炭。

Liquid phase alkylation of benzene with propylene has been investigated over HY H zeolites of various silicon and aluminum compositions According to the results from reaction tests, H zeolite shows better catalytic properties in both cumene selectivity and catalyst stability, and the selectivity for cumene is over 96 mol% The cumene selectivity can be improved by using high benzene/propylene ratio in feed, proper reaction temperature or slightly high feeding speed The results from the calcination tests of coked catalysts indicate that H shows a stronger ability than HY of resisting coking in the alkylation As evidenced in GC-MS determination, a variety of organic precursors of cokes have been extracted from the channels of H catalyst by using benzene as a solvent This result indicates that the flowing benzene in the liquid alkylation system can effectively carry the coke precursors off the active sites of catalyst and therefore prolong the lifetime of catalyst