Influence Of ? Zeolite With Adding Different Additives(MTS And PVP) And Its Catalytic Performance Of Cumene

Beta zeolite as a catalyst has been widely used in the field of petroleum refining and processing process,because of its unique channel structure,rich specific surface area,high silicon aluminium ratio and the strong acid.But as of yet Beta zeolite average particle size of industrial production is larger,reunion phenomenon seriously,leading to lots of problems such as the transfer resistance increases in the pore about catalytic molecules,carbon deposition,catalyst deactivation and low utilization rate of raw materials.In this paper,to achieve the effect of the particle size can be controlled,through adding two different additives,via the crystal nucleus protection method to synthesis Beta zeolite with adding MTS as the reagent,it can be inhibited the growth of the crystal nucleus;Although the modification effect is excellent,silane coupling agent(SCA)cost is too much,and the process of synthesis SCA is complex,SCA is not fit to become additive of modified Beta zeolite to be used in large-scale industrialization.And it also better performance of Beta zeolite than traditional by synthesized with polyvinylpyrrolidone(PVP)as another addtive.This thesis is mainly studied different additives on the structure and properties of Beta zeolite,the main results are as follow:1.Beta zeolite was successfully synthesized via crystal nucleus protection to decrease the size of crystal by adding methyltriethoxysilane(MTS).Some factors of obtained Beta zeolite are investigated in detail in the synthesis system,different crystallization temperature,crystallization time,different adding amount of MTS and of the molecular sieve The results indicated that the Beta zeolite with the high acid content and Si/Al(25.76)were successfully synthesized at crystallization temperature of 140?for 120 hours,when adding amount of MTS was 0.5 mL,2 mL of ammonia content,which had the average particle size about 240 nm,the BET surface area of 657m~2/g.Meanwhile,the best catalytic performance could achieve as high as 84.1%at the beginning of the reaction and maintain 43.0%even after the reaction time of 400 min.2.Beta zeolite was successfully synthesized by adding polymer PVP(K30)as another addtive.The effect of Beta zeolite structure and performanc with adding different amount of PVP was studied details.Results show that the addition of PVP can shorten the Beta zeolite nucleation stage,thus greatly shorten the crystallization time required for the zeolite,and the crystallinity of the products are higher than the traditional zeolite,obtained the high specific surface area(663-772 m~2/g),high Si/Al ratio(25.68 26.86),high acidity.When adding amount of PVP was 1.5 g,to acquire the catalytic performance,the initial conversion rate reached 78.87%,still retains 26.18%even after the reaction time of 400 min.3.Based on the above 2,The effect of Beta zeolite structure and performanc with adding different molecular weight of PVP(K15,K90)was studied details.the main conclusion are as follow:every kind of molecular weight of PVP have no effect on the Beta zeolite morphology,but all of them can increases crystallinity of Beta zeolite,with the increase of molecular weight of PVP,the sample of crystallinity show a trend that increased at first and then decreased and the same trend about sample's specific surface area.The catalysts about are synthesized by K15 and K90 showd slower deactivation rate in catalytic reaction.