Abstract: A process for separating multibranched paraffins comprised in a hydrocarbon feed comprising hydrocarbons containing 5 to 8 carbon atoms per molecule comprises a separation unit functioning by adsorption and contains at least one zeolitic adsorbent with a mixed structure with principal channels with openings defined by a ring containing 10 oxygen atoms and secondary channels with openings defined by a ring of at least 12 oxygen atoms, the secondary channels only being accessible to the feed to be separated via the principal channels. Particular zeolitic adsorbents of the invention are zeolites with structure types EUO, NES and MWW. NU-85 and NU-86 zeolites are also particularly suitable for carrying out the process of the invention.

Abstract: The performance of an adsorptive separation process recovering para-xylene from a C8 aromatic hydrocarbon feed mixture is improved by operating the process at higher desorbent purity. The improved performance allows for tradeoffs in other operating parameters and rates or improved product rates. The process preferably employs a barium and potassium exchanged zeolitic molecular sieve as the adsorbent and toluene as the desorbent.

Abstract: The invention relates to an effective method of separating polycyclic aromatic hydrocarbons by means of a chromatographic separation method. This is achieved by using, according to the invention, calixarene-modified separation phases as stationary phase for chromatography in order to separate polycyclic aromatic hydrocarbons. The calixarene-modified stationary phases are particularly suitable for separating polycyclic aromatic hydrocarbons in liquid chromatography separation methods.

Abstract: For co-production of metaxylene and paraxylene from a hydrocarbon feedstock in a simulated moving bed in a chromatographic column (1) that contains a number of beds 1, 2,3, 4 . . . of an adsorbent, interconnected in a loop, the column comprises an injection of the feedstock, a draw-off (14) of a first raffinate, a draw-off (17) of a second raffinate that comprises metaxylene, an injection of desorbent and a draw-off of an extract that delivers paraxylene. The injection positions and the draw-off position of the extract are offset periodically by one bed in the direction of flow of the main flux that circulates in the column. First raffinate (14) that comprises desorbent, orthoxylene, metaxylene and ethylbenzene is drawn off continuously or intermittently, and second raffinate (17) R2 that comprises orthoxylene and metaxylene is drawn off intermittently. The second raffinate is distilled in such a way as to recover orthoxylene and metaxylene separately with at least 99% purity and with an improved yield.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C8 aromatics stream produced by toluene conversion uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the pX and EB giving a pX/EB-rich effluent. A stream of non-adsorbed mX and oX may be obtained before desorbing pX and EB.

Abstract: The amount of the adsorbent needed to recover a set quantity of monomethyl branched C10-C15 paraffins from a mixture comprising normal paraffins and other nonnormal hydrocarbons such as di-isoparaffins, di-isoolefins, naphthenes and aromatics by simulated moving bed adsorptive separation is reduced by adjusting three operating factors: percentage recovery of the paraffin, operating temperature and cycle time. This reduces the capital cost of the process. The recovered monomethyl hydrocarbons may be used to form a monomethyl branched alkylaromatic hydrocarbon useful as a detergent precursor.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with para-xylene and ethylbenzene, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the para-xylene and ethylbenzene. The process effluent is rich in para-xylene and ethylbenzene. A stream of non-adsorbed meta-xylene and ortho-xylene may be obtained prior to desorption of para-xylene and ethylbenzene.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with crystallization to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is crystallized to obtain para-xylene product.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with simulated moving bed adsorption (SiMBAC) to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is subjected to SiMBAC to obtain para-xylene product.

Abstract: Fractional distillation performed to recover butane used as a desorbent component for adsorptive separation is integrated with the other fractionation of the raffinate stream of a C5-C6 paraffin adsorptive separation zone. A single fractionation column is employed to recover the desorbent butane, a highly branched paraffin product stream and a mono-branched paraffin rich recycle stream, thus reducing the cost of the process.

Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single column. Both streams are fractionated to recover desorbent, which is removed at one end of a dividing wall column, while separate extract and raffinate products are removed from the other end of the column.

Abstract: The present invention relates to agglomerated zeolite adsorbents based on faujasite with an Si/Al ratio such that 1≦Si/Al≦1.15, at least 70% exchanged with barium and optionally with potassium, and on a binder, preferably a zeolitizable binder. They are obtained by agglomerating zeolite powder with a binder, followed by exchange of the zeolite ions for barium ions and activation of the adsorbents thus exchanged. These adsorbents are particularly suitable for the adsorption of the para-xylene contained in aromatic C8 hydrocarbon fractions in the liquid phase, in processes of simulated fluid-bed type.

Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single integrated fraction column. Both streams are fractionated to recover desorbent, which is removed at one end of a dividing wall column, while separate extract and raffinate products are removed from the other end of the column. A specific embodiment includes the use of the integrated fractionation column in an isomerization application.

Abstract: Two separate paraffinic hydrocarbon products, such as normal and monomethyl branched C10-C23 paraffins, are recovered from a mixture comprising the product hydrocarbons and many other hydrocarbons in a process employing two adsorptive separation zones in series. A single desorbent comprising a light paraffin is used in both zones and recovered in a single system, thus reducing capital and operating costs. The recovered paraffinic hydrocarbons may then be dehydrogenated and reacted with benzene to form alkylaromatic hydrocarbons useful as a detergent precursor.

Abstract: An adsorptive separation process for preparing the separate feed streams charged to naphtha reforming unit and a steam cracking unit is presented. The feed stream to the overall unit is fractionated to yield a C5 stream and a second stream containing the rest of the feed, which is passed into the adsorptive separation unit. The C5 stream is utilized as the desorbent in the adsorptive separation. The adsorptive separation separates the C6-plus components of the feed stream into a normal paraffin stream, which is charged to the steam cracking process, and non-normal hydrocarbons which are passed into a reforming zone. The invention improves the yields from both downstream units.

Abstract: Construction and operational costs of recovering the high-octane components of an isomerization raffinate product of a simulated moving bed adsorptive separation process units are reduced by employing a dividing wall column to perform the separation. The raffinate product stream is passed into the column at an intermediate point on the first side of the dividing wall, with the column delivering the low-octane raffinate components as a sidedraw from the opposite side of the dividing wall. A stream of higher octane components are removed both as an overhead stream and a bottoms stream. The sidedraw may be recycled to the isomerization zone.

Abstract: Construction and operational costs of recovering the extract or raffinate product of a simulated moving bed adsorptive separation process units are reduced by employing a dividing wall column to perform the separation. The raffinate or extract stream is passed into the column at an intermediate point on the first side of the dividing wall, with the column delivering the adsorptive separation product as a sidedraw from the opposite side of the dividing wall. A stream of co-adsorbed impurity is removed as an overhead stream and desorbent is recovered as a net bottoms stream.

Abstract: For co-production of metaxylene and paraxylene from a hydrocarbon feedstock in a simulated moving bed in a chromatographic column (1) that contains a number of beds 1, 2, 3, 4 . . . of an adsorbent, interconnected in a loop, the column comprises an injection of the feedstock, a draw-off (14) of a first raffinate, a draw-off (17) of a second raffinate that comprises metaxylene, an injection of desorbent and a draw-off of an extract that delivers paraxylene. The injection positions and the draw-off position of the extract are offset periodically by one bed in the direction of flow of the main flux that circulates in the column. First raffinate (14) that comprises desorbent, orthoxylene, metaxylene and ethylbenzene is drawn off continuously or intermittently, and second raffinate (17) R2 that comprises orthoxylene and metaxylene is drawn off intermittently.

Abstract: A process for the production of at least one isomer of xylenes comprising a simulated moving-bed adsorption (8) of a C8-aromatic feedstock (1) that delivers a paraxylene-rich fraction (9) that is optionally purified after a distillation (16) by at least one high-temperature crystallization (5) and a fraction (10) that is low in paraxylene is described. Fraction (10) is distilled and then isomerized (21) in the presence of an EUO-structural-type catalyst. The lightest hydrocarbons are removed from the isomerization effluent in a first distillation (23) then naphthenes in a second distillation (26), and distilled isomerization effluent (2) that results therefrom is recycled at least in part in adsorption (8). A mother liquor (3) that results from the crystallization stage is recycled at least in part in adsorption (8).

Abstract: A process for co-production of paraxylene and ethylbenzene comprises: (A) an adsorption stage of a feedstock of xylenes and ethylbenzene in a simulated moving bed that produces an extract of pure paraxylene and an ethylbenzene-rich raffinate; (B) an adsorption stage in a simulated moving bed, of raffinate from which desorbent has been removed that supplies an essentially pure ethylbenzene extract and an orthoxylene and metaxylene raffinate that contains desorbent; (C) a recover stage for the desorbent; (D) an isomerization stage for the orthoxylene and metaxylene raffinate in the presence of a catalyst that comprises an EUO-type zeolite; and (E) a stage for recycling the isomerate that is produced with adsorption.

Abstract: For co-production of metaxylene and paraxylene from a feedstock (line-4) of hydrocarbons, there is employed a simulated moving bed chromatographic column 5 having at least five zones and which delivers an extract, a raffinate and an intermediate raffinate. The feedstock has an ethylbenzene content of less than 5% by weight, and the chromatographic column comprises at least twenty-five beds, of which at least five beds are in zone 3B. The raffinate is distilled (31) to recover the metaxylene at a purity of at least 99% and orthoxylene. The extract is distilled (7, 10) to recover the paraxylene at a purity of at least 99.6%. The recovered isomers can be synthesized into isophthalic acid and terephthalic acid.

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 paraffinic and possibly naphthenic and/or aromatic hydrocarbons, and in some cases olefinic hydrocarbons, a chromatographic separation process uses a separation zone operating by adsorption. The process of the invention is of particular application when coupled with a hydro-isomerization process, which selectively recycles straight chain and mono-branched paraffins, necessary for paraffins containing at least 7 carbon atoms.

Abstract: A method for recovering small bandgap fullerenes, including metallofullerenes, from soot by passivating individual fullerenes and/or metallofullerenes to an anionic configuration. The addition of extra electrons to a metallofullerene or small bandgap fullerene breaks the inter-fullerene bonding in the solid material, and the resulting anions are soluble in organic electrochemical solvents. Once dissolved, the small bandgap fullerenes can be plated out or precipitated by returning them to a neutral state.

Abstract: The present invention relates to methods for removing VOCs from an aqueous polymer dispersion (e.g., an SBR latex) in which the dispersion is contacted with a stripping medium in the presence of a particulate adsorbent such as activated carbon. This process results in the rapid and economical removal of VOCs from polymer dispersions.

Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single column. Both streams are fractionated in the same column to recover desorbent, which is removed at the bottom of the column. The bottom of the column is divided into a reboiler sump section and a bottoms product-desorbent inventory section, with this reducing the equipment required in the overall process.

Abstract: The invention relates to a process for adsorption of polymerization inhibitors from ethylenically unsaturated monomers, in which these inhibitors are placed in contact with an alumina exhibiting a volume of pores of diameter greater than 100 Å of at least 0.20 ml/g, preferably of at least 0.25 ml/g, still more preferably of at least 0.30 ml/g, and a specific surface of at least 30 m2/g, preferably of at least 60 m2/g, still more preferably of at least 80 m2/g.

Abstract: A system that makes it possible to merge at least four fluids with a column for separating a feedstock, for example, in a simulated moving bed, comprises at least one trunnion-mounted ball valve, whereby this valve comprises at least one means that makes it possible to circulate one or more fluids, this fluid is placed inside the valve to ensure communication between two zones of the column or between at least one of said zones and at least one point that is outside of the column, and several openings (OA, OB) that are placed to ensure the circulation of fluids according to the stages that are necessary to the separation process that is carried out in said column.

Abstract: Paraxylene and ethylbenzene are produced from an aromatic hydrocarbon feedstock by using adsorption zones in a simulated fluid bed. The feedstock is first passed into a first adsorption zone to produce a first paraxylene-rich fraction and a second ethylbenzene-rich fraction. The second fraction is then passed into a second adsorption zone to produce a third fraction containing essentially pure ethylbenzene and a fourth fraction containing a majority of orthoxylene and metaxylene. The fourth stream is then passed into an isomerization zone to produce an isomerate which is then recycled back to the first adsorption zone.

Abstract: In a method for separating at least one alkylnaphthalene from a stock mixture containing at least two alkylnaphthalenes selected from the group consisting of monoalkylnaphthalenes and dialkylnaphthalenes, a column packed with an optically active chromatographic packing is used for separation. The method can effectively separate a variety of alkylnaphthalenes from a mixture thereof.

Abstract: A process for the continuous isomerization of an alkane to produce an isomerized product through contacting the alkane with a simulated moving bed acting as a catalyst for isomerization and an adsorbent for the alkanes has been developed. The alkane may be n-butane and the isomerized product 2-methylpropane, the alkane may be n-pentane and the isomerized product 2-methylbutane or 2,2-dimethylpropane, the alkane may have from 6 up to about 8 carbon atoms with no more than one methyl branch and the isomerized product having the same number of carbon atoms and at least two methyl branches, or the reactant may be a mixture of the foregoing alkanes with the corresponding isomerized products being formed. In a zone of the simulated moving bed, the alkanes are catalytically isomerized to form the isomerized products. The unreacted alkanes are adsorbed, and the isomerized products are collected.

Abstract: A process for isomerizing a mixture of alkanes containing pentanes and at least one alkane having from 6 to about 8 carbon atoms and no more than one methyl branch has been developed.

Abstract: A process for the continuous isomerization of an alkane to produce an isomerized product through contacting the alkane with a simulated moving bed acting as a catalyst for isomerization and an adsorbent for the alkanes has been developed. The alkane may be n-butane and the isomerized product 2-methylpropane, the alkane may be n-pentane and the isomerized product 2-methylbutane or 2,2-dimethylpropane, the alkane may have from 6 up to about 8 carbon atoms with no more than one methyl branch and the isomerized product having the same number of carbon atoms and at least two methyl branches, or the reactant may be a mixture of the foregoing alkanes with the corresponding isomerized products being formed. In a zone of the simulated moving bed, the alkanes are catalytically isomerized to form the isomerized products. The unreacted alkanes are adsorbed, and the isomerized products are collected.

Abstract: To continuously produce and separate high purity p-xylene from a C.sub.8 aromatic hydrocarbon charge, successive use is made in combination of (1) a stage of separating low-purity p-xylene (75 to 98%) by simulated moving bed adsorption chromatography, with a ratio for the solvent to charge flow rates of 1.2 to 2.5; (2) a stage of purifying and washing the low-purity p-xylene by recrystallization (-25.degree. to +10.degree. C.); (3) a stage of catalytic isomerization of the charge which has been p-xylene-depleted by the separating stage (1); and recovering an isomerate which is then recycled to the charge. The solvent for desorption in stage (1) and washing in stage (2) is advantageously toluene.

Abstract: The disclosure describes highly specific tryptase polyclonal antibodies, and a method to purify the antibodies. Specifically, the invention relates to polyclonal antibodies which have the capacity to capture tryptase out of solution, a process to generate the antibodies, and an enzyme-linked immunosorbent assay (ELISA) for human tryptase which utilizes the antibodies.

Abstract: A process for isomerizing a mixture of alkanes containing pentanes and at least one alkane having from 6 to about 8 carbon atoms and no more than one methyl branch has been developed.

Abstract: A process for the continuous isomerization of an alkane to produce an isomerized product through contacting the alkane with a simulated moving bed acting as a catalyst for isomerization and an adsorbent for the alkanes has been developed. The alkane may be n-butane and the isomerized product 2-methylpropane, the alkane may be n-pentane and the isomerized product 2-methylbutane or 2,2-dimethylpropane, the alkane may have from 6 up to about 8 carbon atoms with no more than one methyl branch and the isomerized product having the same number of carbon atoms and at least two methyl branches, or the reactant may be a mixture of the foregoing alkanes with the corresponding isomerized products being formed. In a zone of the simulated moving bed, the alkanes are catalytically isomerized to form the isomerized products. The unreacted alkanes are adsorbed, and the isomerized products are collected.

Abstract: This invention relates to use of synthetic porous crystalline material MCM-58 as a sorbent composition for separating at least one component from a mixture of components.

Abstract: An adsorptive process to separate the components of a solution of linear and branched hydrocarbons into a linear hydrocarbon portion and a branched hydrocarbon portion where the adsorbent is an alkylene-bridged polysilsesquioxane has been developed. The hydrocarbon components to be separated may be alkanes, alkenes, or alkynes, and the alkylene-bridging group of the adsorbent may contain from about 2 to about 14 carbon atoms. A specific embodiment of the invention is one where the process is operated in the simulated moving bed mode.

Abstract: A process to separate at least two classes of hydrocarbons of a solution using an alkylene-bridged polysilsesquioxane adsorbent has been developed. The classes of hydrocarbons to be separated may be saturated hydrocarbons, unsaturated aliphatic hydrocarbons and aromatic hydrocarbons. The alkylene-bridging group may contain from about 2 to about 14 carbon atoms. A specific embodiment of the invention is one where the components of a solution of aromatic, unsaturated aliphatic, and saturated hydrocarbons are separated into an aromatic hydrocarbon portion, an unsaturated aliphatic hydrocarbon portion, and a saturated hydrocarbon portion where the adsorbent is an alkylene-bridged polysilsesquioxane.

Abstract: An adsorptive process to separate the components of a solution of linear and branched hydrocarbons into a linear hydrocarbon portion and a branched hydrocarbon portion where the adsorbent is an aryl-bridged polysilsesquioxane has been developed. The hydrocarbon components to be separated may be alkanes, alkenes, or alkynes, and the aryl-bridging group of the adsorbent may be phenylene, diphenylene, terphenylene or anthrylene. A specific embodiment of the invention is one where the process is operated in the simulated moving bed mode.

Abstract: A process to separate at least two classes of hydrocarbons of a solution using an aryl-bridged polysilsesquioxane adsorbent has been developed. The classes of hydrocarbons to be separated may be saturated hydrocarbons, unsaturated aliphatic hydrocarbons and aromatic hydrocarbons. The aryl-bridging group may be phenylene, diphenylene, terphenylene, or anthrylene. A specific embodiment of the invention is one where the components of a solution of aromatic, unsaturated aliphatic, and saturated hydrocarbons are separated into an aromatic hydrocarbon portion, an unsaturated aliphatic hydrocarbon portion, and a saturated hydrocarbon portion where the adsorbent is an aryl-bridged polysilsesquioxane.

Abstract: A process for separating polar and non-polar constituents from coal tar distillates, comprising passing the distillates over a separation column together with an eluting agent. According to the invention the process comprises mixing a tar oil distillate with a non-polar solvent, passing this mixture over a separation column which contains a stationary phase and eluting with a non-polar solvent, the eluting agent being collected together with the substances dissolved therein, followed by eluting with a more polar eluting agent or with a plurality of eluting agents of increasing polarity, and separately collecting the more polar eluting agent or the plurality of eluting agents of increasing polarity, together with the substances dissolved therein, followed by isolating the substances dissolved in the non-polar and in the polar solvents, respectively, utilizing known techniques.

Abstract: Methods of separating and classifying the relative amounts of two or more classes of hydrocarbon molecules in a sample are disclosed wherein an input stream comprising a mobile phase and the sample is injected into a chromatographic column, and an effluent stream exiting a chromatographic column is split into a first effluent stream and a second effluent stream. The mass of carbon in each of the classes of hydrocarbons in the first effluent stream is determined, preferably using a flame ionization detector, and the second effluent stream is directed through a variable restrictor, allowing the pressure and mass flow rate of the input stream to be independently controlled and improved results obtained. In a preferred embodiment the present invention also includes identifying the hydrocarbon molecules in the second effluent stream in order to verify the analysis or provide additional data, preferably by using an ultraviolet detector.

Abstract: Hydrocarbon oils such as diesel fuels, turbine fuels and intermediate distillates may be subjected to quantitative analysis of their saturate, aromatic and polar components by supercritical fluid chromatography using carbon dioxide as the solvent. A sample of the oil is passed into a packed column of silica or the like whereby the respective fractions are separated and retained on the column. Supercritical carbon dioxide at selected pressure and temperature conditions is passed through the column to extract, separately, each of the fractions retained on the column. The extracted fraction and solvent are passed through a restrictor and expanded down to a pressure which will allow the solvent to evaporate and to permit retention or collection of the extracted fraction in a collector arrangement including a selector valve and plural collection containers.

Abstract: For the at least partial separation of aliphatic paraffins into at least one effluent comprising the least branched paraffins and at least one effluent comprising the most branched paraffins, use is made of at least one adsorbent bed comprising at least one grafted microporous solid. A preferred use of the invention relates to the treatment of a charge obtained from an isomerization zone, whereby at least one adsorbent bed makes it possible to separate the charge into a first effluent comprising the normal paraffins and a second effluent, and at least one adsorbent bed on which passes the second effluent, comprising at least one grafted microporous solid, making it possible to obtain a third effluent comprising the monomethyl branched paraffins and a fourth effluent comprising the polymethyl branched paraffins.

Abstract: Compositions of high-purity natural beta-carotene and of the 9-cis isomer of beta-carotene are provided, as are methods for the production of these compositions from plant matter, conveniently algae such as Dunaliella species. Typically, the compositions contain at least about 5% 9-cis beta-carotene and less than or equal to 40% of all-trans-beta-carotene, and in some cases may contain 75% 9-cis beta-carotene or higher. The compositions are suitable for administration to humans or other animals, particularly for oral delivery, in a variety of formulations and dosages as pharmaceutical agents or as dietary supplements.

Abstract: To continuously produce and separate high purity p-xylene from a C.sub.8 aromatic hydrocarbon charge, successive use is made in combination of (1) a stage of separating low-purity p-xylene (75 to 98%) by simulated moving bed adsorption chromatography, with a ratio of the solvent to charge flow rates ob 1.2 to 2.5; (2) a stage of purifying and washing the low-purity p-xylene by recrystallization (-25.degree. to +10.degree. C.); (3) a stage of catalytic isomerization of the charge which has been p-xylene-depleted by the separating stage (1); and recovering an isomerate which si then recycled to the charge. The solvent for desorption in stage (1) and washing in stage (2) is advantageously toluene.

Abstract: The separation of durene in high purity from coal tar or petroleum fractions by an adsorptive chromatographic process and liquid phase with lithium-exchanged X zeolite as the adsorbent and liquid aromatic desorbents.

Abstract: A hydrocarbon feedstock is simultaneously distilled into two or more fractions while trace concentrations of contaminants in the feedstock are absorbed onto a sorbent packing material during distillation operation. The sorbent packings contain active metal components supported on porous refractory oxides. Such sorbent packings provide surfaces for mass transfer in the distillation process and concurrently absorb contaminants. Product boiling fractions from the absorption-distillation process are further processed over contaminant-sensitive catalysts such as reforming or isomerization catalyst.

Abstract: A chromatographic process able to separate para-xylene from C.sub.8 isomers and C.sub.9 aromatics. In the process, the para-xylene-containing feed mixture is contacted with an X zeolite adsorbent having barium or barium and potassium ions, at exchangeable cationic sites. The para-xylene components are selectively adsorbed onto the adsorbent. The non-adsorbed feed is then removed from the adsorbent and the para-xylene recovered by desorption with indan or an alkyl derivative of indan. Any C.sub.9 aromatic hydrocarbons and the other xylene isomers in the raffinate can be separated from these heavy desorbents by fractionation of the raffinate and the desorbent can be recycled to the process.