Abstract: An object of the present invention is to provide a gas refining apparatus which can produce a product gas with high purity and high yield at low cost and can produce a plurality of types of gas as a product gas without changing an adsorbent, and the present invention provides a gas refining apparatus (10) including a first derivation line (L3) connected to the second adsorption towers (2a, 2b) and through which the first gas flows, a second derivation line (L4) connected to the second adsorption towers (2a and 2b) and through which the second gas flows, a regeneration line (L5) connected to the first adsorption towers (1a, 1b), through which a regeneration gas for regenerating a first adsorbent in the first adsorption towers (1a, 1b) flows, and a pump (P) provided in the second derivation line (L4) and configured to desorb the second gas from a second adsorbent in the second adsorption towers (2a and 2b), and the regeneration line (L5) is connected to each of the first derivation line (L3) and the second deri

Abstract: A process is provided for increasing the recovery of high-purity hydrogen from a steam cracking process in situations where byproduct methane yield is high relative to hydrogen. After a hydrocarbon gas stream is sent through a cold box and demethanizer, a small proportion of methane is sent through a pressure swing adsorption unit separately from a gas stream that contains hydrogen to increase high-purity hydrogen recovery by about 6%.

Abstract: A process is presented for the production of butadienes. The process includes the recovery of a crude butadiene stream using adsorption separation and removes the need to compress the effluent stream from the oxidative dehydrogenation process effluent stream. The process includes an adsorption step to remove C4 compounds from the oxidative effluent stream, a desorption step to recover the adsorbed C4 compounds and a regeneration step to regenerate the adsorbent for continued use in the separation process.

Abstract: Methods and apparatuses for processing hydrocarbons are provided. In one embodiment, a method for processing hydrocarbons includes providing a stream of olefins including normal olefins and non-normal olefins. The method includes separating the normal olefins from the non-normal olefins to form a stream of normal olefins. Further, the method polymerizes the stream of normal olefins to form a stream of polymerized normal olefins. The method also includes saturating the stream of polymerized normal olefins to form a stream of normal paraffins.

Abstract: The invention relates to removal of styrene from hydrocarbon mixtures, and more particularly, removal of styrene from hydrocarbon mixtures containing higher than equilibrium paraxylene concentrations.

Abstract: A method and apparatus for concentrating and recovering ethylene from the off-gas from an apparatus which produces gasoline, propylene and the like by fluidized catalytic cracking (FCC) of heavy oils such as atmospheric residue, generated in a crude oil refining process, is provided. The method and apparatus can reduce the amount of ethylene rinse in the subsequent ethylene displacement desorption process by increasing the ethylene purity of a raw material gas and reducing the concentration of weakly adsorbing components in the raw material gas and can reduce the loss of a desorbent during a distillation process for separating the desorbent from the weakly adsorbing components. Thus, ethylene can be recovered from the off-gas from fluidized catalytic cracking of heavy oils at high concentration and low cost.

Abstract: A process is presented for the separation of iso-olefins from a hydrocarbon mixture comprising paraffins and olefins. The process includes an adsorption separation system, wherein the adsorbent is selected according to the properties of the material that is desired to be adsorbed. The process also includes a selection of a desorbent, which can comprise a mixture, to provide for an enhanced recovery of the adsorbed material and a separation of the iso-olefins from paraffins.

Abstract: A process is presented for the separation of iso-olefins from a hydrocarbon mixture comprising paraffins and olefins. The process includes an adsorption separation system, wherein the adsorbent is selected according to the properties of the material that is desired to be adsorbed. The process also includes a selection of a desorbent, which can comprise a mixture, to provide for an enhanced recovery of the adsorbed material and a separation of the iso-olefins from paraffins.

Abstract: A process according to various approaches includes flushing an intermediate transfer line between a raffinate stream transfer line and a desorbent stream transfer line away from the adsorptive separation chamber to remove residual fluid including desorbent from intermediate transfer line. The process may include directing the residual fluid flushed from the intermediate transfer line to a recycle stream to introduce the residual fluid into the adsorptive separation chamber.

Abstract: A process according to various approaches includes flushing an intermediate transfer line between a raffinate stream transfer line and a desorbent stream transfer line away from the adsorptive separation chamber to remove residual fluid including desorbent from intermediate transfer line. The process may include directing the residual fluid flushed from the intermediate transfer line to a recycle stream to introduce the residual fluid into the adsorptive separation chamber.

Abstract: A process for separating a product from a multicomponent feedstream to an adsorption apparatus or system is described. 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. In embodiments the conduits used to supply the feedstream to the apparatus or system are flushed with media of multiple grades. The improvement is a more efficient use of the desorbent. In embodiments the process achieves improvements in one or more of efficiency of adsorption separation, capacity of adsorption apparatus systems, and purity of product attainable by adsorption process.

Abstract: A method and apparatus for concentrating and recovering ethylene from the off-gas from an apparatus which produces gasoline, propylene and the like by fluidized catalytic cracking (FCC) of heavy oils such as atmospheric residue, generated in a crude oil refining process, is provided. The method and apparatus can reduce the amount of ethylene rinse in the subsequent ethylene displacement desorption process by increasing the ethylene purity of a raw material gas and reducing the concentration of weakly adsorbing components in the raw material gas and can reduce the loss of a desorbent during a distillation process for separating the desorbent from the weakly adsorbing components. Thus, ethylene can be recovered from the off-gas from fluidized catalytic cracking of heavy oils at high concentration and low cost.

Abstract: The invention concerns a device for distributing fluids which are to supply a multi-stage column having a succession of plates, each plate supporting a bed of granular solid (2) and being provided with a network for distributing said fluids constituted by substantially horizontal lines (6) having a plurality of degrees of branching from 1 to rank N, the ensemble of lines from rank P to rank N being adherent to the base plane of the plate under consideration, and the lines of the last degree of branching N communicating with mixing chambers (8) disposed immediately below said base plane.

Abstract: A process for separating a product from a multicomponent feedstream to an adsorption apparatus or system is described. 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. In embodiments the conduits used to supply the feedstream to the apparatus or system are flushed with media of multiple grades. The improvement is a more efficient use of the desorbent. In embodiments the process achieves improvements in one or more of efficiency of adsorption separation, capacity of adsorption apparatus systems, and purity of product attainable by adsorption process.

Abstract: A process for separating a product from a multicomponent feedstream to an adsorption apparatus or system is described. 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. In embodiments the conduits used to supply the feedstream to the apparatus or system are flushed with media of multiple grades. The improvement is more efficient use of the desorbent. In embodiments the process achieves improvements in one or more of efficiency of adsorption separation, capacity of adsorption apparatus systems, and purity of product attainable by adsorption process.

Abstract: The present invention relates to a process for recovering polar hydrocarbons from non-polar hydrocarbons, such as aromatics from non-aromatics, naphthenes from paraffins and isoparaffins, or olefins from paraffins and isoparaffins, in feed mixtures containing at least a measurable amount of heavier hydrocarbons. According to the invention, an improved extractive distillation (extractive-distillation) process is disclosed for recovering aromatic hydrocarbons including benzene, toluene, and xylenes from heavy (C9+) hydrocarbons. The invention also relates to an improved extractive-distillation process for recovering mainly benzene and toluene from the C6-C7 petroleum streams containing at least a measurable amount of C8+ hydrocarbons.

Abstract: Embodiments of the present invention provide, for an adsorption separation system for separating normal paraffins from a hydrocarbon feed stream, a process for switching the adsorption separation from a triple split desorbent system to a dual split desorbent system, and vice versa. Switching occurs by separating and/or introducing a second flush material in the adsorption separation system. This switching can occur during normal operations.

Abstract: A process is presented for the selective separation and recovery of large normal paraffins from a heavy kerosene boiling point fraction. The process includes passing the heavy kerosene fraction through an adsorption separation system for separating the normal paraffins from the paraffin mixture. The recovered extract and raffinate streams are mixed with a diluent made up of a lighter hydrocarbon. The subsequent diluted extract and raffinate streams are passed through first fractionation columns to separate the desorbent from the diluent and the heavier paraffins. The mixture of the diluent and heavier paraffins is passed through a second set of fractionation columns to separate the diluent and the heavier paraffins.

Abstract: This invention relates to a process for conversion of hydrocarbon feedstock, comprising the steps of (A) feeding the hydrocarbon feedstock to an adsorption unit; (B) adsorbing the hydrocarbon feedstock in the adsorption unit with a solid particulate adsorbent useful for adsorbing at least one component from the hydrocarbon feedstock under adsorption conditions; (C) withdrawing the adsorbed feedstock from the adsorption unit; (D) desorbing the component(s) from the solid particulate adsorbent; and (E) removing, under the adsorption conditions for a fractional time of step (B), at least a portion of said adsorbent while the feedstock is being fed to the adsorption unit.

Abstract: Processes and systems for removing contaminants from a paraffin containing feedstock are provided that include: providing a paraffin containing feedstock, passing the paraffin containing feedstock to an inlet of a guard bed that includes an adsorbent material, and contacting the paraffin containing feedstock with the adsorbent material in the guard bed to produce a treated paraffin containing feedstock. The processes and systems can also include removing the treated paraffin containing feedstock from an outlet of the guard bed, and passing the treated paraffin containing feedstock to a paraffin separation zone that separates normal paraffins from the treated paraffin containing feedstock.

Abstract: An as prepared Na-ETS-10 zeolite was modified by ion exchange with a mono-, di-, or tri-valent cation and mixtures thereof. Several of the modified ETS-10 zeolites showed improved pressure swing capacity during the selective adsorption of ethylene from an ethylene/ethane mixture, relative to Na-ETS-10, although the selectivity of adsorption decreased. Modification with Ba2+ and Ba2+/H+ provided modified ETS-10 zeolite adsorbents having a good balance of selectivity and pressure swing capacity for the separation of ethylene/ethane mixtures, making them useful adsorbents for PSA processes.

Abstract: An improved process for the production capacity and feedstock handling flexibility of a simulated moving bed adsorptive separation process by introducing a second feed stream to the adsorbent chamber comprising a feed material of a different concentration of the desired compound than the concentration of the desired compound in the first feed material stream. The introduction of this second feed material stream may be performed at any location on the adsorbent chamber between (i) a transfer point located immediately upstream of the point of the raffinate material stream withdrawal from the adsorbent chamber to (ii) a transfer point located immediately downstream of the point of extract material stream withdrawal from the adsorbent chamber. A recycle stream may be introduced into the system at a location having a concentration similar to the concentration of the first feed material stream.

Abstract: A process is described for the separation of a first chemical compound from a liquid feed stream comprising at least first and second chemical compounds by simulated countercurrent adsorptive separation. In the process, the feed stream and a liquid desorbent stream are passed into at least one multi-bed adsorbent chamber at two different points via different transfer lines and an extract stream rich in the first chemical compound and a raffinate stream depleted in the first chemical compound are removed from the adsorbent chamber at two different points by two additional transfer lines. In addition, the contents of the transfer line which has just been used to supply the desorbent stream are flushed into the adsorbent chamber at a point along the chamber between the transfer line just used to supply the desorbent stream and the transfer line just used to withdraw the raffinate.

Abstract: A process is presented for the selective separation and recovery of large normal paraffins from a heavy kerosene boiling point fraction. The process includes passing the heavy kerosene fraction through an adsorption separation system for separating the normal paraffins from the paraffin mixture. The recovered extract and raffinate streams are mixed with a diluent made up of a lighter hydrocarbon. The subsequent diluted extract and raffinate streams are passed through first fractionation columns to separate the desorbent from the diluent and the heavier paraffins. The mixture of the diluent and heavier paraffins is passed through a second set of fractionation columns to separate the diluent and the heavier paraffins.

Abstract: Systems and processes are provided that relate to the recovery of sorbates in processes utilizing temperature controlled adsorption. Sorbate recovery can include providing a temperature controlled adsorber that is undergoing a regeneration cycle after undergoing an adsorption cycle. The temperature controlled adsorber can have one or more adsorption flow passages and one or more heat transfer flow passages. The one or more adsorption flow passages can contain an adsorptive material coating with a sorbate adsorbed thereto. A heating fluid can be provided to the one or more heat transfer flow passages of the temperature controlled adsorber. A regeneration stream can be provided to the one or more adsorption flow passages of the temperature controlled adsorber. The adsorptive material coating can be regenerated by removing the sorbate from the temperature controlled adsorber to produce a regeneration effluent stream.

Abstract: The present invention discloses a means to improve the production capacity and feedstock handling flexibility of a simulated moving bed adsorptive separation process by introducing a second feed stream to the adsorbent chamber, such second feed stream comprising a feed material of a different concentration of the desired compound than the concentration of such desired compound in the first feed material stream. The introduction of this second feed material stream may be performed at any location on the adsorbent chamber between (i) a transfer point located immediately upstream of the point of the raffinate material stream withdrawal from the adsorbent chamber to (ii) a transfer point located immediately downstream of the point of extract material stream withdrawal from the adsorbent chamber. The specific transfer point used for the introduction of the second feed material stream will depend upon the concentration of the desired component in the second feed material stream.

Abstract: The present invention is related to a method for kinetically separating a light hydrocarbon mixture comprising at least two components by preferentially adsorbing a first component on a zeolite adsorbent comprising 8-member rings of tetrahedra as the pore opening controlling hydrocarbon diffusion and alkali metal cations balancing a framework charge, wherein a second component is not preferentially adsorbed. The novel process comprises contacting the light hydrocarbon mixture with a zeolite adsorbent having a SiO2/Al2O3 ratio greater than about 50 and less than 200 and further having a diffusion rate at least 50 times greater for the first component as compared to the second component, and then recovering at least one of the first component or the second component.

Abstract: In a process for selectively separating 1-butene from a C4 feed stream comprising at least 1-butene, cis-2-butene and trans-2-butene, the feed stream is passed through a first bed of an adsorbent comprising a crystalline microporous material to form a substantially trans-2-butene-free effluent stream. Then, the substantially trans-2-butene-free effluent stream is passed through a second bed of an adsorbent comprising a crystalline microporous material to form a substantially 1-butene-free effluent stream, whereby the 1-butene is separated from the feed stream. The adsorbed 1-butene is then typically desorbed from the second adsorbent bed either by lowering the pressure or raising the temperature of the bed.

Abstract: A novel process effective for the removal of organic sulfur compounds, organic nitrogen compounds and light olefins from liquid hydrocarbons is disclosed. The process more specifically addresses the removal of these contaminants from aromatic compounds including benzene and toluene and from naphtha. The liquid hydrocarbons are contacted with a blend of at least one metal oxide and an acidic zeolite. Preferably, the metal oxide comprises nickel oxide and molybdenum oxide and the acidic zeolite is acidic stabilized zeolite Y. This blend has a significant capacity for adsorption of impurities and can be regenerated by oxidative treatment.

Abstract: A process for separating mixtures of hydrocarbon isomers on molecular sieves, including providing columns which include molecular sieves and function alternatively as secondary adsorption, primary adsorption, and desorption devices, feeding the mixtures of hydrocarbon isomers to a column functioning as the primary adsorption device for adsorbing isomers with greater selectivity towards the molecular sieves, feeding effluent of the mixtures from the column functioning as the primary adsorption device to a column functioning as the secondary adsorption device for adsorbing remaining isomers with greater selectivity, discharging isomers with a lower selectivity from the column functioning as the secondary adsorption device and a desorbing agent therein, feeding a desorbing agent to the column functioning as the desorption device, discharging isomers with a greater selectivity towards the molecular sieves and the desorbing agent in the column functioning as the desorption device.

Abstract: Sulfur resistant/tolerant adsorbents useful for separating olefins from paraffins in a cracked gas stream including hydrogen sulfide. The method comprises the steps of contacting the gaseous mixture with an adsorbent which preferentially adsorbs the alkene, at a selected temperature and pressure, thereby producing a non-adsorbed component and an alkene-rich adsorbed component; the adsorbent comprising a carrier having a surface area, the carrier having been impregnated with a silver compound by incipient wetness, the silver compound releasably retaining the alkene; and changing at least one of the pressure and temperature to thereby release the alkene-rich component from the adsorbent. The adsorbent substantially maintains its adsorbent capacity and preference for the alkene in the presence of the sulfur compound. Sulfur resistant/tolerant adsorbents useful for selectively separating dienes from a mixture, particularly one containing mono-olefins and hydrogen sulfide, are also disclosed.

Abstract: A method for increasing removal of drag reducer additive (DRA) from liquid hydrocarbon fuel. The method comprises producing contaminated liquid hydrocarbon fuel comprising a concentration of removable DRA comprising a quantity of one or more polar groups, and contacting the contaminated liquid hydrocarbon fuel with an amount of one or more removal agents under removal conditions effective to produce a reduced concentration of the removable DRA.

Abstract: A method for improving performance of an engine comprising contacting contaminated liquid hydrocarbon fuel comprising an initial concentration of DRA with one or more effective DRA removal agent under conditions effective to produce decontaminated liquid hydrocarbon fuel comprising a reduced concentration of the DRA, and feeding the decontaminated liquid hydrocarbon fuel to the engine.

Abstract: The application relates to a method for selecting drag reducer additive (DRA) effectively removable by activated carbons and graphites to be used in fuel. The appliction also relates to effective activated carbons and graphites for removing DRA from fuel, and to a method of using effective activated carbons and graphites to remove DRA from fuel.

Abstract: Processes using heterogeneous adsorbents are disclosed for purification of olefins such as are typically produced by thermal cracking of suitable hydrocarbon feedstocks, by providing a impure mixture comprising at least one olefin of from 2 to about 8 carbon atoms, acetylenic impurities having the same or similar carbon content in an amount of up to about 1 percent by volume base upon the total amount of olefin present and optionally saturated hydrocarbon gases; admixing a source of dihydrogen with the impure mixture to form a feedstream comprising a sub-stoichiometric amount of dihydrogen based upon conversion of the total amount of acetylenic impurities present to their olefinic analogs; and passing the feedstream through a particulate bed of adsorbent comprising predominantly a support material on which is dispersed at least one metallic element in the zero valent state, to effect, under conditions suitable for adsorption within the bed, selective adsorption and/or complexing of the contained acetylenic co

Abstract: Processes using heterogeneous adsorbents are disclosed for purification of olefins such as are typically produced by thermal cracking of suitable hydrocarbon feedstocks. The processes for recovery of diene-free feedstocks includes passing an olefinic process stream containing undesirable levels of propadiene, and optionally hydrocarbon compounds having more than one double bond, small amounts of acetylenic impurities, and/or other organic components, through a particulate bed of heterogeneous adsorbent comprising a metal supported on a high surface area carrier, under conditions suitable for adsorption of dienes. Beneficially, the resulting gaseous mixtures also have reduced levels of other hydrocarbons having more than one double bond, and have reduced levels of acetylenic impurities, such as acetylene and methylacetylene.

Abstract: Processes using heterogeneous adsorbents are disclosed for purification of olefin streams, such as are produced by thermal cracking of hydrocarbons, to obtain a feedstock suitable for formation of olefin polymers. These purification processes comprises: providing an impure gaseous mixture; passing the impure mixture through a bed of regenerated adsorbent which is free of a substantial amount of carbon monoxide; effecting, in the presence of an essentially dihydrogen-free atmosphere within the bed, selective adsorption of the contained acetylenic impurities with the adsorbent until levels of the acetylenic impurities in the effluent mixture increase to a limiting level in a range downward from about 1 parts per million by volume; and thereafter regenerating the resulting bed of adsorbent in the presence of a reducing gas comprising dihydrogen which reducing gas is free of a substantial amount of carbon monoxide.

Abstract: Processes using heterogeneous adsorbents are disclosed for purification of olefins such as are typically produced by thermal cracking of suitable hydrocarbon feedstocks, by providing a impure mixture comprising at least one olefin of from 2 to about 8 carbon atoms, acetylenic impurities having the same or similar carbon content in an amount of up to about 1 percent by volume base upon the total amount of olefin present and optionally saturated hydrocarbon gases; admixing a source of dihydrogen with the impure mixture to form a feedstream comprising a sub-stoichiometric amount of dihydrogen based upon conversion of the total amount of acetylenic impurities present to their olefinic analogs; and passing the feedstream through a particulate bed of adsorbent comprising predominantly a support material on which is dispersed at least one metallic element in the zero valent state, to effect, under conditions suitable for adsorption within the bed, selective adsorption and/or complexing of the contained acetylenic co

Abstract: This invention provides a facile method for removing odor-causing species from lubricants. In this method, such species are removed by contacting the lubricant composition with at least one zeolite. Preferred zeolites include the type 13X Molecular Sieve, i.e., Na86[(AlO2)86(SiO2)106].276 H2O.

Abstract: Processes for converting C1 to C3 alkanes into high purity C6 to C24 normal alpha olefins and internal combustion engine grade fuels and/or lubricating oils comprising a sequence of fractionation and thermal cracking and/or hydrocracking operations. The C6 to C24 normal alpha olefin fractions generally have a purity of at least about 90 wt. %.

Abstract: The present invention relates to a method for separating a lactone-containing high-molecular weight compound having an alkyl group as its side chain from a lactone-containing high-molecular weight compound having an alkenyl group as its side chain by using a sulfonic acid group-containing cation exchange resin pretreated with silver ions.

Abstract: The invention provides novel adsorbents for use in the separation of unsaturated hydrocarbons from a mixture of gases containing such hydrocarbons. The preferred adsorbents comprise metal compounds supported on high surface area carriers. The adsorbents of the invention are usable in pressure swing adsorption or temperature swing adsorption processes.

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 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: 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: 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: 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: 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: 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.