Aromatization Of C₄ Hydrocarbons On The Parent And Modified IM-5 Zeolite

This paper mainly studied the aromatization reaction of C4 hydrocarbons on IM-5 and its modified zeolite which was prepared by alkali treatment, metal loading and Si loading, in addition, investigated effects of acidity and pore structure on the aromatization activity.Influences of alkali treatment on the aromatization of post-MTBE C4 was explorated. Results indicated that the alkali treatment can significantly improve the stability of aromatization reaction. With the help of Py-IR technology and the characterization of pore structure, it can be concluded that alkali treatment can reduce the amount of acid sites and increase the volume of pore. The best aromatization performance was achieved on the alkali-treated IM-5 zeolite modified by the following conditions: alkali solution concentration of 0.1mol/L; treated for 6h.Subsequently, influences of metal element loading and Si loading on iso-butane aromatization were studied, respectively. Results indicated that the introduction of Zn can improve the catalytic performance of IM-5 zeolite on iso-butane aromatization, and Cr-Zn system was better than Zn system, the best performance was obtained under the following conditions: Cr:Zn=1:2, the total loading content of 1.0wt%. Besides, the work made some survey on the recovery of Zn-HIM5, the best recovery condition turns to be:2h at 550℃. Lastly, the introduction of Si can increase the stability of reaction and the BTX selectivity, the best mode of loading was as follows:temperature of 50℃, SiO2 loading as 4.0wt%. Moreover, the result of characterization indicated that the import of Si can not only impair the acidity but shrink the pore, and this can be favorable for the aromatization reaction.