Preparation Of HY Zeolite Catalyst And Its Performance In Isobutane Alkylation

With the implementation of the National Sixth Standard for Automotive Gasoline,the content of olefins and aromatics has been strictly restricted.If ethanol gasoline is fully popularized in China,MTBE and other high-octane oxygenate additives will not be added,and gasoline pools need more high-octane blending components.Alkylated gasoline with low sulfur,low olefin,low benzene,high octane and other characteristics is a good gasoline blending component.At present,liquid acids are widely used as isobutane alkylation catalysts in industry,which pollute the environment and cause serious equipment corrosion.Solid acid alkylation has little pollution and no equipment corrosion problems.It is an environment-friendly technology with good development prospects.However,the solid acid alkylation catalyst has low activity and rapid deactivation,which is an urgent problem to be solved at present.In this thesis,the NaY zeolite is synthesized by hydrothermal method,and the purpose of improving the catalyst life is achieved by reducing the zeolite grain size,controlling the ratio of silicon to aluminum,and improving the hydrophilic and hydrophobicity of the catalyst surface.The alkylation performance of HY zeolite with Si/Al=5,Si/Al=12,Si/Al=25 was investigated.By choosing a suitable binder,the hydrophilic and hydrophobic properties of the catalyst surface are improved,and the purpose of reducing the occurrence of olefin polymerization is achieved.The alkylation performance of SB powder,lipophilic alumina,hydrophilic alumina and acidic alumina as binder molding catalysts was investigated.The results showed that the reaction effect of the catalyst formed with Si/Al=5 HY zeolite and lipophilic alumina as the binder was the best.Although the activity of HY zeolite catalyst is better,regeneration is difficult.In order to improve the catalyst regeneration efficiency,this paper adopts the method of metal hydrogenolysis to regenerate the deactivated catalyst.A series of catalysts were prepared by using nickel metal and metal molybdenum as active components for hydrogenation,and nickel,molybdenum,nickel and molybdenum oxide composite modification and nickel and molybdenum sulfide composite modification.The catalyst regeneration performance was evaluated in a laboratory-made fixed-bed reactor.The experimental results show that the catalyst with 5%-7.5%nickel modified zeolite and lipophilic alumina as the binder is the best,which can not only meet the requirements of regeneration performance,but also have better reaction performance.The single-pass catalyst life is greater than 20 h,the octane number of the resulting alkylated oil is greater than 95,and the carbon eight content is greater than 80%.The effects of raw material types and process conditions on the alkylation reaction were investigated.The experimental results show that when isobutane reacts with four butene isomers,the reaction effect of 1-butene and 2-butene is not much different However,the alkylated oil obtained by 2-butene has a higher octane number;when isobutene is used as the raw material,the catalyst has the longest life,but the selectivity is poor.The best process conditions are:temperature 50?-70?,alkene ratio(P/O)=110-140,butene weight hourly space velocity=0.05-0.07 h^-1.