Abstract: A molecular sieve used in a process for separating olefinic hydrocarbons from paraffinic hydrocarbons is regenerated in a method which removes diolefins and aromatic hydrocarbons from the molecular sieve. The method comprises contacting the sieve with alkaline water and then drying the sieve with stream of a superheated light paraffin. The molecular sieve may be present in either a guard bed used upstream of a main separation zone or as part of the main adsorptive separation zone.

Abstract: A molecular sieve guard bed used in an adsorptive process for separating olefinic hydrocarbons from paraffinic hydrocarbons is regenerated in a method which recovers valuable hydrocarbons from the guard bed void volumes. The method comprises first contacting the sieve with a purge stream, with the initial effluent of the guard bed passed into a raffinate column to recover the olefinic hydrocarbons in the void volume of the bed. The flow of the effluent of the guard bed is then switched to a different fractionation column.

Abstract: A process for preparing benzene containing less than 1 ppm (wt) dioxane from an aromatic stream containing benzene which is contaminated with dioxane, the process including providing an aromatic stream containing benzene which is contaminated with dioxane; subjecting the aromatic stream to liquid phase adsorption by contacting an adsorbent contained in at least one column, which adsorbent comprises at least one substance selected from the group consisting of molecular sieves and clay; and recovering benzene containing less than 1 ppm (wt) dioxane. Preferably, the liquid phase adsorption is carried out at a pressure ranging from atmospheric pressure to 20 kg/cm.sup.2 and at a temperature ranging from ambient temperature to 50.degree. C. Preferably, the molecular sieves have a pore size of 10 .ANG.. The process may further include regenerating the adsorbent by passing a flow of nitrogen gas through the adsorbent at a temperature ranging from 200 to 300.degree. C.

Abstract: A process for separating para-xylene from a C.sub.8 feed in a simulated moving bed comprises a step for adsorption on a zeolite and desorption using a desorbent delivering an extract and a raffinate, and an extract crystallization step. A stream of water is introduced into the feed, into the desorbent and/or into the stream for recycling one flux in the column, such that the weighted average of the amounts of water measured in the extract and in the raffinate is in the range 1 to 200 ppm. The ratio S/F of the desorbent flow rate to that of the feed during the adsorption and desorption step is in the range 0.6 to 2.5.

Abstract: The capacity of a simulated moving bed adsorptive separation process is increased by flushing the contents of the transfer line just previously used to remove the raffinate stream from the adsorbent chamber back into the adsorbent chamber. This step is performed immediately upstream of the point of raffinate withdrawal. Preferably the feed stream to the process is used as the flushing liquid. This flush step eliminates the passage of a quantity of the raffinate material into the adsorbent chamber when the process conduit is subsequently used to charge the feed stream to the adsorbent chamber.

Abstract: A process for the management of polynuclear aromatic compounds produced in a hydrocarbon dehydrogenation zone wherein the effluent from the hydrocarbon dehydrogenation zone is contacted with an adsorbent to reduce the concentration of polynuclear aromatic compounds. The resulting dehydrogenated hydrocarbon having a reduced concentration of polynuclear aromatic compounds is reacted with methanol to produce an ether. A portion of the ether is contacted with a spent bed of adsorbent to recover at least a portion of the polynuclear aromatic compounds adsorbed thereon to thereby regenerate the adsorbent.

Abstract: A process for the management of polynuclear aromatic compounds produced in a hydrocarbon dehydrogenation zone wherein the effluent from the hydrocarbon dehydrogenation zone containing dehydrogenated hydrocarbons, dehydrogenatable hydrocarbons and trace quantities of mononuclear and polynuclear aromatic hydrocarbons is admixed with a recycle stream containing mononuclear aromatic compounds and the resulting admixture is contacted with an adsorbent to reduce the concentration of mononuclear and polynuclear aromatic compounds and to produce a stream comprising dehydrogenated hydrocarbons and dehydrogenatable hydrocarbons. An off-line spent adsorbent containing mononuclear and polynuclear aromatic compounds is contacted with a hot hydrogen-rich gas to recover at least a portion of said mononuclear and polynuclear aromatic compounds to thereby regenerate the spent adsorbent.

Abstract: Distillate or hydrotreated distillate effluent is separated into an aromatics rich permeate and an aromatics lean retentate by use of a permselective membrane with the aromatic rich permeate being sent to a hydrotreater, thereby increasing the quantity of reduced aromatics content product.

Abstract: An integrated process for the production of normal paraffins from a feed mixture of normal paraffins, iso-paraffins and aromatics is disclosed. The process integrates a normal paraffin sorption process and an aromatics sorption process. The normal paraffin product of the process of our invention meets the commercial requirements for production of detergents, including sufficiently-low concentrations of both iso-paraffins and aromatics. The process achieves these results without the need for two additional factionation columns that are necessary to prior unintegrated processes.

Abstract: A totally contained adsorption process for the substantial total removal and conversion of benzene to cyclohexane in gasoline boiling range streams. At least a portion of the gasoline boiling range stream is passed through an adsorption zone containing an adsorbent which will selectively adsorb benzene from the stream. The process is totally contained in the sense that substantially total conversion of benzene to cyclohexane is achieved without the need for added desorbent. The desorbent is cyclohexane which is generated in the process.

Abstract: A process for purifying linear paraffins in which a hydrocarbon stream containing linear paraffins contaminated with aromatics, sulfur-, nitrogen-, and oxygen-containing compounds, and color bodies, but essentially free of olefins, is contacted with a zeolitic solid adsorbent such as a NaX zeolite or zeolite MgY. After adsorption the zeolitic solid adsorbent is desorbed with an alkyl-substituted aromatic desorbent such as toluene.

Abstract: A method for the separation of benzene from a hydrocarbon stream, such as a gasoline boiling range stream, which comprises contacting the hydrocarbon stream with an adsorbent capable of selectively adsorbing the benzene from the stream, hydrogenating the adsorbed benzene to cyclohexane, and desorbing the cyclohexane from the adsorbent. The hydrogenation of the benzene to cyclohexane facilitates the removal of the benzene from the adsorbent.

Abstract: A method for selectively separating benzene from gasoline boiling range streams by first fractionating the stream to produce a C.sub.6 heartcut fraction which is then passed to an adsorption zone comprised of a bed of solid adsorbent material capable of selectively removing benzene from the stream. The absorbent is regenerated with a suitable desorbent, preferably toluene.

Abstract: A method for selectively separating benzene from gasoline boiling range streams by first passing the stream to an adsorption zone comprised of an adsorbent capable of selectively adsorbing benzene from the stream. A substantially benzene-free stream results and the adsorbent is regenerated by treating it with a desorbent solvent capable of desorbing benzene from the solid adsorbent.

Abstract: A process for purifying linear paraffins in which a hydrocarbon feedstream containing linear paraffins contaminated with aromatics, sulfur-, nitrogen-, and oxygen-containing compounds, and color bodies, and also containing up to about 5 wt % desorbent from effluent recycle, is contacted with a solid adsorbent such as a NaX zeolite or zeolite MgY; after adsorption the adsorbent is desorbed with an alkyl-substituted aromatic desorbent, such as toluene. As the adsorent bed is being desorbed, the initial effluent from the adsorption cycle will contain levels of desorbent and may be recycled to the hydrocarbon feedstream. Previous to the removal of impurities from the adsorbent by desorption, the desorbent displaces interstitial linear paraffins which are also recycled to the hydrocarbon feedstream.

Abstract: A process for purifying linear paraffins in which a hydrocarbon stream containing linear paraffins contaminated with aromatics, sulfur-, nitrogen-, and oxygen-containing compounds, and color bodies, but essentially free of olefins, is contacted with a solid absorbent such as a NaX zeolite or zeolite MgY. After adsorption the adsorbent is desorbed with an alkyl- substituted aromatic desorbent, such as tuluene. The initial effluent from the adsorb cycle, which will contain a high concentration of residual desorbent, is recycled to a desorbent recovery system. The level of desorbent in the adsorber effluent is monitored on a real time basis until the desorbent level of the adsorber effluent declines from a plateau level, i.e., a 100% plateau level, that correlates with the level of impurities, particularly the aromatic impurities in the feed, which is an indication of aromatics breakthrough, thereby signaling the need to switch the adsorbent beds.

Abstract: Aromatic hydrocarbons are readily recovered from aqueous solutions by contacting the aqueous solution with an oxidized activated carbon having a low concentration of acidic oxides.The novel oxidized activated carbon is produced by contacting activated carbon with an acidic oxidizing agent which is used in low concentrations.The process can be employed to reduce aromatic hydrocarbons such as benzene from aqueous solutions such as industrial effluents or potable water supplies to levels permissible by environmental protection regulations.

Abstract: A process for enriching the fraction of 2,6-diisopropylnaphthalene contained in a quantity of mixed dialkylated naphthalenes. The mixed dialkylated naphthalenes are contacted with an adsorbant bed containing one or more molecular sieves which demonstrate shape selective preference for the 2,6-diisopropylnaphthalene isomer over other dialkylated naphthalenes. The adsorbant bed is then contacted with a desorbant capable of desorbing the 2,6-diisopropylnaphthalene from the pores of the adsorbant.

Abstract: A process for the separation of 2,7 DIPN from a hydrocarbon feed mixture comprising 2,7 DIPN and one or more other DIPN isomers, which process employs an adsorbent, comprising a type Y zeolite, dried to an LOI less than 10% which has been at least partially cation exchanged, at exchangeable sites, with potassium. The 2,7 DIPN thereafter is removed from the adsorbent by contacting it with an aromatic hydrocarbon desorbent material, comprising a xylene, e.g., para-xylene, benzene or toluene at desorbent conditions, and is recovered as an extract product stream. In a preferred embodiment, the process uses a simulated moving-bed countercurrent flow system.

Abstract: The chromatographic adsorption separation of coumarone from indene-containing coal tar distillate feed mixtures with an alkali metal (Group IA) exchanged X-zeolite and polar materials, e.g., ketones, alcohols or esters as desorbents. Also disclosed is a process for separating a coumarone-indene coextract with sodium-exchanged Y zeolite and toluene as desorbent.

Abstract: A high flash point cycloolefin composition, including at least 50% by weight dicyclopentadiene, the composition having a flash point of greater than 100.degree. F. and a viscosity of from about 3 cps to about 3000 cps at about 70.degree. F. and about 1 atmosphere pressure. The cycloolefin composition is used in a method of preparation of cycloolefin for polymerization by metathesis catalysis to form a substantially crosslinked thermoset polymer by: distilling the cycloolefin to form distilled cycloolefin, and contacting the distilled cycloolefin and an adsorbent.

Abstract: A novel polymer product comprised of polymerized units of dicyclopentadiene and method of making the same as disclosed.

Abstract: A high flash point cycloolefin composition, including at least 50% by weight dicyclopentadiene, the composition having a flash point of greater than 100.degree. F. and a viscosity of from about 3 cps to about 3000 cps at about 70.degree. F. and about 1 atmosphere pressure. The cycloolefin composition is used in a method of preparation of cycloolefin for polymerization by metathesis catalysis to form a substantially crosslinked thermoset polymer by: distilling the cycloolefin to form distilled cycloolefin, and contacting the distilled cycloolefin and an adsorbant.

Abstract: Aromatic hydrocarbon impurities are removed from a liquid paraffin containing the same by contacting the liquid paraffin in the liquid phase at relatively low temperatures with an X-type zeolite molecular sieve material. The contacting is performed without recycle and purified liquid paraffin containing less than about 0.01% by weight aromatics is obtained.

Abstract: A method and apparatus for the semi-continuous batch separation of a feed mixture of gaseous products into individual substantially pure products utilizes preferential adsorption in which all the components of a gaseous feed mixture are adsorbed by one or more adsorbers through which the feed mixture of gaseous products are sequentially cycled through the steps of (1) progressive adsorption of adsorbates from the mixture of gaseous products; (2) rectification of the adsorbates and (3) desorption of adsorbates contained in the adsorber with the adsorber being readied for further adsorption. Substantially pure gases are collected at appropriate intervals throughout the sequential cycling.

Abstract: A process for separating a normal paraffin hydrocarbon from a mixture of the same with a cyclic and/or branched chain paraffin hydrocarbon. The process comprises contacting the mixture at a temperature of from about 120.degree. C. to about 140.degree. C. with a zeolite free molecular sieve comprising silicalite. The normal paraffin hydrocarbon is selectively retained and will preferably be recovered from the molecular sieve by displacement with a displacement material.

Abstract: A process for reducing the level of cyclopentadiene present in a hydrocarbon stream containing isoprene and cyclopentadiene which involves contacting the stream with a base wherein said base is selected from the group consisting of potassium hydroxide, sodium hydroxide and potassium fluoride. The base is situated on activated carbon carrier.

Abstract: Solvents which may be used as mediums for the polymerization of olefinic hydrocarbons to form polymers useful as membranes in a gas separation process require purification to remove any impurities which will effect the aforesaid polymerization. Purification of these solvents such as cyclohexane may be effected by treating the solvent with titanium tetrachloride, contacting the solution with an adsorbent such as silica gel and thereafter distilling the solvent in the presence of a purification agent such as an alkaline metal aluminum hydride or borohydride.

Abstract: Novel solid salt compositions are described containing, for example, tetraaryl- and triarylaralkyl-phosphonium and arsonium cations and tetraaryl- and tetraaryloxy-boranates and aluminates and polyanionic metal oxide surfaces, for example, as anions. The salts are useful for extracting aromatics and olefins from paraffinic hydrocarbon and aqueous liquid feedstreams, and from vapor and gas feedstreams by absorption.

Abstract: A process for separating a normal paraffin from a mixture of the same with another structural class of hydrocarbon selected from the cyclic hydrocarbons having greater than six carbons per molecule and the branched chain hydrocarbons. The process comprises contacting the mixture at adsorption conditions with an adsorbent comprising silicalite. The normal paraffin is selectively adsorbed and will preferably be recovered from the adsorbent by desorption with a desorbent material.

Abstract: Cyclohexene can be advantageously separated from a mixture containing as main components benzene, cyclohexene and cyclohexane by a process wherein said mixture is brought into contact with a type X aluminosilicate zeolite, which has been ion-exchanged with a silver ion, as an adsorbent, whereby cyclohexene is selectively adsorbed thereon, and then, cyclohexene is desorbed therefrom. The desorption of cyclohexene is preferably carried out by using a desorbent, such as an alkylbenzene having 7 or 8 carbon atoms in the molecule.

Abstract: Compounds of formula I are useful in the separation of a gas such as oxygen, hydrogen, sulphur dioxide, alkenes and carbon monoxide from a fluid comprising the gas.Mn.sup.11 LX.sub.2 IIn formula I: L represents a monodentate ligand of formula IA and X is a species capable of existing as an anionPR.sup.1 R.sup.2 R.sup.3 IAwherein R.sup.1, R.sup.2 and R.sup.3 which may be identical or different represent substituted or unsubstituted alkyl, cycloalkyl or aryl groups or hydrogen and X represents --Cl, --Br, --I, --CN, --NO.sub.2, --NO.sub.3, --OH, --NCS or --NCO, provided that no more than two of the groups R.sup.1 R.sup.2 and R.sup.3 are substituted or unsubstituted aryl groups and that at least one of the groups R.sup.1, R.sup.2 and R.sup.3 is a substituted or unsubstituted alkyl, cycloalkyl or aryl group.

Abstract: In the separation of cyclohexene from a feed which contains cyclohexene and cyclohexane, the feed is contacted with a type X and/or type Y aluminosilicate zeolite, thereby adsorbing cyclohexene selectively on the zeolite, and then the zeolite which adsorbed cyclohexene is contacted with a trimethylbenzene to desorb cyclohexene.