Non-hydrocracking Of Diesel To Produce More Gaosline

The mesopores were introduced into the ZSM-5 zeolites using the methods of acid-treated dealuminization and alkali-treated desiliconization.The suitable HZSM-5 zeolite catalysts for the diesel non-hydrocracking were constructed to produce more gasoline.The effects of the change in textural property and acidic property of the catalyst after dealuminization and desiliconization on the conversion,gasoline yield and product distribution during the non-hydrocracking reaction of diesel were investigated.The treated catalysts were characterized by XRD,TEM,NH3-TPD,N2 adsorption-desorption isotherm,FT-IR,TG-DTG,Py-IR and 27Al MAS NMR.The result shows that the efficiency of removing of framework aluminum and extra-framework aluminum using different types acid was different;the framework aluminum and extra-framework aluminum were removed simultaneously and some mesopores were introduced when the hydrochloric was used,so the Sext and the Vext increased;with the concentration of hydrochloric increased,the amount of LAS and BAS were reduced,but the ratio of LAS to BAS increased.The 1.0 mol/L hydrochloric exhibited the best cracking activity during the treatment of different concentrations,the YAG to be 28.77%.The hierarchical ZSM-5 zeolites were effectively prepared after the alkali-treated desiliconization,The Sext,Vext and the average pore diameter of the catalysts were increased obviously,and th e Smic shows opposite trend,resulting in more weak aicd sites and the Lewis acid sites,while the strong acid sites and the Br(?)onsted acid sites were both decreased,meanwhile the ratios of LAS to BAS were improved.After alkali treatment,HZ-0.5A exhibited the maximal conversion,yield and selectivity of gasoline to be 56.07%,34.63%,and 61.73%.