甲苯-甲醇在改性HZSM-5催化剂上烷基化生产对二甲苯

ALKYLATION OF TOLUENE WITH METHANOL ON MODIFIED HZSM-5 CATALYST TO PRODUCE P-XYLENE

本文研究了用磷、钙改性HZSM-5分子筛对甲苯-甲醇选择性烷基化反应生产对二甲苯的催化性能。考察了不同磷或钙含量及磷和钙总量对改性HZSM-5分子筛催化性能的影响。结果表明,用磷和钙改性的HZSM-5分子筛,CaO比P_2O_5对提高分子筛的对位选择性影响更大。改性的HZSM-5分子筛中的适宜CaO含量为10～15m％,CaO+P_2O_5总量为19～22m％。较佳的CaO和P_2O_5含量均为10m％。在450℃、空速10.5h^(-1)下,对二甲苯选择性为93％,甲苯转化率为17.1mol％,对二甲苯产率为15.2mol％。本文还考察了反应温度和空速对催化性能的影响。

The reaction characteristics in selective alkylation of toluene with methanol on HZSM-5 zeolites modified with phosphorus and calcium for the production of para-xylene(PX) have been studied.The influenees of the contents of P_2O_5,CaO and P_2O_5 plus CaO on the reaction characteristics of mcdified HZSN-5 are investigated. The results show that CaO is nacre effective than P_2O_5 in enhancing PX selectivity of HZSM-5 catalyst modified with both P_2O_5 and CaO.The appropriate dosages of CaO and CaO plus P_2O_5 in HZSM-5 are 10～15m% and 19～22m%, respectively. HZSM-5 modified with 10m% P_2O_5 and 10m% CaO gaves fairly good performance with a PX selectivity of 93% ,toluene conversion of 17.1 mol% and PX yield of 15.2 mol%at 450℃ and 10.5 WHSV.The effect of reaction temperature and WHSV are also studied.