پديدآورندگان :
Baradaran Soroush Chemical Engineering Department, Amirkabir University of Technology, Hafez Avenue, Tehran, Iran. , Sohrabi Morteza Chemical Engineering Department, Amirkabir University of Technology, Hafez Avenue, Tehran, Iran. , Moghimpour Bijani Parisa Catalyst Research Group, Petrochemical Research and Technology Company, National Petrochemical Company, Tehran, Iran. , Royaee Sayed Javid Refining Technology Development Division, Research Institute of Petroleum Industry, Tehran,Iran
كليدواژه :
ZSM , 5 , pH , Hydrothermal synthesis , Propane Aromatization , Aromatics selectivity
چكيده فارسي :
Effect of alkalinity on the hydrothermal synthesis of ZSM-5 zeolite using TEOS as the Si source, TPABr as the template and NaAlO2 as the Al source was studied. Formation of the crystal phases was investigated throughout X-Ray Diffraction. BET, SEM and NH3-TPD techniques were also applied for product characterization. The results indicated the significant effect of the hydrogel alkalinity on the product specifications. Actually, different levels of alkalinity can hinder formation of crystalline phase or result in growth of other phases which are more stable than ZSM-5. An optimum of 9.7 was found for pH value leading to formation of ZSM-5 crystals with appropriate crystallinity. The catalytic performance test of the prepared H-ZSM-5 was carried out in fixed-bed reactor at 550°C. The obtained data showed a conversion of 68% for propane while the selectivity towards aromatics was 37%. A gradual decreasing trend in both of the terms was also observed which implies the preferential deactivation of active sites
