Abstract: An adsorptive separation process is disclosed for separating para-aromatic isomers from a hydrocarbon feed containing a mixture of aromatic isomers, using a crystalline aluminosilicate adsorbent which has been treated with an alkyl amine preferably an alkyl amine hydrochloride. The alkyl amine treatment substantially increases the selectivity of the adsorbent for the para-xylene isomer, relative to the heavy desorbent p-DEB, thereby improving the efficiency of the separation process.

Abstract: An adsorptive separation process for separating ethylbenzene from a feed mixture comprising ethylbenzene and a plurality of xylene isomers, which process comprises contacting the feed mixture with an adsorbent comprising strontium exchanged type X or type Y zeolite, selectively adsorbing substantially all of the said xylene isomers to the substantial exclusion of the ethylbenzene and thereafter recovering high-purity ethylbenzene. A desorption step may be used to desorb the adsorbed xylene isomers. The process can be either in the liquid or vapor phase.

Abstract: An adsorptive separation process for separating ethylbenzene from a feed mixture comprising ethylbenzene and a plurality of xylene isomers which process comprises contacting the feed mixture with an adsorbent comprising strontium and potassium exchanged type X or type Y zeolite, selectively adsorbing substantially all of the said xylene isomers to the substantial exclusion of the ethylbenzene and thereafter recovering high-purity ethylbenzene. A desorption step may be used to desorb the adsorbed xylene isomers. The process can be either in the liquid or vapor phase.

Abstract: A method for the production of an adsorbent, having increased capacity for olefins and decreased catalytic activity for polymerization and isomerization, useful in the separation of olefins from a hydrocarbon mixture comprising olefins and paraffins. The methods basically comprises contacting a precursor mass comprising sodium X or sodium Y zeolite and amorphous material selected from the group consisting of silica, alumina and silica-alumina mixtures and compounds as a binder with an aqueous sodium hydroxide solution to increase the sodium cation content of the zeolite and to remove a small portion of silica and alumina; washing the zeolite with water to remove excess caustic solution; and, drying the zeolite to reduce the volatile content.

Abstract: An improved process for the separation of olefins from a hydrocarbon feed mixture comprising olefins and saturates which process uses an adsorbent comprising sodium type X or sodium type Y zeolite to selectively adsorb the olefins. The improvement comprises employing an adsorbent produced by the steps of: contacting a precursor mass comprising type X or type Y zeolite having a Na.sub.2 O/Al.sub.2 O.sub.3 ratio less than about 0.7 with an aqueous sodium hydroxide solution at ion exchange conditions to effect the addition of sodium cations to the mass and the removal of a small amount of silica and alumina, washing the mass with water to remove excess sodium hydroxide solution; and, at least partially dehydrating the mass at dehydrating conditions thereby producing an adsorbent which has both increased capacity for olefins and decreased catalytic activity.

Abstract: An adsorptive separation process for separating ethylbenzene from a feed mixture comprising ethylbenzene and a plurality of xylene isomers, which process comprises contacting the feed mixture with an adsorbent comprising strontium exchanged type X or type Y zeolite, selectively adsorbing substantially all of the said xylene isomers to the substantial exclusion of the ethylbenzene and thereafter recovering high-purity ethylbenzene. A desorption step may be used to desorb the adsorbed xylene isomers. The process can be either in the liquid or vapor phase.

Abstract: An adsorptive separation process for separating ethylbenzene from a feed mixture comprising ethylbenzene and a plurality of xylene isomers which process comprises contacting the feed mixture with an adsorbent comprising strontium and potassium exchanged type X or type Y zeolite, selectively adsorbing substantially all of the said xylene isomers to the substantial exclusion of the ethylbenzene and thereafter recovering high-purity ethylbenzene. A desorption step may be used to desorb the adsorbed xylene isomers. The process can be either in the liquid or vapor phase.

Abstract: An improved process for the separation of a para-cresol from a feed mixture containing para-cresol and at least one other cresol isomer which process employs a crystalline aluminosilicate adsorbent to selectively adsorb para-cresol from the feed mixture. The improvement basically comprises employing a desorbent material comprising an alcohol to increase the selectivity of the adsorbent for para-cresol thereby allowing a more efficient separation with a higher purity extract stream recovered from the process.

Abstract: A method of manufacturing an adsorbent comprising X or Y zeolite containing one or more selected cations at the exchangeable cationic sites. The method basically comprises the steps of: contacting a base material comprisng X or Y zeolite with an aqueous sodium hydroxide solution at first ion exchange conditions to effect the addition of sodium cations to said base material; treating the sodium-exchanged base material at second ion exchange conditions to effect the essentially complete exchange of sodium cations with one or more cations selected from the group consisting of Group IA, Group IIA, and Group IB of the Periodic Table of Elements; and, drying the material at conditions to reduce the LOI at 900.degree. C. to less than about 10 wt. %. The adsorbent produced by the method exhibits faster adsorption-desorption rates for a desired extract component than does an adsorbent not produced by the method.

Abstract: An improved process for the separation of olefins from a hydrocarbon feed mixture comprising olefins and saturates which process uses a zeolite adsorbent to selectively adsorb the olefins. The improvement comprises employing a zeolite adsorbent produced by the steps of: contacting a precursor mass containing type X structured zeolite and amorphous material as a binder with an aqueous caustic solution to effect the addition of alkali metal cations to the crystalline structure; washing the mass with water to remove therefrom excess caustic solution; and, at least partially dehydrating said mass at dehydrating conditions thereby producing an adsorbent which has both increased capacity for olefins and decreased catalytic activity.

Abstract: A solid adsorbent useful for the separation of para-xylene from a mixture of C.sub.8 aromatic hydrocarbons. The adsorbent is prepared by the steps of: ion-exchanging a precursor mass containing type X or type Y zeolite and amorphous material with an aqueous sodium hydroxide solution to effect the addition of sodium cations to the zeolite structure, ionexchanging the sodium-exchanged mass to effect the essentially complete exchange of sodium cations, and drying the resulting material at conditions to reduce the LOI at 900.degree. C. to less than about 10 wt. %. The sodium cations can be essentially completely exchanged with barium and potassium cations in a weight ratio of from about 1.5 to 200 or with barium alone. I have found that the sodium hydroxide exchange step produces an adsorbent that has faster adsorption-desorption rates for the desired para-xylene isomer and permits a suitable adsorbent to be produced which contains barium cations alone.

Abstract: A process for the separation of the para-isomer from a hydrocarbon feed mixture comprising at least two bi-alkyl substituted monocyclic aromatic isomers, including the para-isomer, said isomers having from 8 to about 18 carbon atoms per molecule using a specially prepared adsorbent comprising a Y zeolite containing at the exchangeable cationic sites one or more selected cations. The feed mixture is passed through a bed of the adsorbent wherein the para-isomer is preferentially adsorbed within the adsorbent and thereafter recovered from the adsorbent. Novel feature of the process is the use of the specially prepared adsorbents which have faster adsorption-desorption rates for the desired para-isomer.

Abstract: A process for separating the para-isomer from a feed mixture containing at least two bi-alkyl substituted monocyclis aromatic isomers, including the para isomer, said isomers having from 8 to about 18 carbon atoms per molecule which process comprises contacting said mixture with an adsorbent prepared by the steps of: contacting a base material comprising type X or type Y zeolite with a fluoride-containing aqueous sodium hydroxide solution at first ion exchange conditions to effect the addition of sodium to and the extraction of alumina from said base material; treating the sodium-exchanged base material at second ion exchange conditions to effect the essentially complete exchange of sodium cations; and, drying the material at conditions to reduce the LOI at 900.degree. C. to less than about 10 wt. % thereby selectively adsorbing at adsorption conditions said para isomer.

Abstract: An adsorptive separation process for separating ethylbenzene from a feed mixture comprising ethylbenzene and at least one xylene isomer, which process comprises contacting the feed mixture with a crystalline aluminosilicate adsorbent comprising type X structured zeolite containing at the exchangeable cationic sites at least one cation selected from the group consisting of cations of elements of Group I-A of the Periodic Table of Elements to effect the selective adsorption of ethylbenzene. The ethylbenzene adsorbed by the adsorbent is thereafter recovered as a purified product. The process can be either in the liquid or vapor phase.