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 process for treating nitrogen-containing, substantially paraffinic product derived from a Fischer-Tropsch process. The substantially paraffinic product is purified in a purification process to lower the concentration of oxygen, nitrogen, and other impurities. The nitrogen content of the purified product is monitored, and the conditions of the purification step are adjusted to increase nitrogen removal if the nitrogen content of the purified product exceeds a preselected value.

Abstract: A process of reducing the sulfur content of gasoline product comprising at least three concurrent steps: a) passing input fluid comprising pollutant through at least one adsorber to produce a polluted adsorber and a purified fluid stream which leaves the adsorber, stopping the flow into said adsorber to leave residual fluid therein, and separating said residual fluid therein said adsorber to leave the polluted adsorber of reduced residual fluid content, b) heating a polluted adsorber with a heated regeneration gas to produce a hot adsorber and cooler regeneration gas, c) contacting a heated adsorber with a regeneration gas (of a lower temperature than that of said adsorber) to produce a cooler adsorber and a warmer regeneration gas, which gas is further heated to produce said heated regeneration gas which is pass to step b), said process comprising at least 3 adsorber, at least one of which being subjected to step a) at least one different adsorber to step b) and at least one further different adsorber being

Abstract: The present invention relates to agglomerated zeolitic adsorbents based on zeolite X with an Si/Al ratio such that 1.15<Si/Al?1.5, at least 90% of the exchangeable cationic sites of the zeolite X of which are occupied either by barium ions alone or by barium ions and potassium ions whose Dubinin volume is greater than or equal to 0.240 cm3/g. They are obtained by agglomerating zeolite powder with a binder, followed by the zeolitization of the binder, the exchange of the ions of the zeolite by barium ions (and potassium ions) and the activation of the adsorbents thus exchanged. These adsorbents are particularly suited to the adsorption of the para-xylene present in C8 aromatic hydrocarbon fractions in the liquid phase in processes of simulated moving bed type but also to the separation of sugars, polyhydric alcohols, cresols or substituted toluene isomers.

Abstract: A process for eliminating mercury and possibly arsenic from a hydrocarbon feed comprises: 1) distilling the hydrocarbon feed to obtain at least one light cut and at least one heavy cut; 2) treating at least one said heavy cut, said treatment comprising two steps a first step bringing said heavy cut into contact with hydrogen and a catalyst; a second step consisting of passing the effluent from the first step over a mass for capturing mercury and possibly arsenic.

Abstract: A process for adsorptive desulfurization of gasoline or diesel oil or aromatics lower than C12 containing organic sulfide impurities, wherein these feedstocks contact an amorphous alloy adsorbent comprising nickel as a major active component in a fluidized bed reactor or a magnetic-stabilized fluidized bed reactor or a slurry bed reactor. There is only a single diffuse peak at 2?=45° in the 2? range from 20° to 80° in the X-ray diffraction (XRD) pattern of the adsorbent. The adsorbent consists of 50-95 wt % of nickel, 1-30 wt % of aluminum, 0-35 wt % of iron, and 0-10 wt % of one or more metals selected from copper, zinc, molybdenum, chromium, and cobalt.

Abstract: An adsorbent for removing sulfur compounds from sulfur compounds-containing fuel gas contains a zeolite ion-exchanged with Ag and has an excellent performance when used to remove sulfur compounds from the fuel gas, irrespective of the moisture concentration in the fuel gas, and a method for removing sulfur compounds from sulfur compounds-containing fuel gas by use of an adsorbent of the above-mentioned type. The zeolite is a Na—+Y type zeolite.

Abstract: There is provided with a process for separating normal paraffins from hydrocarbons of C5-10 using zeolite molecular sieve 5A, which comprises the steps of (a) selective adsorption (b) cocurrent purge (c) countercurrent desorption. The present process employs butane for purge and desorption step to achieve excellent desorption efficiency and recycles butane in liquid phase to reduce the investment cost. The optimum operating conditions for feedstock change and adsorption capacity reduction are determined by NIR system for on-line monitoring and control. The separated normal paraffins can be efficiently applied to raw material for ethylene production and the separated non-normal paraffins can be efficiently applied to raw material for aromatic hydrocarbons production.

Abstract: This invention is directed to a method of removing dimethyl ether from an olefin stream. The method includes distilling the olefin stream so that the dimethyl ether is separated out of the olefin stream with propane. The olefin stream can then be further distilled to provide a polymer grade ethylene stream and a polymer grade propylene stream, with each stream containing not greater than about 10 wppm dimethyl ether.

Abstract: The invention comprises a process for removal of carbonyl sulfide from a hydrocarbon, which comprises contacting a hydrocarbon stream containing carbonyl sulfide with an adsorbent and then regenerating the adsorbent by passing a heated gas, containing a hydrolyzing agent. The adsorbent that is regenerated by using this process retains at least 70% of its capacity for adsorption of sulfur as compared to fresh adsorbent.

Abstract: Disclosed are compositions comprising one or more pentamantanes. Specifically disclosed are compositions comprising 10 to 100 weight percent of one or more pentamantanes. Also disclosed are novel processes for the separation and isolation of pentamantane components into recoverable fractions from a feedstock containing at least a higher diamondoid component which contains one or more pentamantane components.

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: Compounds and methods for sorbing organosulfur compounds from fluids are provided. Generally, compounds according to the present invention comprise mesoporous, nanocrystalline metal oxides. Preferred metal oxide compounds either exhibit soft Lewis acid properties or are impregnated with a material exhibiting soft Lewis acid properties. Methods according to the invention comprise contacting a fluid containing organosulfur contaminants with a mesoporous, nanocrystalline metal oxide. In a preferred embodiment, nanocrystalline metal oxide particles are formed into pellets (14) and placed inside a fuel filter housing (12) for removing organosulfur contaminants from a hydrocarbon fuel stream.

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: 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: For producing a gasoline stock with a high octane number, employed are at least one hydroisomerisation section and at least one section for adsorptively separating multibranched paraffins contained in a constituted by a C5 to C8 cut. The separation section contains at least one zeloitic adsorbent with a mixed structure with principal channels with openings defined by a ring containing 10 oxygen atoms and secondary channels with openings 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.

Abstract: A process and an apparatus for the preparation of petroleum hydrocarbon solvent with improved color stability from crude oils having high concentration of nitrogenous compounds which comprises passing said petroleum hydrocarbon stream containing substantial amount of nitrogenous compounds over a column of molecular sieves modified clays at ambient to elevated temperature and pressure maintaining the feed in the liquid state, thereby obtaining the petroleum hydrocarbon stream with desired color stability.

Abstract: A method and apparatus (101) for the recovery of fat soluble compounds, such as beta carotene, is described. In one embodiment of the invention a solution (102) containing a fat soluble compound is passed through a fluidised bed (104) of crystalline metallic ore particles, such as magnetite, allowing the fat soluble compound to bind to the particles to form a complex (109). The fat soluble compound is released from the complex (109) by passing a wash solution (107) through the fluidised bed and subsequently collected in solution (108). The crystalline metallic ore particles may be reused.

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: A process for the separation or concentration of olefinic hydrocarbons from mixtures of olefinic and paraffinic hydrocarbons uses a polyimide membrane. The process is well suited to separating propylene from propylene/propane mixtures. The novel method The membrane exhibits good resistance to plasticization by hydrocarbon components in the gas mixture under practical industrial process conditions.

Abstract: The invention includes a compositon of matter comprising a heavy oil having dispersed therein surface modified solid wherein said surface modified solids comprise solids having adsorbed thereon air oxidized polar hydrocarbons from said heavy oil and wherein said surface modified solids have a diameter of about 10 microns or less and a method for preparing the same.

Abstract: A process for the removal of trace metals from a hydrocarbon stream includes contacting the hydrocarbon stream with an absorbent material comprising antimony pentoxide supported on an absorbent substrate. The hydrocarbon product is then withdrawn from the absorbent material to provide a purified product in which 99.5 wt. % of the trace metal has been removed. Preparation of the antimony pentoxide-promoted absorbent entails treating a particulate porous substrate with an aqueous solution of antimony pentoxide. The absorbent substrate has an average particle size within the range of 1-5 mm and an average pore volume within the range of 0.7-0.85 cubic centimeters per gram. At least 80% of the surface area of the support is contained within the internal pore volume of the absorbent. The absorbent support is contacted with the antimony pentoxide solution.

Abstract: A process is described for removing polar compounds from an aromatic feedstock which contains polar compounds. The process comprises contacting the feedstock in an adsorption zone at a temperature of less than or equal to 130° C. with an adsorbent selective for the adsorption of said polar compounds and comprising a molecular sieve having surface cavities with cross-sectional dimensions greater than 5.6 Angstroms. A treated feedstock substantially free of said polar compounds can then be fed to an alkylation zone for contact under liquid phase alkylation conditions with an alkylating agent in the presence of an alkylation catalyst.

Abstract: A chemical treatment is disclosed for reducing the sulfur content of catalytically processed gasoline and intermediate crude-oil products, by absorbing the sulfur contained in such catalytically processed products on silica gel packed in a filter or assembly of filters, operating at the normal exit pressure from production of catalytically processed gasoline and distillation of intermediate crude-oil products.

Abstract: A hydrocarbon gas such as methane and LPG is desulfurized in the presence of oxygen and an oxidation catalyst to convert sulfur compounds in the gas to sulfur oxides. The sulfur oxides are then trapped downstream of the oxidation by an adsorbent. The amount of oxygen added to the hydrocarbon gas to promote oxidation is such that the sulfur compounds are selectively oxidized and the oxidation of the hydrocarbon gas is minimized to reduce hydrogen formation.

Abstract: A method for removing at least one contaminant selected from the group consisting of H2S and CO2 from contaminating streams, including the steps of providing an above ground stream comprising hydrocarbon containing the at least one contaminant, and positioning metal-containing nanoparticles having a particle size of less than or equal to about 100 nm in the stream, the metal-containing nanoparticles being selected from the group consisting of metal oxides, metal hydroxides and combinations thereof, whereby the nanoparticles adsorb the contaminants from the stream.

Abstract: In a process for separating propylene from a mixture comprising propylene and propane, the mixture is passed through a bed of an adsorbent comprising a porous crystalline material having (i) a diffusion time constant for propylene of at least 0.1 sec−1, when measured at a temperature of 373° K and a propylene partial pressure of 8 kPa, and (ii) a diffusion time constant for propane, when measured at a temperature of 373° K and a propane partial pressure of 8 kPa, less than 0.02 of said diffusion time constant for propylene. The bed preferentially adsorbs propylene from the mixture. The adsorbed propylene is then desorbed from the bed either by lowering the pressure or raising the temperature of the bed.

Abstract: A method for concentrating 2,6-dimethylnaphthalene in a dimethylnaphthalene isomer mixture includes supplying the dimethylnaphthalene isomer mixture to an adsorption column packed with Y-type zeolite. In this instance, by setting the value derived from the expression (u1/3/&egr;)d−5/3 at 14 (m5/3 s−1/3 kg−1) or more, the concentration ratio of 2,6-dimethylnaphthalene to 2,7-dimethylnaphthalene can be 2.0 or more. u here represents the linear velocity (m/s) of the dimethylnaphthalene isomer mixture supplied to an adsorption column, &egr; represents the packing density (kg/m3) of Y-type zeolite, and d represents the grain size (m) of the Y-type zeolite.

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: 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 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: 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 method for separating p-xylene by separating and recovering only p-xylene from a p-xylene-containing raw material mixture under high-temperature and high-pressure conditions using a zeolite membrane as a separating membrane is provided. The p-xylene partial pressure at the raw material side of the separating membrane is kept at a sufficiently high pressure and the p-xylene partial pressure at the recovery side of the separating membrane is controlled at a pressure which is not higher than the inflection point of p-xylene adsorption curve. This method for separating p-xylene using a zeolite membrane as a separating membrane can secure a sufficient p-xylene permeation amount and has industrial applicability.

Abstract: A process for treating nitrogen-containing, substantially paraffinic product derived from a Fischer-Tropsch process. The substantially paraffinic product is purified in a purification process to lower the concentration of oxygen, nitrogen, and other impurities. The nitrogen content of the purified product is monitored, and the conditions of the purification step are adjusted to increase nitrogen removal if the nitrogen content of the purified product exceeds a preselected value.

Abstract: While contacting under regeneration conditions an oxygen-containing stream with a sorbent comprising a promoter metal and zinc sulfide which has been sulfurized by contact with sulfur-containing hydrocarbons such as cracked-gasolines and diesel fuel, the oxygen partial pressure is controlled in a range of 0.5 to 2.0 psig to minimize sulfation of the sorbent.

Abstract: A process for treating organic compounds includes providing a composition which includes a substantially mesoporous structure of silica containing at least 97% by volume of pores having a pore size ranging from about 15 Å to about 30 Å and having a micropore volume of at least about 0.01 cc/g, wherein the mesoporous structure has incorporated therewith at least about 0.02% by weight of at least one catalytically and/or chemically active heteroatom selected from the group consisting of Al, Ti, V, Cr, Zn, Fe, Sn, Mo, Ga, Ni, Co, In, Zr, Mn, Cu, Mg, Pd, Pt and W, and the catalyst has an X-ray diffraction pattern with one peak at 0.3° to about 3.5° at 2&thgr;.

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: 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-sulfurized and comprises a support and lead oxide. The support, for example alumina, or said mass preferably has a specific surface area in the range 10 to 300 m2/g, a total pore volume in the range 0.2 to 1.2 cm3/g and a macroporous volume in the range 0.1 to 0.5 cm3/g. The lead content of said mass, expressed as lead oxide, is preferably in the range of 5% to 50% by weight. The fraction of the sulfurized mass preferably represents at least {fraction (1/20)}th of the total volume of the absorption mass.

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° C. under conditions to react the carbonyls to form reaction products which are deposited onto the catalyst.

Abstract: The present invention is a process for producing phenyl-alkanes by paraffin adsorptive separation followed by paraffin dehydrogenation and then by alkylation of a phenyl compound by a lightly branched olefin. The adsorptive separation step employs a silicalite adsorbent and, as the desorbent, a C5-C8 linear paraffin, a C5-C8 cycloparaffin, a branched paraffin such as isooctane, or mixtures thereof. The effluent of the alkylation zone comprises paraffins that are recycled to the adsorptive separation step or to the dehydrogenation step. This invention is also a process that sulfonates phenyl-alkanes having lightly branched aliphatic alkyl groups that to produce modified alkylbenzene sulfonates. In addition, this invention is the compositions produced by these processes, which can be used as detergents having improved cleaning effectiveness in hard and/or cold water while also having biodegradability comparable to that of linear alkylbenzene sulfonates, as lubricants, and as lubricant additives.

Abstract: A process is described for removing polar compounds from an aromatic feedstock which contains polar compounds and which is then used in an alkylation process. The process comprises contacting the feedstock in an adsorption zone at a temperature of less than or equal to 130° C. with an adsorbent selective for the adsorption of said polar compounds and comprising a molecular sieve having pores and/or surface cavities with cross-sectional dimensions greater than 5.6 Angstroms. A treated feedstock substantially free of said polar compounds is withdrawn from the adsorption zone and fed to an alkylation zone for contact under liquid phase alkylation conditions with an alkylating agent in the presence of an alkylation catalyst.

Abstract: CuY and AgY zeolites as selective sorbents for desulfurization of liquid fuels. Thiophene and benzene were used as the model system, and vapor phase isotherms were measured. Compared with NaY, CuY and AgY adsorbed significantly larger amounts of both thiophene and benzene at low pressures. It is hypothesized that this is due to &pgr;-complexation with Cu+ and Ag+. On a per-cation basis, more thiophene was adsorbed by Cu+ than by Ag+, eg. 0.92 molecule/Cu+ versus 0.42 molecule/Ag+ at 2×10−5 atm and 120° C. Molecular orbital calculations confirmed the relative strengths of &pgr;-complexation: thiophene>benzene and Cu+>Ag+. The experimental heats of adsorption for &pgr;-complexation are in qualitative agreement with theoretical predictions. The invention further comprises a process and sorbents for removal of aromatics from hydrocarbons.

Abstract: A process for removing polar compounds from an aromatic feedstock containing polar compounds comprising the steps of:

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: An improved process for separating hydrogen from hydrocarbons. The process includes a pressure swing adsorption step, a compression/cooling step and a membrane separation step. The membrane step uses a rubbery polymeric membrane selective for all C1-C6 hydrocarbons over hydrogen. The process can produce three products: a high-purity hydrogen stream, an LPG stream and a light hydrocarbon fuel gas stream.

Abstract: A process for removing sulfur compounds from hydrocarbon feedstreams, particularly those boiling in the naphtha range, by contacting the feedstream with an adsorbent comprised of cobalt and one or more Group VI metals selected from molybdenum and tungsten on a refractory support. This invention also relates to a process wherein a naphtha feedstream is first subjected to selective hydrodesulfurization to remove sulfur but not appreciably saturate olefins. A product stream is produced containing mercaptans that are removed by use of the cobalt-containing adsorbents of the present invention.

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 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