Study On The Methylation Of Methylnaphthalene And Alcohal Over Modified β Zeolite Catalysts

The methylation of methylnaphthalene with methanol to synthesis 2,6-DMN over modified zeolites H has been investigated in a fixed bed reactor.The modify mthods such as ion exchange, infuse and chemical liquid-phase deposition have been imposed in the modifying of zeolites H 13 .The porestructure and acid properties of modified catalysts have been characterizedby BET, XRD, NH3-TPD, IR and TG techniques. In the end the reactionability of modified catalysts have been studied all.The reaction conditions of methylnaphthalene with methanol has been discussed on zeolites H . The results showed that: the WHSV of MN was the main factor effecting the reaction and the next factor was reaction temperature, the material proportion was the least factor effecting the reaction. The best reaction temperature was 460 C, the smaller was the WHSV of MN, the higher was the conversion of MN and selectivity of 2,6-DMN.The reagents such as magnesium nitrate, zinc nitrate, cobalt nitrate, cerium nitrate have been used in the ion exchanging of zeolites H and the effect of exchange amount of ions on the surface area, acid site strength and melhylation reaction of the modified catalysts have been studied.The reagents such as magnesium nitrate, boracic acid, phosphate , copper nitrate have been used in the infusing of zeolites H and the surface area,acid site strength and methylation reaction of the modified catalysts have been charactered.The reagents positive silicic acid second ester has been utilized in the chemical liquid-phase deposition of zeolites H .The effect of depositing consistence , depositing time and the ratio of zeolites H to solvent on the physics- chemical property and reaction ability of catalysts have been discussed .Then the regeneration of catalysts modified by ion exchange and infusing has been studied by TG analysis. It was founded that the coke rate was decreased. It showed that the modified methods such as ion exchange and infuse could moderately slow the coking speed of catalysts.The innovations of this dissertation lie in the solid acid zeolites H 3 is environment amity catalysts and the fixed bed reactor is favor of industrialization.Chemical liquid-phase deposition is a new type modified method.In this dissertation some valuable methods in the fields such as the modifying of catalysts and charactering of catalysts have been afforded. All these will be propitious to the modifying of catalysts and the study of mechanism of the synthesis of 2,6-DMN.