摘要
对工业中试用于苯与丙烯烷基化失活β 沸石改性催化剂进行了H2 再生研究。通过对失活、新鲜和再生后催化剂的TPO、TPD、孔结构测定和活性评价以及失活和再生催化剂样品上炭组成的GC MS分析 ,讨论了H2 再生后催化剂催化性能的恢复状况。解释了虽然仍有部分炭未被除去 ,但酸性和活性恢复良好的原因。提出了本文体系失活催化剂H2 再生过程的作用机理。
Deactivated zeolite-β based catalyst used in middle-size industrial test for benzene alkylation with propylene was studied under the H 2 regeneration condition. Effect of H 2 in regeneration process was discussed by comparing TPO, TPD, pore structure, activity evaluation of the fresh, the deactivated and the regenerated catalyst and analysis of coke component on deactivated and regenerated catalyst by GC-MS. The reason of acid sites and activity having good resumption on regenerated catalyst is explained although there still are some coke on it. The reason is that the dissoluble-coke comes of from the surface of the catalyst under the affect of H 2, a lot of surface is renewed. While the non-dissoluble-coke do not cover large area of pore surface (it mainly occupies volume of pore), so the non-dissoluble-coke has no large effluence on adsorption of probe molecule and adsorption reaction of react molecules on activity sites of catalyst. The result is that activity sites and reaction activity has been resumed satisfactorily. Mechanism of H 2 regeneration process is advanced. That is: Under this paper condition, H 2 firstly diffuses to the pore surface of the catalyst, and surface chemical affect is occurred in here at high temperature, it weakens adsorption affect between activity sites and dissoluble-coke. So the dissoluble-coke comes off from the activity sites on pore surface of the catalyst easily. A lot of dissoluble-coke comes off from the activity sites by such process, and then it is dissolved in liquid benzene flow. Suitable size molecule is carried out from the pore by the benzene flow, large size molecule can not be carried out from the pore, it still stays in the pore. Strong Brosted sites have adsorbed a lot of coke, and the coke is adsorbed too strong to come off from the sites, to form non-dissoluble-coke, H 2 does not act on the coke. Thus strong Brosted sites do not be resumed by H 2 regeneration process satisfactorily.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2002年第1期58-63,共6页
Journal of Fuel Chemistry and Technology
