Abstract: Akylation product is contacted with a purification medium in a liquid phase pre-reaction step to remove impurities and form a purified stream. The purified stream may then be further processed by liquid phase transalkylation to convert the polyalkylated aromatic compound to a monoalkylated aromatic compound. The process may use a large pore molecular sieve catalyst such as MCM-22 as the purification medium in the pre-reaction step because of its high reactivity for alkylation, strong retention of catalyst poisons and low reactivity for oligomerization under the pre-reactor conditions. Olefins, diolefins, styrene, oxygenated organic compounds, sulfur containing compounds, nitrogen containing compounds and oligomeric compounds are removed.

Abstract: A process is provided for the concentration and recovery of ethylene and heavier components from an oxygenate conversion process. A separation process such as a pressure swing adsorption (PSA) process is used to remove hydrogen and methane from a demethanizer overhead stream comprising hydrogen, methane, and C2 hydrocarbons and subsequently return the recovered C2 hydrocarbons to be admixed with the effluent from the oxygenate conversion process. This integration of a separation zone with a fractionation scheme in an ethylene recovery scheme using an initial demethanizer zone resulted in significant capital and operating cost savings by the elimination of cryogenic ethylene-based refrigeration from the overall recovery scheme.

Abstract: The invention concerns a process for eliminating arsenic from a hydrocarbon cut in which said cut is brought into contact with an absorption mass that is at least partially pre-sulphurized and comprises a support and lead oxide.

Abstract: Particulate sorbent compositions which are suitable for the removal of sulfur from streams of cracked-gasoline or diesel fuel are provided which have increased porosity, improved resistance to deactivation through the addition of a calcium compound selected from the group consisting of calcium sulfate, calcium silicate, calcium phosphate or calcium aluminate to the support system comprised of zinc oxide, silica and alumina having thereon a promotor wherein the promotor is metal, metal oxide or metal oxide precursor with the metal being selected from the group consisting of cobalt, nickel, iron, manganese, copper, molybdenum, tungsten, silver, tin and vanadium or mixtures thereof and wherein the valence of such promotor has been substantially reduced to 2 or less. Process for the preparation such sorbent systems as well s the use of same for the desulfurization of cracked-gasolines and diesel fuels are also provided.

Abstract: An adsorption process for the recovery of paraxylene from mixed xylenes using a molecular sieve adsorbent comprising SSZ-25, MCM-22, PSH-3, ERB-1, or ITQ-1. A preferred desorbent for the process is benzene. A hybrid adsorption/crystallization PX purification process is also described using the molecular sieve adsorbent.

Abstract: A method and apparatus for continuously reacting a feed gas to form a product and separating the product from unreacted feed gas is provided. The apparatus includes a plurality of compartments and means for connecting the compartments in a series, with the last compartment in the series being connected to the first compartment in the series to provide a closed loop. Each compartment may include an upstream reaction zone and a downstream separation zone.

Abstract: Monomethyl branched C10-C15 paraffins or olefins are recovered from a mixture comprising other nonnormal hydrocarbons such as di-isoparaffins, di-isoolefins and aromatics by adsorptive separation in a process which uses an adsorbent comprising silicalite and a desorbent comprising a C5 or C6 cycloparaffin. The recovered monomethyl hydrocarbons may then be used to form a monomethyl branched alkylaromatic hydrocarbon useful as a detergent precursor.

Abstract: The present invention is a process to remove a major portion of metals and coke precursors from a hydrocarbon stream. The steps of the process include contacting the feedstream with a hydrocarbon insoluble adsorbent, recovering the oil which does not adsorb and removing the metals and coke precursors from the adsorbent.

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: Monomethyl branched C10-C15 paraffins or olefins are recovered from a mixture comprising other nonnormal hydrocarbons such as di-isoparaffins, di-isoolefins, naphthenes and aromatics by adsorptive separation in a process which includes a prepulse step. In the prepulse step nonnormal hydrocarbons which are readily separated from the product is passed into the adsorbent bed immediately before or with the feed stream. This increases the selectivity of the system and allows for easier separation of the desired hydrocarbons. The recovered monomethyl hydrocarbons may then be used to form a monomethyl branched alkylaromatic hydrocarbon useful as a detergent precursor.

Abstract: A process for the purification of a fluid stream containing a sulphur contaminant, such as hydrogen sulphide, and mercury, phosphine, stibine, and/or arsenic compounds as a second contaminant wherein said fluid stream is passed through a bed of a particulate absorbent containing a sulphide of a variable valency metal, especially copper, that is more electropositive than mercury, to remove said second contaminant and then the sulphur contaminant is removed from at least part of the effluent from that bed by passing that part of the effluent through a bed of a particulate sulphur absorbent comprising a compound selected from oxides, hydroxides, carbonates and basic carbonates of said variable valency metal is disclosed. The removal of the sulphur contaminant converts said variable valency metal compound to the corresponding sulphide. The resulting bed of variable valency metal sulphide is subsequently used for the removal of the second contaminant.

Abstract: The invention provides specific adsorbents and methods for separating an unsaturated hydrocarbon from a mixture containing such hydrocarbon. The adsorbents and methods are useful for separating dienes from mono-olefins.

Abstract: A catalyst for removing olefins from aromatic compounds or mixtures of aromatic compounds wherein the catalyst is a naturally acidic smectite clay containing exchangeable cations wherein the naturally acidic smectite clay has a cation exchange capacity of 40 to 80 meq./100 g. and wherein the exchangeable cations include 5 to 70 meq./100 g. of Al.sup.3+ cations, a process for the preparation of this catalyst including treating a naturally acidic smectite clay with an aluminum salt solution wherein the salt solution includes Al.sup.3+ ions at a concentration of at least 10 meq./100 g. of the catalyst, and a process for the removal of olefins from aromatic compounds or mixtures of aromatic compounds using the above-described catalyst.

Abstract: For producing three effluents which are respectively rich in straight chain paraffins, in mono-branched paraffins, and in di-branched and tri-branched paraffins possibly with naphthenic and/or aromatic compounds, from C5-C8 cuts or intermediate cuts (C5-C7, C6-C8, C7-C8, C6-C7, C7 or C8), comprising paraffic and possibly naphthenic, aromatic and olefinic hydrocarbons, the separation process of the invention uses at least two separation units operating either by adsorption or by permeation. It is of particular application when coupled with a hydro-isomerization process, which selectively recycles straight chain and mono-branched paraffins, necessary with paraffins containing more than 7 carbon atoms.

Abstract: A process for separating meta-xylene from a mixture containing meta-xylene, para-xylene, and ortho-xylene has been developed. The process involves contacting the mixture with zeolite Beta to effect the adsorption of the para-xylene, ortho-xylene, and ethylbenzene in preference to the meta-xylene and recovering the meta-xylene.

Abstract: A catalyst is described on the basis of acid-activated smectitic clay minerals for removing olefins from aromatic compounds or mixtures of aromatic compounds which is characterized in that the acid-activated clay mineral contains at least 5 milli-equivalents/100 g of exchangeable Al.sup.3+ cations.

Abstract: The invention provides a method for purification of an .alpha.-olefin selected from ethylene and propylene for polymerization use which comprises contacting the .alpha.-olefin with an alkali metal carried on a support material. The invention further provides a method for production of a poly-.alpha.-olefin which comprises polymerizing the thus purified .alpha.-olefin in the presence of a polymerization catalyst comprising a transition metal catalyst component and an organometallic catalyst component.

Abstract: Processes using heterogeneous adsorbents are disclosed for purification of relatively impure unsaturated hydrocarbons such as olefins, which are typically produced by thermal cracking of suitable hydrocarbon feedstocks, by passing a feed stream, containing acetylenic impurities, and, optionally, saturated hydrocarbon gases, through a particulate bed predominantly comprising a support material having high a surface area on which is dispersed at least one metallic element. Adsorption is carried out in an essentially dihydrogen-free atmosphere within the bed, effecting selective and reversible adsorption and/or complexing of the contained acetylenic contaminants with the adsorbent, thereby obtaining purified effluent which contains less than a predetermined level of the acetylenic impurities. Selective and reversible adsorption and/or complexing of the contained acetylenic impurities with the adsorbent is continued until levels of acetylenic impurities in the effluent stream increase to a predetermined level.

Abstract: Process for the removal of contaminant compounds containing one or more heteroatoms of sulfur, nitrogen and/or oxygen from hydrocarbon streams characterized in that it comprises:an adsorption step in which said compounds are adsorbed by means of an adsorber essentially consisting of silica gel, possibly modified with one or more metals selected from the elements of groups IVb, Vb, VIb, VIII, Ib, IIb or from tin, lead or bismuth, carried out at a temperature of between 0.degree. and 150.degree. C. and at a pressure of between 1 and 20 atm;an optional washing step with polar solvents or hydrocarbons;and a regeneration step for removing the substances adsorbed by means of thermal treatment in a flow of inert gas carried out at a temperature of between 100.degree. and 200.degree. C.

Abstract: Process for selectively removing oxygenated contaminants from streams prevalently containing hydrocarbons with from 3 to 8 carbon atoms characterized in that it comprises an adsorption step wherein said contaminants are adsorbed by an adsorbent essentially consisting of silica gel at a temperature of between 0 and 150.degree. C. and a pressure of between 1 and 20 atms and a regeneration step for removing the adsorbed substances by thermal treatment in a stream of insert gas carried out at a temperature of between 100 and 200.degree. C.

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 selectively removing nitrogenated and/or sulfurated contaminants from streams prevalently containing hydrocarbons with from 3 to 8 crbon atoms characterized in that it comprises an adsorption step wherein said contaminants are adsorbed by an adsorbent essentially consisting of silica gel at a temperature of between 0 and 150.degree. C. and at a pressure of between 1 and 20 atm and a regeneration step to remove the adsorbed substances by thermal treatment in a stream of insert gas carried out at a temperature of between 100 and 200.degree. C.

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: Processes using heterogeneous adsorbents are disclosed for purification of olefins such as are typically produced by thermal cracking of suitable hydrocarbon feedstocks, by passing a stream of olefin having from 2 to about 8 carbon atoms, containing acetylenic impurities having the same or similar carbon content, and optionally saturated hydrocarbon gases, through a particulate bed of predominantly a support material having high surface area on which is dispersed at least one metallic element. Adsorption is carried out in an essentially dihydrogen-free atmosphere within the bed, selective and reversible adsorption and/or complexing of the contained acetylenic contaminants with the adsorbent, and thereby obtain purified effluent which contains less than a predetermined level of the acetylenic impurities.

Abstract: A process to separate multimethyl-branched alkanes from a mixture of multimethyl-branched alkanes, monomethyl-branched alkanes, and normal alkanes has been developed. The mixture is introduced to a simulated moving bed of solid adsorbent particles having the selectivity normal alkanes>monomethyl-branched alkanes>multimethyl-branched alkanes. The adsorbent may be silicalite, ferrierite, zeolite Beta, MAPO-31, SAPO-31, SAPO-11, zeolite X ion exchanged with alkaline cations, alkaline earth cations, or a mixture thereof, and zeolite Y ion exchanged with alkaline cations, alkaline earth cations, or a mixture thereof. A raffinate stream enriched in multimethyl-branched alkanes is removed from the simulated moving bed.

Abstract: A process for separating paraxylene at very high purity from a charge of xylene isomers, comprising a selective adsorption of a fraction that is rich in paraxylene, at least one high-temperature crystallization of this fraction, and an isomerization of the fraction depleted of paraxylene, recycling the mother liquor to the selective adsorption optionally via a clay treatment followed optionally by a distillation of the treatment effluent, and optionally introducing the mother liquor into a distillation unit, wherein the crystallization can comprise several high-temperature stages.

Abstract: A process is set forth for the production of a carbon monoxide stream from a feed stream comprising carbon monoxide, hydrogen, carbon dioxide, methane, nitrogen and moisture. The process comprises contacting the feed stream at elevated pressure with a layered adsorbent bed comprising (i) a pretreatment adsorbent in order to adsorb moisture preferentially over methane, nitrogen and carbon dioxide and (ii) a main adsorbent in order to adsorb carbon monoxide preferentially over hydrogen, carbon dioxide, methane and nitrogen. A key to the present invention is that a carbon-based adsorbent is used as the pretreatment adsorbent.

Abstract: A method for the desulfurization of hydrocarbons by desulfurizing unsaturated hydrocarbons or hydrocarbon materials containing unsaturated hydrocarbons, in the presence or absence of hydrogen, using a copper-zinc desulfurizing agent prepared by the co-precipitation method. By this method, the sulfur content of the hydrocarbons can be reduced while suppressing hydrogenation of the unsaturated hydrocarbons.

Abstract: Phosphates can be removed from a hydrocarbon stream by contacting said stream with a ceramic formed of a basic material which is insoluble in the hydrocarbon stream. A ceramic as used in this patent document is a solid solution formed by calcination of a compound. The removal of the organic acid is accomplished at temperatures ranging from 20.degree. C. to 400.degree. C., a preferred temperature is between 200.degree. C. and 370.degree. C. A hydrocarbon stream consists of C.sub.5 + hydrocarbons. The basic material can be made up of one or more alkaline earth oxides, alkaline earth compounds, alkaline metal compounds, group IIIA element compounds, group IVA element compounds, group VIA element compounds. Preferred alkaline earth oxides are sodium, magnesium, potassium, calcium, aluminum and silicon. The support for the basic material can be made from any inorganic oxide.

Abstract: The present invention relates to a capture mass comprising an essentially alumina-based extruded support, and constituted by a plurality of juxtaposed agglomerates, optionally at least one oxide or a sulphide of a metal constituted by copper, molybdenum, tungsten, iron, nickel or cobalt in which the sum S of metals from the group constituted by copper, molybdenum, tungsten, iron, nickel and cobalt is in the range 0 to 70% by weight, and characterized in that each of these agglomerates is present partly in the form of packs of flakes and partly in the form of needles being uniformly dispersed both around the packs of flakes and between the flakes.The invention also relates to its use in a fixed bed reactor to eliminate heavy metals from a hydrocarbon-containing feed.

Abstract: A process for treating gas streams containing hydrogen and hydrocarbons. The process includes a membrane conditioning step to remove C.sub.5 -C.sub.8 hydrocarbons, followed by a selective adsorption or membrane separation step to separate hydrogen from methane. The membrane conditioning step uses a membrane selective for C.sub.5 -C.sub.8 hydrocarbons over hydrogen.

Abstract: A method providing enhanced heat integration in isomerization processes having an isomerization reactor operating at a temperature less than about 232.degree. C. (450.degree. F.) and an adsorption zone operating at a temperature greater than about 260.degree. C. (500.degree. F.) has been developed. The method begins with flowing a fresh feed stream containing normal and non-normal hydrocarbons to either the isomerization reactor or the adsorption zone. A variable mass flow desorption effluent containing at least normal hydrocarbons is flowed to the isomerization reactor to form a reactor effluent containing normal hydrocarbons and isomerized non-normal hydrocarbons. The reactor effluent is cooled and separated into an adsorber feed stream and a hydrogen purge gas which are each conducted to an adsorption zone. In the adsorption zone, the normal hydrocarbons are adsorbed and the non-normal hydrocarbons are withdrawn and collected.

Abstract: Petrochemicals are produced by the vapor phase reaction of a hydrocarbon with air in the presence of a suitable catalyst. The petrochemical product is removed from the product gas stream, and part or all of the remaining gas stream is passed through a bed of hydrophobic adsorbent, which adsorbs mainly the unreacted hydrocarbon from the gas stream without adsorbing water vapor. The adsorbed hydrocarbon is purged from the bed with air, and the air-hydrocarbon mixture is recycled to the partial oxidation reactor.

Abstract: An adsorbent product for the adsorption of trace elements of sulfur, arsenic, mercury, compounds which contain these elements or metal hydrides from a hydrocarbon gas stream, preferably an olefinic or paraffinic stream, wherein the adsorbent product is iron oxide and manganese oxide placed on a support material, preferably aluminum oxide. Also disclosed is a process for the use of this adsorbent product for the removal of trace elements of arsenic, mercury and sulfur or compounds containing those elements or metal hydrides from a hydrocarbon gas stream, preferably an olefinic or paraffinic gas stream.

Abstract: Carbonyl compound contaminants are removed from hydrocarbon streams containing olefins for use, for example, in the process for the skeletal isomerization of olefins by pretreating the hydrocarbon stream by passing it over an acidic catalyst at elevated temperatures in the range of 100-400.degree. C. under conditions to react the carbonyls to form reaction products which are deposited onto the catalyst.

Abstract: Integrated process for the production of butene-1 which comprises feeding a C.sub.4 hydrocarbon stream to a separation unit of butene-1 and recycling the remaining stream to the same unit after treatment in a bond isomerization section to convert the remaining butenes-2 into butene-1, a molecular sieve separation unit is inserted in the cycle operating with the hydrocarbons in a vapour phase, for the purge of the paraffins.

Abstract: Removal of aromatic sulfur compounds from an FCC feedstock with minimal adsorption of aromatic hydrocarbons is achieved using a zeolite Y exchanged with alkali or alkaline earth cations. KY is an especially effective adsorbent. Where the KY is impregnated with a group VIII metal, particular palladium or platinum, the adsorbent is effectively regenerated by treatment with hydrogen at elevated temperatures.

Abstract: This invention is a process for removing minor amounts of organic halide e.g., organic chloride, contaminants from hydrocarbon feedstocks by contact with a regenerable solid adsorbent comprising a metal and/or metal hydride selected from nickel, cobalt or iron, or mixtures thereof on a porous refractory support, such as silica, whereby the halide present in the hydrocarbon feedstock is converted substantially to an insoluble metal halide salt of the supported metal or metal hydride with the hydrocarbon feedstock being recovered from the contacting step substantially free of organic halide contaminant. Also disclosed is a process for regeneration of the adsorbent loaded with metal halide from the hydrocarbon feedstock contacting step and an integrated process where the regenerated adsorbent is reused to remove additional organic halide from the hydrocarbon feedstock.

Abstract: A process is provided for reducing the sulfur content of a hydrocarbon stream, wherein a hydrocarbon stream containing sulfur constituents is contacted with a sorbent under temperature and pressure conditions of low severity. The sorbent includes a metal-exchanged zeolite selected from a group consisting of Y zeolites, ultra-stable Y zeolites, and mixtures thereof. A preferred sorbent is a fluid catalytic cracking (FCC) catalyst having a rare earth metal exchanged Y zeolite or ultra-stable Y zeolite. The sorbent adsorbs sulfur constituents contained in the hydrocarbon stream upon contact therewith to reduce the sulfur content of the hydrocarbon stream.

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: Applicant has discovered a new zeolite containing composition and a process for preparing the same. The composition is unique in that the zeolite crystals making up one layer of the composition pack in a manner such that the composition is essentially continuous with no large scale voids even when the zeolite layer is <10 .mu.m thick. Thus, the present invention is directed toward a composition comprised of a porous substrate and a layer of zeolite crystals wherein said layer of zeolite crystals is a polycrystalline layer with at least 99% of said zeolite crystals having at least one point between adjacent crystals that is .ltoreq.20 .ANG. and wherein at least 90% of said crystals have widths of from about 0.2 to about 100 microns (preferably about 2 to about 50 microns) and wherein at least 75% of said crystals have a thickness of within 20% of the average crystal thickness. Preferably the composition has at most 1 Volume % voids in the zeolite layer. Use of the composition is also described.

Abstract: An activated carbon based adsorbent carrying an acid is provided for eliminating mercury or mercury compounds contained in hydrocarbons. Preferably the activated carbon base is provided with more than 80 ml/g micropore volume having radii less than 8 angstroms. Preferably the acid carried on the activated carbon is hydrochloric acid, sulfuric acid, or phosphoric acid. Hydrochloric acid is most preferred. The active carbon base is preferably manufactured by activating a carbonaceous material in an atmosphere comprising less than 30 vol. % water vapor. The adsorbent can be used to eliminate mercury or mercury compounds contained in hydrocarbons by contacting the adsorbent with the hydrocarbons in liquid phase. Particular hydrocarbons include naphtha and intermediates of oil products or petrochemical products. Minimal amounts of carried acid are desorbed from the adsorbent to the hydrocarbons.

Abstract: Hydrocarbon fluid catalytic cracking (FCC) plants are debottlenecked by subjecting part or all of the wet gas stream leaving the main fractionator overhead receiver to pressure swing adsorption to remove methane and hydrogen from this gas stream prior to its introduction into the wet gas compressor. This allows debottlenecking of the compressor system. It can allow the reduction in pressure in the system back to the catalyst regenerator. The reduction in pressure in the catalyst regenerator makes it possible to increase the rate of regeneration of catalyst. Consequently, the rate of hydrocarbon throughput in the FCC plant can be increased.

Abstract: A process for treating waste plastics includes adding the waste plastics and a catalyst into a reactor for catalytic cracking reaction at 280.degree.-480.degree. C., removing the solid impurities in the generated vapor, condensing the vapor in condenser, and returning the non-condensable gas to be burnt in the heating furnace, distilling and separating the condensate to obtain gasoline and diesel oil which will be stabilized to get high quality gasoline and diesel oil. The equipment includes an automatic hydraulic feeder, a reaction vessel, a gas settler, a condenser series, a vacuum discharge device for solid residue, a rectification tower, mixing tanks, and a final product tank.

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: An adsorption arrangement in combination with a catalytic hydrocarbon conversion process suspends non-hydrocarbon materials that act to enhance the operation of the conversion zone by using an adsorption zone arrangement to keep the compounds in recirculation about the reaction zone and integrates the adsorption zone arrangement with a chiller to increase the recovery of C.sub.4 hydrocarbons. The process of this invention is particularly useful for the isomerization of hydrocarbons wherein the adsorption zone arrangement operates to maintain chloride compounds in the reaction zone and to prevent contamination of product streams with the chloride compounds while increasing the recovery of C.sub.4 hydrocarbons. This invention can be used in combination with traditional adsorptive methods of removing contaminant from feedstreams that enter reaction zones.

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: The present invention relates to a process for dechlorinating a spent lubricating oil fraction, optionally mixed with another hydrocarbon stock. Upstream of the recycling operation in refining the spent oil, the latter is subjected to a dechlorination operation at least partially by passing it on a bed of particles (6) of a composition which neutralizes by absorption and containing, as active compound capable of fixing the chlorine, at least one metal oxide and/or at least one metal hydroxide.

Abstract: A mixed aromatic stream is hydrotreated to remove olefins and fractionated to separate C.sub.9 + heavies in a distillation column reactor and the C.sub.8 and lighter material is fed to a selective adsorption unit where the para-xylene is removed. The para-xylene depleted raffinate therefrom may be subjected to isomerization to form additional para-xylene. The effluent from the isomerization can be fed to the distillation column reactor for hydrogenation of any olefins formed during the isomerization or directly to the adsorption unit.

Abstract: A process for separating a product from a multicomponent feedstream to an adsorption apparatus or system. The apparatus or system may comprise a moving-bed or a simulated moving-bed adsorption means. The product comprises at least one organic compound, such as an aryl compound with alkyl substitutes. The conduits used to supply the feedstream to the apparatus or system are flushed with media of multiple grades. Amounts of the media are sufficient to fill the conduits. The process achieves improvements in the efficiency of adsorption separation, the capacity of adsorption apparatus and systems, and the purity of product attainable by adsorption process.