ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve...ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve were characterized by X-ray powder diffractometry,N_2 adsorption isotherms,temperature programmed desorption of ammonia and scanning electron microscopy and their properties were analyzed.Using FCC gasoline as the feed,activities of different molecular sieves for reducing olefin content were investigated in a continuous high-pressure micro-reactor unit under the following conditions:a reaction temperature of 400℃,a reaction time of 2 h,a weight hourly space velocity of 3h^(-1),and a reaction pressure of 2.0 MPa.The results showed that the HMCM-41 molecular sieve had low reaction performance,and the HZSM-5 molecular sieve demonstrated high aromatization activity,while the ZSM-5/MCM- 41 composite molecular sieve exhibited a best olefin-reducing performance because of its high isomerization activity and moderate aromatization activity.With a largest olefin-reducmg capability and a reasonable distribution of products,the composite molecular sieve was more suitable for FCC gasoline upgrading compared to other three catalysts.展开更多
The use of a modified ZSM-5 molecular sieve to remove thiophene from benzene was demonstrated. Adsorption equilibrium experiments were carried out in an enclosed vessel in which a known amount of zeolite was contacted...The use of a modified ZSM-5 molecular sieve to remove thiophene from benzene was demonstrated. Adsorption equilibrium experiments were carried out in an enclosed vessel in which a known amount of zeolite was contacted with 20-40 ml of benzene-thiophene solution. The solutions were analyzed by gas chromatography with flame photometric detector. Thiophene was not physically adsorbed on a single molecular layer but mainly adsorbed chemically onto the modified ZSM-5 zeolite adsorbent.展开更多
文摘ZSM-5/MCM-41 composite molecular sieve was prepared by the nano-assembling method.The ZSM-5 molecular sieve,the MCM-41 molecular sieve,the ZSM-5/MCM-41 mechanical mixture and the ZSM-5/MCM-41 composite molecular sieve were characterized by X-ray powder diffractometry,N_2 adsorption isotherms,temperature programmed desorption of ammonia and scanning electron microscopy and their properties were analyzed.Using FCC gasoline as the feed,activities of different molecular sieves for reducing olefin content were investigated in a continuous high-pressure micro-reactor unit under the following conditions:a reaction temperature of 400℃,a reaction time of 2 h,a weight hourly space velocity of 3h^(-1),and a reaction pressure of 2.0 MPa.The results showed that the HMCM-41 molecular sieve had low reaction performance,and the HZSM-5 molecular sieve demonstrated high aromatization activity,while the ZSM-5/MCM- 41 composite molecular sieve exhibited a best olefin-reducing performance because of its high isomerization activity and moderate aromatization activity.With a largest olefin-reducmg capability and a reasonable distribution of products,the composite molecular sieve was more suitable for FCC gasoline upgrading compared to other three catalysts.
基金Supported by the Post-Doctorate Science Foundation of China.
文摘The use of a modified ZSM-5 molecular sieve to remove thiophene from benzene was demonstrated. Adsorption equilibrium experiments were carried out in an enclosed vessel in which a known amount of zeolite was contacted with 20-40 ml of benzene-thiophene solution. The solutions were analyzed by gas chromatography with flame photometric detector. Thiophene was not physically adsorbed on a single molecular layer but mainly adsorbed chemically onto the modified ZSM-5 zeolite adsorbent.
