Abstract: A process scheme for the recovery of high purity p-xylene or p-xylene and ethyl benzene from C.sub.8 aromatics is described. In the process, zeolites such as ZSM-5 type, zeolite beta and ZSM-11 with optimum silica alumina ratio is used as the adsorbent and light hydrocarbons, such as C.sub.5 is used as the desorbent. The process system is operated isothermally at low temperature and low pressures.

Abstract: Organic feedstocks containing at least one impurity component which is more strongly adsorbed on molecular sieve adsorbents than the host feedstock are purified of the said impurity by passage in the liquid phase through a fixed bed of the adsorbent whereby the impurity is selectively adsorbed and the purified feedstock recovered in unusually high yield by a novel bed regeneration procedure involving the use of a portion of the purified feedstock in the vapor phase to countercurrently remove the liquid held in the bed void space, a relatively non-sorbable purge gas to sequentially displace the purified feedstock vapor from the bed followed by a displacement of the non-sorbable purge gas from the bed void space using another portion of the purified feedstock in the vapor phase, and finally cooling and refilling the bed in a direction cocurrent with the flow of feedstock into the bed during the adsorption purification stage with a portion of the purified feedstock in the liquid phase.

Abstract: Disclosed is a method of separating organic or organometallic materials under supercritical fluid conditions, the method comprising the steps of providing a bed of packing material selected from a metal oxide/hydroxide support material having phsophorous-containing organic molecules bonded to reactive sites on said support material, alumina and alumina-containing mixtures. The materials are introduced to the bed and a fluid is added to the bed under supercritical fluid conditions. The fluid removes one of the materials from the bed.

Abstract: The present invention relates to a new and integrated process involving the utilization of a primary adsorption bed containing a regenerable, physical absorbent and an auxiliary sorption bed containing a chemisorbent and an optional physical absorbent for the removal of sulfur compounds and water from a fluid stream, which process provides for higher yields, higher purity and lower costs.

Abstract: The present invention relates to a new and integrated process involving the utilization of a primary adsorption bed containing a regenerable, physical adsorbent and an auxiliary sorption bed containing a chemisorbent for the removal of sulfur compounds from a fluid stream, which process provides for higher yields, higher purity and lower costs. A system for removing sulfur compounds in accordance with the above process is also disclosed.

Abstract: A process is disclosed for catalytic conversion of hydrocarbons (e.g. hydroisomerization of unbranched paraffins) by passing a hydrocarbon-containing feed stream at hydrocarbon conversion conditions sequentially in opposite directions through at least part of a zone containing hydrocarbon conversion catalyst and subsequently through at least part of a zone containing adsorbent material capable of adsorbing unconverted hydrocarbons and sequentially passing a sweep fluid in the same direction as said feed stream through at least part of said zone containing absorbent material.

Abstract: A substituted benzene isomer mixture containing a meta-substituted benzene or 1,3,5-substituted benzene is contacted with an adsorbent of a faujasite type zeolite containing a Ag cation and/or a Cu cation, whereby the meta-substituted benzene or 1,3,5-substituted benzene is separated and recovered as a raffinate component.

Abstract: The viscosity index of synthetic lubricant stocks such as those produced by olefin oligomerization is increased by contacting such stocks with a solid acidic isomerization catalyst such as boron trifluoride at elevated temperatures, say above about 200.degree. C. The high viscosity index fractions of the resulting product may be sorbed by a shape-selective zeolite such as ZSM-5 and recovered to produce a high VI lubricant.

Abstract: A process for separating isoprene from isobutylene, isopentane, and pentene-1. The process uses an adsorbent comprising activated carbon or molecular sieve carbon to selectively adsorb isoprene from the other hydrocarbons. High purity isoprene is recovered by desorption using desorbent materials which include olefinic hydrocarbons. The process is particularly suited for a simulated moving bed apparatus.

Abstract: Method for removal of phenolic polymerization inhibitors from liquid conjugated olefin hydrocarbon by contacting said liquid hydrocarbon with a sorbent material comprising particulate acidified active carbon which sorbent has previously been oxidized by contact with a highly acidic oxidizing fluid. Optionally, after contact with the highly acidic oxidizing fluid the sorbent may be further treated in an alkaline environment with compounds of at least one of alkali metals, alkaline earth metals and ammonia. The sorbent material may be regenerated by heating, or by passing a heated non-oxidizing gas e.g., superheated stream there through.

Abstract: In a pressure swing adsorption process conducted in a plurality of cyclically interchangeable adsorbers, for recovering a hydrocarbon, e.g.

Abstract: Lubricant components of high viscosity index are selectively separated from hydrocarbon base stocks by a selective sorption process using an intermediate pore size zeolite such as ZSM-5 as the sorbent. The process is of particular utility with synthetic lubricant stocks produced by the oligomerization of light olefins. The sorbed components may be desorbed from the zeolite to recover a high VI lubricant.

Abstract: A process for separating a normal C.sub.6 olefin hydrocarbon from a mixture of the same with a C.sub.6 olefin branched chain and/or cyclic hydrocarbon. The process comprises contacting the mixture at separation conditions with a molecular sieve comprising a crystalline silica. The normal C.sub.6 olefin hydrocarbon is selectively retained and will be recovered from the molecular sieve by displacement with a displacement material comprising pentene-1 or butene-1. The process preferably employs a simulated moving bed.

Abstract: An improved technique for sorption of certain members of a ZSM-5 type of zeolites is provided. The class of zeolites is characterized by a silica to alumina mole ratio greater than 12 and a Constraint Index within the approximate range of greater than about 2 to about 12. The process of this invention involves sorption and/or selective separation of bicyclic fused-ring aromatic compounds, having a critical dimension less than 6.8 Angstrom units.

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 the separation of normal C.sub.4 hydrocarbons from isobutylene. A mixture of the normal C.sub.4 hydrocarbons and isobutylene is contacted with a molecular sieve comprising silicalite which is selective for the normal C.sub.4 hydrocarbons. The isobutylene is then recovered in the raffinate stream and the normal C.sub.4 hydrocarbons recovered by displacement with pentene-1.

Abstract: An improved hydrocarbon separation process by the selective sorption properties of certain members of a novel class of zeolites is provided. The novel class of zeolites is characterized by a silica to alumina mole ratio greater than 12 and a Constraint Index within the approximate range of greater than about 2 to about 12. The process of this invention involves selective separation of higher molecular weight hydrocarbon compounds in admixture with lower molecular weight hydrocarbon compounds within a homolgous series by contacting the respective mixture with a zeolite having a SiO.sub.2 /Al.sub.2 O.sub.3 mole ratio of at least about 12 and a Constraint Index with the approximate range of greater than 2 to about 12, to effect the selective sorption of said higher molecular weight hydrocarbon compounds by said zeolite.

Abstract: A continuous, cyclic, vapor-phase adsorption process for the separation of normal paraffins from a hydrocarbon feed mixture, providing improved efficiency of separation and continuity in product flows. For purposes of this process, a continuous flow of the feed mixture and a continuous flow of an eluent are passed in repetitions of a particular sequence of nine process steps to at least three molecular sieve adsorbent beds.

Abstract: A method of cyclic desorption of adsorption agents cyclically loaded with adsorbates is performed in two phases in which a mixture of a desorption vapor and an adsorption vapor is guided over an adsorption medium in a first adsorption phase, a pure desorption vapor is guided over an adsorption medium in a second adsorption phase, and a vapor mixture produced during the second adsorption phase is introduced into the first adsorption phase.

Abstract: A method is disclosed for regenerating a solid adsorbent which has been used to remove oxygen-containing hydrocarbonaceous compounds, water or sulfur-containing compounds from a hydrocarbon stream. The method is preferably applied to molecular sieves which have been used to remove ethers, alcohols and/or water from a light liquid phase hydrocarbon stream such as a stream which is rich in C.sub.4 hydrocarbons. The regeneration method includes stripping the adsorbent with a low temperature hydrogen-rich gas stream, which preferably has a temperature below about 200.degree. F., and then gradually increasing the temperature of the gas stream to customary regeneration temperatures.

Abstract: An adsorptive separation process for separating ethanol from a feed mixture comprising ethanol and water, which process comprises contacting the feed mixture with an adsorbent comprising activated carbon, selectively adsorbing substantially all of the ethanol to be separated to the substantial exclusion of the water and thereafter recovering high purity ethanol. A desorption step is used to desorb the adsorbed ethanol with the desorbent selected being capable of direct blending into motor fuel.

Abstract: An improved adsorption-desorption separation process is disclosed for separating close boiling fractions or isomers of a hydrocarbon feedstream containing mixed hydrocarbon fractions or isomers.

Abstract: An improved process for separating ortho aromatic isomers from a feed stream containing a mixture of aromatics by contacting the feed stream with a bed of the crystalline aluminosilicate adsorbent CSZ-1. The adsorbed ortho aromatic isomer is removed from the adsorbent by desorption.

Abstract: Normal paraffins are separated from a hydrocarbon vapor feedstream having 10 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil - containing feedstocks. A portion of the countercurrent, desorption purge effluent is employed as a hexane - containing cocurrent purge stream, thereby significantly reducing the required amount of n-hexane purge recycle material, and the size of the equipment and the energy consumed in the processing of said recycle stream. A portion of said countercurrent purge effluent can also be used to provide a source of n-hexane diluent for the gas oil - containing feedstocks, as can the cocurrent purge effluent, resulting in further reduction in required equipment and energy costs, and increasing adsorption efficiency and adsorbent utilization.

Abstract: A process for the separation of metaxylene from aromatic C.sub.8 hydrocarbons, particularly from ethylbenzene and paraxylene, wherein a first phase is provided in which the mixture of aromatic hydrocarbons is selectively adsorbed, in vapor phase, into a catalytic bed consisting of zeolite of the Y type, preliminarily exchanged with potassium, and in a second phase a desorption is effected with a suitable solvent. The process, carried out at a temperature of 150.degree. to 200.degree. C. and preferably at atmospherical pressure, permits the recovery of metaxylene, substantially pure and at a concentration much higher than that of the starting mixture.

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: A method for the removal of polymer from a straight-chain paraffin purge medium used in a monoolefin adsorption-desorption separation process comprising recycling a countercurrent purge step polymer containing straight-chain paraffin product for use as purge medium in the process without separation of polymer from the straight-chain paraffin and separating polymer from at least a portion of an adsorption step and a copurge step polymer containing straight-chain paraffin product and recycling the purified straight-chain paraffin for use as purge medium in the process.

Abstract: A continuous, cyclic, vapor-phase adsorption process for the separation of normal paraffins from a hyrocarbon feed mixture, providing improved efficiency of separation and continuity of product flows. For purposes of this process, a continuous flow of the feed mixture and a continuous flow of an eluent are passed in repetitions of a particular sequence of six process steps to at least three molecular sieve adsorbent beds.

Abstract: A continuous, cyclic, vapor-phase adsorption process for the separation of normal paraffins from a hydrocarbon feed mixture, providing improved efficiency of separation and/or continuity of product flows. For purposes of this process, a continuous flow of the feed mixture and a continuous flow of an eluent are passed in repetitions of a particular sequence of six process steps to at least three adsorbent beds.

Abstract: Normal paraffins are separated from a gas oil-containing hydrocarbon vapor feed stream having 16 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil-containing feedstock. Cocurrent purge effluent is used to provide a source of such n-hexane diluent, thereby reducing the equipment size and energy consumption for processing of the n-hexane purge recycle stream and increasing adsorbent utilization or the efficiency of the adsorption process.

Abstract: A continuous, cyclic, vapor-phase adsorption process for the separation of normal paraffins from a hydrocarbon feed mixture, providing improved efficiency of separation and continuity of product flows. For purposes of this process, a continuous flow of the feed mixture and a continuous flow of an eluent are passed in repetitions of a particular sequence of six process steps to at least four adsorbent beds.

Abstract: Normal paraffins are separated from a gas oil-containing hydrocarbon vapor feed stream having 16 to 25 carbon atoms per molecule in a constant pressure process employing a molecular sieve adsorbent and n-hexane for purging and for dilution of gas oil-containing feedstocks. Countercurrent purge effluent is used to provide a source of such n-hexane diluent, thereby effecting a savings in the amount of energy necessary to process the purge recycle stream and the size of the equipment used therefor.

Abstract: A process for recovering nitrobenzene, dichlorobenzene and/or trichlorobenzene from substantially undried exhaust gases or spent air containing these compounds, by passing said gases through a layer of silica-containing adsorbents and, after adsorption, regenerating the adsorbents by removing the sorbed compounds. The relative humidity of the waste vapors is preferably less than 50% in order to achieve an effective separation by adsorption.

Abstract: A process for separating a first component comprising meta-xylene, a second component comprising a mixture of para-xylene and ortho-xylene and a third component comprising ethyl benzene from a feedstream employing an adsorbent comprising a Y-zeolite containing sodium ions at exchangeable cationic sites and a desorbent material comprising toluene which in combination have selectivities for the first, second and third components, respectively, in descending order of magnitude. The process uses a simulated-moving bed counter current flow system with an intermediate raffinate stream taken off the column at about the midpoint of the adsorption zone in addition to the usual extract and raffinate product streams.

Abstract: Unsaturated compounds are separated from liquid hydrocarbon mixtures by adsorbing the unsaturated compounds on a macroporous cation exchange resin and desorbing the unsaturated compounds with a mononuclear aromatic compound.

Abstract: A process is disclosed for separation of straight chain paraffins from a mixture of paraffinic hydrocarbons by selective adsorption on a molecular sieve followed by desorption of the straight chain paraffins with gaseous hydrogen.

Abstract: Process for the preparation of alkylbenzenes by partial chlorination of linear C.sub.9 -C.sub.15 paraffins, catalytic alkylation of benzene with the resulting mixture and fractionation by distillation of the alkylation products.At least a part of the unreacted paraffins recovered by fractionation and to be recycled to the chlorination stage is submitted, continuously or intermittently, to a purification treatment with molecular sieves.The content in undesired by-products of the alkylbenzenes can thus be maintained at negligibly low values.

Abstract: A hydrocarbon separation process which includes a novel method of fractionating the extract and raffinate streams removed from a simulated moving bed of a selective adsorbent. The extract and raffinate streams are passed into separate fractionation columns, each having a sidecut removed above the feed point. Each sidecut is stripped, with the stripper overhead vapor passing directly into the extract or raffinate column. The bottoms streams of the two sidecut strippers are combined and passed into the adsorbent bed.