Forming And Modification Of ZSM-5 Zeolite Study On Catalytic Performance

In this paper,the optimum temperature of ZSM-5 zeolite for methanol to olefins and the alkylation of toluene with methanol and the catalytic performance of ZSM-5 with different Si/Al2 ratios were investigated.In addition,four kinds of calcination methods were used to remove the template from ZSM-5 zeolite,and the effect of calcination method on the catalytic performance of ZSM-5 zeolite was studied.In the end,in view of the problems of the powder ZSM-5 zeolite,the spherical ZSM-5 zeolite was prepared and the influence of the calcining mode on the catalytic properties of the spherical ZSM-5 zeolite was studied.The modification of Mg element with mass fraction of 3%was used to study the modification of the powder first,then spherical and first spherical,then spherical modification the effect of two modified forms on the catalytic results.First,the template was calcined at 550? in the ordinary muffle furnace with the ratio of silicon and aluminum to 80,and the MTO reaction was carried out at different temperatures.The optimum temperature of the MTO reaction was 450 ?.6 kinds of Si/Al2 ratios powder ZSM-5 zeolite were calcined at 550 ? in ordinary muffle furnace and MTO reaction was performed at 450 ?.The selectivity of total low carbon olefins was 62.31%in the MTO reaction of Si/Al2 is 80,of which ethylene was 24.01%and propylene was 32.39%.The ratio of silica to aluminum and the spherical ZSM-5 zeolite after forming are used in four kinds of calcination methods and used in MTO reaction.The catalyst of microwave muffle furnace has the best effect,and the powder selectivity of low carbon olefin is 69.59%,of which ethylene is 27.35%,propylene is 35.71%,and the spherical total low carbon olefin is selective to 74.44%.Medium ethylene 34.55%,propylene 35.71%.Secondly,the alkylation of toluene methanol was studied,and the optimum reaction temperature was 520 ?,for the powder of Si/Al2 ratio is 80,the conversion of toluene was 40.65%,the conversion rate of methanol was 100%and the selectivity of p-xylene was 24.41%after the ordinary muffle furnace was roasted.After different roasting methods,the conversion rate of toluene is 45%,the conversion of methanol is 100%,and the selectivity of p-xylene is 28.40%.The ZSM-5 of the powders was spheric.After microwave roasting,the conversion of toluene was 55.63%,the conversion of methanol was 100%,and the selectivity of p-xylene was 44.39%.Finally,the modification of metal Mg with 80 spherical ZSM-5 zeolite showed that the effect of first modification was better.In the reaction of MTO,the selectivity of total low carbon olefin was 79.07%,of which ethylene 25.91%and propylene were 50.16%.In the alkylation of toluene with methanol,the conversion of toluene is 43.87%,the conversion of methanol is 100%,and the selectivity of p-xylene is 57.42%.