Abstract: A process for recovering butadiene from a C4 fraction is disclosed. The process may include: contacting a mixed C4 stream comprising butane, butene, and butadiene, with a solvent comprising an organic solvent and water in a butadiene pre-absorber column to recover an overheads fraction comprising at least a portion of the butane, butene, and water, and a first bottoms fraction comprising the organic solvent, butadiene, and at least a portion of the butene; and feeding the first bottoms fraction to a butadiene extraction unit to recover a butene fraction, a crude butadiene fraction, and a solvent fraction.

Abstract: A process for recovering butadiene from a C4 fraction is disclosed. The process may include: contacting a mixed C4 stream comprising butane, butene, and butadiene, with a solvent comprising an organic solvent and water in a butadiene pre-absorber column to recover an overheads fraction comprising at least a portion of the butane, butene, and water, and a first bottoms fraction comprising the organic solvent, butadiene, and at least a portion of the butene; and feeding the first bottoms fraction to a butadiene extraction unit to recover a butene fraction, a crude butadiene fraction, and a solvent fraction.

Abstract: A process is presented for the purification of 1,3 butadiene. The process is for treating a butadiene stream from an oxidative dehydrogenation unit, where a butane stream is dehydrogenated, generating a butadiene rich stream. The butadiene rich stream is fractionated and passed through a butadiene recovery unit. Additional C4 compounds recovered from the fractionation bottoms stream are further processed for increasing yields of butadiene.

Abstract: Methods and apparatus for the purification of isoprene, such as the purification of a bioisoprene composition from fermentor off-gas. The apparatus includes two columns that process the fermentor off-gas, which includes isoprene and various impurities. A solvent is added to the off-gas in the first column, and the isoprene is stripped from the solvent in the second column. Also provided is a downstream further purification process. Also provided are the resulting purified isoprene compositions.

Abstract: Mixtures of hydrocarbons predominantly having 4 carbon atoms per molecule known as C4 cuts are used in obtaining crude 1,3-butadiene by a thermal cracking process. Vaporous purified crude C4 cuts are produced from liquid crude C4 cuts, containing butanes, butenes, 1,3-butadiene, C3 hydrocarbons, C4 oligomers and polymers, and C5+ hydrocarbons via an extractive distillation by fist removing the C4 oligomers and polymers and the C5+ hydrocarbons and then vaporizing the liquid crude C4 cut in a vaporizer vessel. The vaporizer vessel is directly or indirectly in contact with a stripping column where liquid C4 cuts are supplied to the upper region, direct gas and liquid exchange with the vaporizer vessel occurs in the lower region, and vaporous purified crude C4 cuts are removed from the top region.

Abstract: A process for recovering 1,3-butadiene from a C4 fraction, where the butadiene extraction processes may be operated at an intermediate pressure using a liquid ring type compressor. The use of a liquid ring compressor, among other process options presented herein, may advantageously reduce capital and operating costs, similar to the compressorless option, while mitigating the risks associated with the higher operating temperatures and pressures associated with the compressorless option. Thus, the embodiments of the processes disclosed herein encompass the best features of the conventional design (low pressure, with a compressor) with the advantages of the compressorless design (low capital and operating cost), as well as other advantages unique to the systems disclosed herein.

Abstract: A butadiene extraction processes designed for flexible operations, with or without a compressor, is disclosed. The ability to run at both high and low pressures provides added process flexibility.

Abstract: A process for recovering butadiene from a C4 fraction is disclosed. The process may include: contacting a mixed C4 stream comprising butane, butene, and butadiene, with a solvent comprising an organic solvent and water in a butadiene pre-absorber column to recover an overheads fraction comprising at least a portion of the butane, butene, and water, and a first bottoms fraction comprising the organic solvent, butadiene, and at least a portion of the butene; and feeding the first bottoms fraction to a butadiene extraction unit to recover a butene fraction, a crude butadiene fraction, and a solvent fraction.

Abstract: Solvent regeneration to recover a polar hydrocarbon (HC) selective solvent substantially free of hydrocarbons (HCs) and other impurities from a solvent-rich stream containing selective solvent, heavy HCs, and polymeric materials (PMs) generated from reactions among thermally decomposed or oxidized solvent, heavy HCs, and additives is provided. A combination of displacement agent and associated co-displacement agent squeezes out the heavy HCs and PMs from the extractive solvent within a solvent clean-up zone. Simultaneously, a filter equipped with a magnetic field is positioned in a lean solvent circulation line to remove paramagnetic contaminants. The presence of the co-displacement agent significantly enhances the capability of the displacement agent in removing the heavy HCs and PMs from the extractive solvent.

Abstract: Secondary streams in 1,3-butadiene processing plants still contain high amounts of valuable 1,3-butadiene. An energy-efficient process for purifying a recycle stream from a 1,3-butadiene processing plant is provided. The recycle stream is divided into two substreams: the first substream for prepurifying pure 1,3-butadiene feedstream by removing high boilers relative to 1,3-butadiene in a stripping column and the second substream in an extractive distillation plant.

Abstract: Methods and apparatus for the purification of isoprene, such as the purification of a bioisoprene composition from fermentor off-gas. The apparatus includes two columns that process the fermentor off-gas, which includes isoprene and various impurities. A solvent is added to the off-gas in the first column, and the isoprene is stripped from the solvent in the second column. Also provided is a downstream further purification process. Also provided are the resulting purified isoprene compositions.

Abstract: The present invention relates to a process for the separation by distillation of a hydrocarbon-containing feed stream containing olefin monomer, co-monomer and hydrocarbon diluent. The present invention also relates to a distillation system including a distillation column for carrying out the process according to the invention.

Abstract: Secondary streams in 1,3-butadiene processing plants still contain high amounts of valuable 1,3-butadiene. An energy-efficient process for purifying a recycle stream from a 1,3-butadiene processing plant is provided. The recycle stream is divided into two substreams: the first substream for prepurifying pure 1,3-butadiene feedstream by removing high boilers relative to 1,3-butadiene in a stripping column and the second substream in an extractive distillation plant.

Abstract: A method for producing isoprene comprising an aqueous medium including genetically modified host cells capable of producing isoprene, where the resulting isoprene composition is processed through at least one separation and/or purification process to provide an isoprene enriched composition and a system for doing the same.

Abstract: Mixtures of hydrocarbons predominantly having 4 carbon atoms per molecule known as C4 cuts are used in obtaining crude 1,3-butadiene by a thermal cracking process. Vaporous purified crude C4 cuts are produced from liquid crude C4 cuts, containing butanes, butenes, 1,3-butadiene, C3 hydrocarbons, C4 oligomers and polymers, and C5+ hydrocarbons via an extractive distillation by fist removing the C4 oligomers and polymers and the C5+ hydrocarbons and then vaporizing the liquid crude C4 cut in a vaporizer vessel. The vaporizer vessel is directly or indirectly in contact with a stripping column where liquid C4 cuts are supplied to the upper region, direct gas and liquid exchange with the vaporizer vessel occurs in the lower region, and vaporous purified crude C4 cuts are removed from the top region.

Abstract: The invention relates to a process for workup of a stream (1) comprising butene and/or butadiene, butane, hydrogen and/or nitrogen and carbon dioxide, comprising: (a) absorption of stream (1) with a mixture (5) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to obtain a stream (9) comprising N-methylpyrrolidone, water, butene and/or butadiene, butane, and optionally carbon dioxide, and a stream (7) comprising hydrogen and/or nitrogen and butane, (b) extractive distillation of stream (9) with a stream (13) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to separate the stream (9) into a stream (17) comprising N-methylpyrrolidone, water, butene and/or butadiene, and a stream (15) comprising essentially butane, and optionally carbon dioxide, (c) distillation of stream (17) into a stream (23) comprising essentially N-methylpyrrolidone and water, and a stream (21) comprising butene and/or butadiene.

Abstract: A process is proposed for distillatively obtaining pure 1,3-butadiene from crude 1,3-butadiene in a plant comprising one or more distillation columns, comprising supply of a feed stream of crude 1,3-butadiene to the one distillation column or the first of the plurality of distillation columns, the one distillation column or the plurality of distillation columns having a flange with an internal diameter of ?80 mm, comprising two mutually opposite plane-parallel surfaces (1) with an intermediate seal (2) which seals the interior of the one distillation column or of the first of the plurality of distillation columns from an intermediate space (3) on the atmosphere side between the two mutually opposite plane-parallel surfaces (1), and the intermediate space (3) on the atmosphere side between the two mutually opposite plane-parallel surfaces (1) being closed off from the atmosphere to form a chamber, wherein the chamber is purged continuously during the operation of the plant with a low-oxygen gas or a low-oxygen

Abstract: A method for producing isoprene comprising an aqueous medium including genetically modified host cells capable of producing isoprene, where the resulting isoprene composition is processed through at least one separation and/or purification process to provide an isoprene enriched composition and a system for doing the same.

Abstract: The present invention provides a method and reactor system for hydrogenating acetylenes present in the olefin stream derived from the following streams, alone or in combination: petroleum catalytic cracking process and/or oxygenate-to-olefin reactor, such as methanol-to-olefin (MTO) reactor, in an olefin production plant before the distillation steps, wherein the acetylene hydrogenation occurs before or just after the acid gas removal step.

Abstract: The invention relates to a process for workup of a stream (1) comprising butene and/or butadiene, butane, hydrogen and/or nitrogen and carbon dioxide, comprising: (a) absorption of stream (1) with a mixture (5) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to obtain a stream (9) comprising N-methylpyrrolidone, water, butene and/or butadiene, butane, and optionally carbon dioxide, and a stream (7) comprising hydrogen and/or nitrogen and butane, (b) extractive distillation of stream (9) with a stream (13) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to separate the stream (9) into a stream (17) comprising N-methylpyrrolidone, water, butene and/or butadiene, and a stream (15) comprising essentially butane, and optionally carbon dioxide, (c) distillation of stream (17) into a stream (23) comprising essentially N-methylpyrrolidone and water, and a stream (21) comprising butene and/or butadiene.

Abstract: High purity 1,3 butadiene is recovered from a C4 fraction containing butadienes, butenes, butanes, and acetylenes that is generated from a steam cracker by extractive distillation operating with no reflux or greatly reduced reflux conditions. This no reflux (or minimum reflux) technique is generally applicable to any butadiene recovery process in which at least one extractive distillation column (EDC) is used to separate 1,3 butadiene from other C4 components in the mixture. For an ED process with two EDCs, significant reductions in total energy requirements in the both EDCs can be achieved by appropriate reductions in the reflux in each column. The performances of both EDCs are unaffected even when operating at no reflux.

Abstract: A method for the solvent extraction of 1,3-butadiene from a mixture of C4 hydrocarbons that employs a distillation tower to produce the desired 1,3-butadiene product as an overhead and a separate bottoms stream that is removed from and not recycled in the solvent extraction process.

Abstract: This invention presents a process of butadiene-1,3 extraction. The process consists of the procedure of 1st extractive fractionation, 2nd extractive fractionation, distillation and alkyne fractionation. This invention can improve the yield and capacity of butadiene extraction unit by adding an alkyne fractionator to the existing butadiene extraction unit and appropriately adjusting the process condition of 1st and 2nd extractive fractionators. This invention can decrease the energy and material consumption per unit of butadiene-1,3, which greatly improved the economic profit. The investment on various scales of butadiene extraction units for adding alkyne fractionator is almost same. Further more, the profit is in direct proportion with the scale of a plant and output is in several to some dozens of folds to investment. After the implementation of this invention, the discharge of vinyl acetylene offgas can be reduced by around 3400 tons per year, which mitigate the pollution on environment and save energy.

Abstract: The invention concerns a process and apparatus for treating a feed comprising ethylenic and acetylenic compounds. In the process of the invention, the feed is sent to a distillation step, a C4 cut and a C5+ cut are recovered, a drawn fraction comprising acetylenic compounds is treated in at least one hydrogenation step, and an effluent which is depleted in acetylenic compounds is recycled. The distillation step comprises: an initial step for pre-fractionating the feed, carried out in a pre-fractionation zone included in a distillation column; and at least one complementary fractionation step, carried out in a zone which comprises a portion A, which is distinct from and not adjacent to the portion B of the pre-fractionation zone below the supply, in which the fraction drawn from a point in A is recovered with a C4/C5+ ratio that is higher than that of the feed.

Abstract: A method for the solvent extraction of 1,3-butadiene from a mixture of C4 hydrocarbons that employs a distillation tower to produce the desired 1,3-butadiene product as an overhead and a separate bottoms stream that is removed from and not recycled in the solvent extraction process.

Abstract: A method for reducing corrosion in a diolefin extractive distillation process comprising preventing the formation of ammonium carbonate by promoting the formation of a carbonate salt that does not dissociate in the ammonium carbonate dissociation temperature range of that extractive distillation process.

Abstract: A method for reducing corrosion in a diolefin extractive distillation process comprising preventing the formation of ammonium carbonate by promoting the formation of a carbonate salt that does not dissociate in the ammonium carbonate dissociation temperature range of that extractive distillation process.

Abstract: A process for recovering crude 1,3-butadiene from a C4 fraction by extractive distillation using a selective solvent in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column to form a first subregion (A), a second subregion (B) and a lower common column region (C) and which is preceded by an extractive scrubbing column (K), wherein the operation of the dividing wall column (TK) is set by regulation of the energy input into the dividing wall column (TK) via a bottom vaporizer (V) and setting of the number of the theoretical plates in the lower common column region (C) so that a bottom stream (17) consisting of purified solvent is obtained from the dividing wall column (TK), is proposed.

Abstract: This invention presents a process of butadiene-1,3 extraction. The process consists of the procedure of 1st extractive fractionation, 2nd extractive fractionation, distillation and alkyne fractionation. This invention can improve the yield and capacity of butadiene extraction unit by adding an alkyne fractionator to the existing butadiene extraction unit and appropriately adjusting the process condition of 1st and 2nd extractive fractionators. This invention can decrease the energy and material consumption per unit of butadiene-1,3, which greatly improved the economic profit. The investment on various scales of butadiene extraction units for adding alkyne fractionator is almost same. Further more, the profit is in direct proportion with the scale of a plant and output is in several to some dozens of folds to investment. After the implementation of this invention, the discharge of vinyl acetylene offgas can be reduced by around 3400 tons per year, which mitigate the pollution on environment and save energy.

Abstract: A method is disclosed for upgrading drip oil comprising subjecting the drip oil to multiple distillation steps to form a stream rich in aromatics and a separate stream rich in dicyclopentadiene.

Abstract: Extractive distillation processes whereby water-soluble extractive distillation (ED) solvents are regenerated and recovered employ improved operations of the extractive distillation column (EDC) so that polar hydrocarbons are recovered and purified from mixtures containing polar and less polar hydrocarbons and measurable amounts of hydrocarbons that are heavier than intended feedstock and/or polymers that are generated in the ED process. The improved process can effectively remove and recover the heavy hydrocarbons and/or remove polymer contaminants from the solvent in a closed solvent circulating loop through mild operating conditions with no additional process energy being expended. With the improved process, the overhead reflux of the EDC may be eliminated to further reduce energy consumption and to enhance the loading and performance within the upper portion of the EDC, especially when two liquid phases exists therein.

Abstract: An integrated process for the isolation of benzene contained within a fluid catalytically cracked naphtha is disclosed wherein a C6 fraction containing a benzene concentrate is subjected to etherification with alcohol (e.g. methanol and/or ethanol) to convert the C6 isoolefins to ethers which are separated by fractional distillation. If desired the ethers may be dissociated to the isoolefins and alcohol. The remaining material in the benzene concentrate may then be treated to remove olefins and organic sulfur compounds so that the benzene may be removed by solvent extraction. Alternatively the benzene in the remaining material may be subjected to hydrogenation.

Abstract: Sudstituted the abstract with a new abstract as follows: The invention relates to a continuous process for separation a mixture of hydrocarbons which has beenobtained by extractive distillation of C4 fraction useing a selective solvent and the hydrocarbons from the fraction C4 which are more readily soluble in the selective solvent than are the butanes and the butenes. The mixture is fed into a first distillation column in which it is separated into a steam which is taken off at the top and comprises 1,3-butadiene, propyne, possibly further low boilers and possibly water and a bottom stream comprising 1,3-butadiene, 1,2-butadiene, acetylenes and possibly further high boilers, with the proportion of 1,3-butadiene in the bottom stream from the distillatin column being regulated in such a way that it is at least sufficiently high to dilute the acetylenes to outside the range in which there is a risk of spontaneous decomposition.

Abstract: In a method for the solvent extraction of butadiene from a mixture of hydrocarbons having four carbon atoms per molecule, which method inherently produces tars, the extraction process is operated with a tar loading level, relative to the solvent employed, of no more than about 1.6 wt. %.

Abstract: The present invention relates to a process for the liquid-liquid extraction or liquid-gas extraction of mixtures of organic compounds, in which one or more components of the mixture are completely or partly extracted by means of a phase comprising at least one ionic liquid.

Abstract: A process for recovering crude 1,3-butadiene from a C4 fraction by extractive distillation using a selective solvent in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column to form a first subregion (A), a second subregion (B) and a lower common column region (C) and which is preceded by an extractive scrubbing column (K) is proposed.

Abstract: A process is described for obtaining from an “FCC” initial C5 fraction which is enriched with isoprene and purified and usable for the selective polymerization of isoprene. A process is also described for obtaining an isoprene homopolymer from a polymerization medium comprising isoprene and at least one methyl butene, such as said “FCC” C5 fraction which is enriched with isoprene and purified. The process of obtaining the final fraction from the initial C5 fraction includes: a catalytic hydrogenation reaction of said initial C5 fraction by a palladium-based catalyst, which produces an intermediate C5 fraction comprising n-pentenes in a mass ratio which is less than 0.

Abstract: The present invention relates to the separation of olefins, diolefins and lower aromatics from mixed streams of hydrocarbons using ionic liquids in the absence of metal compounds. The present invention eliminates the metal complexes conventionally used in such separation and thus reduces the complexity of the process.

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: Methods for separating di-olefins from mono-olefins, and olefins from non-olefins such as paraffins, oxygenates and aromatics; are provided. The methods use metal salts which complex both mono-olefins and di-olefins, but which selectively complex di-olefins in the presence of mono-olefins. The metal salts are dissolved or suspended in ionic liquids, which tend to have virtually no vapor pressure. Preferred salts are Group IB salts, more preferably silver and copper salts. A preferred silver salt is silver tetrafluoroborate. A preferred copper salt is silver CuOTf. Preferred ionic liquids are those which form stable solutions, suspensions or dispersions of the metal salts, which do not dissolve unwanted non-olefins, and which do not isomerize the mono- or di-olefins. The equivalents of the metal salt can be adjusted so that di-olefins are selectively adsorbed from mixtures of mono- and di-olefins. Alternatively, both mono- and di-olefins can be adsorbed, and the mono-olefins selectively desorbed.

Abstract: A method of separating and purifying conjugated dienes includes a step of obtaining a first bottom product by taking out a hydrocarbon mixture including conjugated diene under an environment in the presence of a polymerization inhibitor including at least one of nitrite and di-lower aklylhydroxylamine in a first extractive distillation column; a step of obtaining a second bottom product and a distillation portion by distilling the first bottom product in a first diffusion column; a step of obtaining a third bottom product by taking out the distillation portion under an environment in the presence of the polymerization inhibitor in a second extractive distillation column; a step of obtaining a fourth bottom product by distilling the third bottom product in a second diffusion column; a step of recovering the second bottom product and fourth bottom product and supplying to the first extractive distillation column and/or second extractive distillation column; a step of measuring concentration of a polymerization

Abstract: A method for removing conjugated olefins from a composition comprising contacting the composition with a Diels-Alder dienophile to convert conjugated olefins to a Diels-Alder adduct and arresting the Diels-Alder adduct. A method comprising confining a Diels-Alder dienophile to a first side of a selectively permeable barrier wherein the barrier is more permeable to conjugated olefins and less permeable to Diels-Alder dienophile and Diels-Alder adduct, and contacting a composition comprising mono-olefins and conjugated olefins with the Diels-Alder dienophile to form Diels-Alder adduct, wherein the contacting reduces the concentration of conjugated olefins in the composition. A method for removing conjugated olefins from a composition comprising bubbling the composition through a liquid comprising Diels-Alder dienophile to form a liquid comprising Diels-Alder adduct.

Abstract: A process for separating olefins from sulfur-containing hydrocarbons contained in a hydrocarbon feedstock is disclosed and includes contacting the hydrocarbon feedstock with N-hydroxyethyl pyrollidone in a contacting zone, removing at least one olefin overhead from the contacting zone, and removing at least a portion of the sulfur-containing hydrocarbons off the bottom of the contacting zone along with the N-hydroxyethyl pyrollidone.

Abstract: A process for recovering DCPD from a hydrocarbon feedstock comprising introducing the hydrocarbon feedstock to a first column, recovering an overhead stream from the first column comprising C9− hydrocarbons, recovering a bottom stream from the first column comprising C10+ hydrocarbons, feeding the bottom stream from the first column to a second column, recovering an overhead stream from the second column comprising DCPD, and recovering a bottom stream from the second column comprising fuel oil, wherein the two columns are sized and operated at defined conditions such as pressures, temperatures, reflux rates, and reboil rates.

Abstract: A process for obtaining pure 1,3-butadiene from crude 1,3-butadiene by distillation is carried out in a dividing wall column in which a dividing wall is located in the longitudinal direction of the column to form an upper common column region, a lower common column region, a feed section and an offtake section.

Abstract: A hydrocarbon feedstock containing C5 olefins, C5 diolefins, CPD, DCPD, and aromatics is processed by the steps of heating a hydrocarbon feedstock containing CPD, DCPD, C5 diolefins, benzene, toluene, and xylene in a heating zone, to dimerize CPD to DCPD, thereby forming a first effluent; separating the first effluent into a C6+ stream and a C5 diolefin stream; separating the C6+ stream into a C6-C9 stream and a C10+ stream; separating the C10+ stream into a fuel oil stream and a DCPD stream; and hydrotreating the C6-C9 stream to thereby form a BTX stream.

Abstract: Methods for separating di-olefins from mono-olefins, and olefins from non-olefins such as paraffins, oxygenates and aromatics; are provided. The methods use metal salts which complex both mono-olefins and di-olefins, but which selectively complex di-olefins in the presence of mono-olefins. The metal salts are dissolved or suspended in ionic liquids, which tend to have virtually no vapor pressure. Preferred salts are Group IB salts, more preferably silver and copper salts. A preferred silver salt is silver tetrafluoroborate. A preferred copper salt is silver CuOTf. Preferred ionic liquids are those which form stable solutions, suspensions or dispersions of the metal salts, which do not dissolve unwanted non-olefins, and which do not isomerize the mono- or di-olefins. The equivalents of the metal salt can be adjusted so that di-olefins are selectively adsorbed from mixtures of mono- and di-olefins. Alternatively, both mono- and di-olefins can be adsorbed, and the mono-olefins selectively desorbed.

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: A method for removing diethylhydroxylamine (DEHA) from butadiene streams that does not leave an excessive amount of residual contaminates in the isolated butadiene stream. The DEHA is removed from the butadiene streams by ion exchange resins, which efficiently remove DEHA from the butadiene streams without causing the accumulation of an excessive amount of residual contaminants. To prevent polymerization of the butadiene upon removal of the DEHA, tert-butylcatechol (TBC) may be added to the butadiene stream before or after DEHA removal. Fresh or spent ion exchange resins may be used. After removal from the butadiene stream, the isolated DEHA can then be easily concentrated, and disposed or recycled. A method for removing DEHA from hydrocarbon streams is also disclosed.