MDA Reaction Performance Of Acid-base Modified Mo/HZSM-5 And Optimization Of MDA Reaction Process Parameters On Fixed Bed

The methane non-oxidative aromatization reaction(MDA)is the subject of this study.The change of physicochemical properties of HZSM-5 molecular sieves treated with different modified solutions was investigated and its effect on the performance of methane non-oxidative aromatization of Mo/HZSM-5 catalysts.Then,the spherical 6 wt.% Mo/HZSM-5 supplied by Japan Denso Co.,Ltd.was used as an aerobic aromatization catalyst for methane.Different reaction space velocity,catalyst particle size and reaction temperature were investigated for Mo/HZSM-5 effect of benzene formation rate on the catalyst.On this basis,the benzene production within 100 min was used as an inspection index to establish orthogonal experiments.Determination of optimum process parameters for methane non-oxidative aromatization of 6 wt.% Mo/HZSM-5 catalyst in a fixed bed.The results shwo:(1)The use of different concentrations of sodium hydroxide,ammonia,hydrochloric acid,and sodium carbonate solutions to modify micron or nanoscale HZSM-5 molecular sieves.On the one hand,the acidity of the HZSM-5 molecular sieve can be modulated;on the other hand,the pore properties of the HZSM-5 molecular sieve can be changed.(2)Compared with the modified nanoscale Mo/HZSM-5 catalyst,the benzene yield of the methane non-oxidative aromatization reaction of the micron-sized Mo/HZSM-5 catalyst treated with the same concentration of the modified solution is the highest.(3)The 0.3 mol/L ammonia-modified micron Mo/HZSM-5 catalyst had the highest methane non-oxidative aromatization activity,and the target product benzene yield reached 14.3%.(4)Under different process conditions,the yield of benzene in the methane non-oxidative aromatization reaction of the 6 wt.% Mo/HZSM-5 catalyst on fixed bed was different.At the reaction temperature of 800 °C,reaction space velocity of 4800 m L/g/h,median particle size of 138 ?m,pre-carbonization temperature of 675°C,target product on Mo/HZSM-5 catalyst within 100 min.The largest production of benzene,achieve 8 mol/g.