USY分子筛上苯与多仲丁苯烷基转移反应

Transalkylation of benzene with multi-secbutylbenzene over USY zeolite

在微型固定床反应器上研究USY分子筛对苯与多仲丁苯烷基转移反应的催化性能,考察反应温度、原料配比和空速等工艺条件对反应的影响。采用NH3-TPD、吡啶IR吸附和N2吸附-脱附等手段对USY分子筛酸性质和孔结构进行表征。结果表明,USY分子筛在烷基转移反应中具有较好的催化性能,二仲丁苯转化率为87.7%,三仲丁苯转化率为19.3%,仲丁苯选择性为91.38%,与USY分子筛的多级孔道和较多B酸位有关。多仲丁苯转化率和仲丁苯选择性随反应温度的提高而增大,原料中苯的增加可提高仲丁苯选择性,空速对二仲丁苯转化率影响较小,但对仲丁苯选择性和三仲丁苯转化率影响显著。USY分子筛上反应较适宜的工艺条件为:反应温度240℃,反应压力3 MPa,苯与二仲丁苯物质的量比16,二仲丁苯空速1.4 h-1。

The catalytic properties of USY zeolite for transalkylation of benzene with multisecbutyl benzene and the effects of reaction temperature, raw material composition, and space velocity of disecbu tylbenzene on the transalkylation of muhisecbutylbenzene process were investigated in a fixed bed micro reactor. The acidity properties and pore structure of USY zeolite were characterized by NH3TPD, IR spec tra and N2 adsorptiondesorption. The results showed that USY zeolite possessed good catalytic perform ance in the transalkylation reaction, and the conversion of disecbutylbenzene and trisecbutylbenzene, and the selectivity to secbntylbenzene were 87.7%, 19.3% ,91.38% ,respectively, since there were hierar chical channels and plenty of strong Bronsted acid sites in USY zeolite. Both the conversion of multi secbutylbenzene and the selectivity to secbutylbenzene were increased with the enhancement of reaction temperature. Increasing the amount of benzene in the raw material could enhanced the selectivity to secbu tylbenzene. The space velocity of diseebutylbenzene had little influence on disecbutylbenzene conversion and great influence on the conversion of trisecbutylbenzene and the selectivity to secbutylbenzene. The optimum reaction condition of benzene transalkylation with muhisecbutylbenzene over USY zeolite were as follows：reaction temperature 240 ℃, reaction pressure 3 MPa, benzene/disecbutylbenzene molar ratio16, di-secbutylbenzene space velocity 1.4 h-1.