Straight-run Naphtha Aromatization Modified Catalyst For The Development Of Its Coking Deactivation Regular

We reasearched the effect on the property of zeolite catalyst about the condision of preparte catalyst. The catalyst samples were characterized by XRD, IR,GC and measurement of nitrogen isotherms of adsorption-desorption.The analysis result showed that the phase has nothing change as HZSM-5 zeolite catalyst modified by Zn,Al,Ga etal,but the pore volume ,sueface area,acid amount decrease. The conversion rate of heptane on the zeolite catalyst decrease.The aromatic hydrocarbon yield and selectivity increase.Among of the catalyst of ZnHZSM-5, A1HZSM-5 and GaHZSM-5, ZnHZSM-5 zeolite obtained the optimal result. Therefore researched the relation both content of Zn in ZnHZSM-5 zeolite and aromatization activity, the content of Zn in 2% is more avail to heptane aro—matization. Researched the effect on different temperature strem treatment of ZnHZSM-5 zeolite catalyst.,result showed that arimatic activity , surface area decrease of ZnHZSM-5 zeolite catalyst; stabilization and pore volume increase of ZnHZSM-5 zeolite catalyst.In a small-scale isothermal fixed bed reactor researched the deactive disciplinary on deposition of coke on ZnHZSM-5 zeolite catalyst by Zhong Yuan stright distal Naphtha aromatization. Determined the structure and property on deposition of coke on ZnHZSM -5 zeolite catalyst by TG, GC, NH3-TPD, XRD and H/Cetal. In the condition of microtherm and/or low content coke deposition on ZnHZSM-5 zeolite catalyst, H/C of coke is higher, the coke is Aliphatic compound; In high temperature or/and high content coke deposition on ZnHZSM-5 zeolite catalyst, H/C of coke is lower, the structure of coke is similar to graphite. The deposition coke covered acidic size and built up pore volume ZnHZSM-5 zeolite catalyst, this result in deactivation of ZnHZSM-5 zeolite catalyst.Researched the connection both reactive condition and the amounts of deposition on ZnHZSM-5 zeolite catalyst. Based on the experiment result, the equation was suggested on the amounts of coke deposite changes with time:C_c=0.118t^0.683 The temperature has crucial effect on coke deposition on ZnHZSM-5 zeolite catalyst.