A method of making a xylene isomerization catalyst comprises the steps of (i) contacting a ZSM-5 zeolite starting material having a silica to alumina molar ratio of 20 to 50 and having a mesopore surface area in the range of 50 m.sup.2/gram to 200 m.sup.2/gram in a reactor with a base to provide an intermediate zeolite material; (ii) recovering the intermediate ZSM-5 zeolite material of step (i); (iii) contacting the intermediate zeolite material with an acid to provide an acid treated ZSM-5 zeolite product; (iv) recovering the acid treated ZSM-5 zeolite material; and (v) calcining the acid treated ZSM-5 zeolite material to provide a desilicated ZSM-5 zeolite product having a silica to alumina molar ratio of 20 to 150 and having a mesopore surface area in the range of 100 m.sup.2/gram to 400 m.sup.2/gram.

A process and catalyst system is disclosed for producing para-xylene from a C.sub.8 hydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The process modifies the conventional process by operating with a higher weight hourly space velocity, lower pressure and lower hydrogen partial pressure, which allows production of on-specification benzene product without penalty with respect to ethylbenzene conversion, para-xylene approach to equilibrium or xylene losses. The catalyst system comprises a first catalyst bed comprising a first zeolite having a constraint index from 1 to 12 and an average crystal size from 0.1 to 1 micron and a platinum hydrogenation component, and a second catalyst bed comprising a second zeolite having a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron and a rhenium hydrogenation component.

A process and catalyst system is disclosed for producing para-xylene from a C.sub.8 hydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The process modifies the conventional process by operating with a higher weight hourly space velocity, lower pressure and lower hydrogen partial pressure, which allows production of on-specification benzene product without penalty with respect to ethylbenzene conversion, para-xylene approach to equilibrium or xylene losses. The catalyst system comprises a first catalyst bed comprising a first zeolite having a constraint index from 1 to 12 and an average crystal size from 0.1 to 1 micron and a platinum hydrogenation component, and a second catalyst bed comprising a second zeolite having a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron and a rhenium hydrogenation component.

This invention relates to a method for dehydration of alcohols into olefins comprising an improved step for recovery of unreacted alcohol.

This invention relates to a method for dehydration of alcohols into olefins comprising an improved step for recovery of unreacted alcohol.

A method for preparing polybutene includes the steps of: supplying a C4 mixture to an isomerization reactor in which (i) 1-butene is isomerized into 2-butene by a hydrogen isomerization reaction using an isomerization catalyst in an isomerization zone of the isomerization reactor and (ii) iso-butene and 2-butene are separated by fractional distillation in a fractional distillation zone; supplying a C4 mixture containing 2-butene which is separated in the isomerization reactor to a skeletal isomerization reactor, in which a part of normal-butene is skeletal isomerized into iso-butene by a skeletal isomerization reaction using a skeletal isomerization catalyst, and the obtained skeletal isomerization mixture is supplied and recycled to the isomerization reactor; and supplying (i) a raw material containing the iso-butene of high concentration and which is separated from the isomerization reactor and (ii) a polymerization catalyst to a polybutene polymerization reactor and thereby producing polybutene by a polymerization reaction.

The present invention relates to heavy desorbent and light desorbent aromatics complex flow scheme. More particularly, this invention relates to the integration of a dual raffinate para-xylene separation process with two isomerization zones. The first isomerization zone is a liquid phase isomerization zone and the second isomerization zone is either an ethylbenzene isomerization zone, or an isomerization zone using MAPSO-31.

The present invention relates to heavy desorbent and light desorbent aromatics complex flow scheme. More particularly, this invention relates to the integration of a dual raffinate para-xylene separation process with two isomerization zones. The first isomerization zone is a liquid phase isomerization zone and the second isomerization zone is either an ethylbenzene isomerization zone, or an isomerization zone using MAPSO-31.

A process for the production of para-xylene is presented. The process includes the isomerization of C8 aromatics to para-xylene utilizing a new catalyst. The new catalyst and designated as UZM-54 is represented by the empirical composition in the as synthesized and anhydrous basis expressed by the empirical formula of:
M.sub.m.sup.n+R.sub.1r1.sup.p.sub.1.sup.+R.sub.2r2.sup.p.sub.2.sup.+Al.sub.1-xE.sub.xSi.sub.yO.sub.z
where M is an alkali, alkaline earth, or rare earth metal such as sodium and/or potassium, R.sub.1 and R.sub.2 are organoammonium cation and E is a framework element such as gallium, iron, boron, or indium. UZM-54 are characterized by unique x-ray diffraction patterns, high meso surface area, low Si/Al ratios.

The present disclosure is directed to a high-silica form of zeolite SSZ-32x, its synthesis in fluoride media using dipropylamine as a structure directing agent, and its use in catalytic processes.