【摘要】 通过催化剂表征和小型固定床反应发现,减小沸石晶粒度和提高沸石表面L酸B酸比值,或者适当采用高氢油比,可以提高ZSM-5沸石在汽油芳构化降烯烃反应中的活性稳定性.而适当提高反应温度及减小汽油进料空速则可以提高汽油中烯烃的芳构化程度.连续300h的小试运转表明,FCC和DCC汽油中的烯烃在一种晶粒度为20～50纳米的改性纳米ZSM-5沸石上可有效地转化为芳烃,降烯烃幅度达20个体积百分点以上,改质后汽油的辛烷值、组成和沸程等指标均满足新国标要求.更多还原

【Abstract】 The present study is focused on the conversion of gasoline olefins to aromatics （OTA） over ZSM-5 zeolite. Results show that the catalytic performance of a ZSM-5 zeolite is closely related to its crystal size, surface acidity and reaction conditions like temperature, weight-hourly-space- velocity (WHSV_oil) of oil feed and hydrogen-oil ratio （H₂/oil）. Generally, the resistance of ZSM-5 zeolite against deactivation can be enhanced by decreasing its crystal size, or by increasing Lewis acid sites to Bronsted acid sites ratio, or by adopting high H₂/ oil ratio. While the extent of OTA reaction can be favored by employing high reaction temperature or small WHSV_oil value. By feeding fluidized catalytic cracking （FCC） gasoline and deep catalytic cracking （DCC） gasoline to a modified nano-HZSM-5 zeolite （crystal size 20⁵0 nm, silica to alumina molar ratio 25, Lewis acid sites to Bronsted acid sites ratio 3.5） under suitable conditions as defined by reaction temperature 370 390 ℃, reaction pressure1.6³.0 MPa, WHSV_oil 3⁶ h^-1, H\-2/ oil ratio 600 （v/v） and catalyst loading 2 g, it was seen that more than 20 percentages of the olefins in both FCC gasoline and DCC gasoline could be converted. The aromatics contents of the upgraded gasolines confirm OTA as main reaction path. In 300 hours time-on-stream, the modified nano-sized ZSM-5 zeolite maintains its OTA reaction activity well, which guarantees the upgrade of the gasolines successful not only in terms of reduction of olefin content, but also in terms of octane number maintaining. These results indicate that nano-HZSM-5 zeolite has bright foreground in developing commercial gasoline olefins abating catalyst.更多还原