| Ethylene production via ethanol dehydration over solid acid catalysts has recently attracted much more attention because the process is environmental, sustainable and the operation conditions are mild in comparison with hydrocarbon decomposition. The thesis focused on the ethylene production through ethanol dehydration, and the content is as follows: WO3/HZSM-5 zeolite was prepared by mechanical mixing method or impregnant method, and the ethanol conversion and the ethylene selectivity over these synthesized catalysts were then studied. Effects of operation conditions on the catalytic activity were also studied here. Characterization of NH3-TPD,IR,BET,XRD,Raman and XPS were used to study the influence of the catalyst surface acid and structure property on the ethanol dehydration reaction.As far as the mechanically mixed WO3/HZSM-5 is concerned, WO3 content played an important role on the catalysts activity. The activity test results showed that 10wt% WO3/HZSM-5 exhibited the best dehydration activity. Compared with HZSM-5 zeolite, the ethanol conversion increased from 72.3% to 90.8%, and the ethylene selectivity increased from 66.0% to 67.7%. Characterization results of NH3-TPD and Py-IR showed that the loaded WO3 decreased the acidity of the catalyst and the Lewis acid disappeared. The Raman and XPS results showed the W species in 15wt% WO3/HZSM-5 exhibited accumulation on the catalyst surface. The XPS results showed there were only W5+ detected in 10wt%WO3/HZSM-5 and W4+ and W6+ detected in 15wt% WO3/HZSM-5. W5+ probably contributed to the high dehydration activity of 10wt% WO3/HZSM-5.Considering impregnated WO3/HZSM-5, the effects of WO3 content, calcined temperature and calcined time of the prepared catalysts were investigated using the orthogonal experiment method. The results showed that WO3 content influence the catalyst activity obviously. 5wt% WO3/HZSM-5 exhibited the best dehydration activity. The ethanol conversion is 83.8%, and the ethylene selectivity is 70.6%.
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