Abstract: This document relates to oxidative dehydrogenation catalysts that include molybdenum, vanadium, and oxygen.

Abstract: This document relates to oxidative dehydrogenation catalysts that include molybdenum, vanadium, and oxygen.

Abstract: Proposed is a process for producing ethylene wherein using a dehydrogenation of ethane a process gas containing at least ethane, ethylene and compounds having a lower boiling point than ethane and ethylene is formed, wherein using at least a part of the process gas a separation input is formed and subjected to a low-temperature separation (6) in which the separation input is cooled and in which one or more condensates are separated from the separation input, wherein the condensate(s) are at least partly subjected to a low-temperature rectification to obtain a gaseous first fraction and a liquid second fraction, wherein the gaseous first fraction contains at least the ethane and the ethylene in a lower proportion than in the separation input and the compounds having a lower boiling point than ethane and ethylene in a higher proportion than in the separation input.

Abstract: Provided in this disclosure is a process for the oxidative dehydrogenation of a lower alkane into a corresponding alkene. The process includes providing a gas stream comprising the lower alkane to a reactor; contacting, in the oxidative dehydrogenation reactor, the lower alkane with a catalyst that includes a mixed metal oxide; and providing to the last 50% of the oxidative dehydrogenation reactor a stream comprising from 0.01 vol. % to 10 vol. % of a C1-C3 alcohol.

Abstract: The invention relates to a process for producing an olefin in which a reaction input stream containing at least one paraffin, oxygen and water is formed and in which a portion of the paraffin and of the oxygen in the reaction input stream is converted into the olefin by oxidative dehydrogenation using a catalyst to obtain a process gas, wherein the process gas contains at least the unconverted portion of the paraffin and of the oxygen, the olefin and the water from the reaction input stream. It is provided that at least one parameter which indicates an activity of the catalyst is determined and that an amount of the water in the reaction input stream is adjusted on the basis of the at least one determined parameter. A corresponding plant (100) likewise forms part of the subject matter of the invention.

Abstract: A process and an apparatus for producing olefins from light alkanes. A light alkane feed is contacted with catalyst particles in each of reactors, wherein each of the reactors is a fluidized bed reactor. At least a portion of the alkane feed is converted to olefins using the catalyst particles, wherein the olefins form a part of a reactor effluent stream. The reactor effluent streams from each of the reactors are merged to form a merged effluent stream. The merged effluent stream is separated into an olefin stream and the other streams. The other streams may comprise a recycle stream and light gases.

Abstract: A process is presented for the recovery of solvent used in an alkylation process. The solvent removes heavy hydrocarbons from a C4 stream. The C4 stream is passed to an alkylation unit to generate an alkylate product. A portion of the solvent is carried over with the C4 stream and needs to be recovered to reduce the aromatics content in the C4 stream, to reduce any deleterious effects of the aromatics in downstream processing.

Abstract: A catalyst for oxidative dehydrogenation (ODH) of ethane with an empirical formula Mo—V—Te—Nb—Pd—O produced using a process comprising impregnation of the Pd component on the surface of the catalyst following a calcination step using a Pd compound free of halogens. The resulting catalyst can be used in both diluted and undiluted ODH processes and shows higher than expected activity without any loss of selectivity.

Abstract: A method for recovering olefin includes: an olefin concentrating process of supplying a part or all of an olefin-containing gas containing olefin to an olefin-containing-gas separating unit that includes a separation membrane and causing this olefin-containing gas to transmit the separation membrane so as to obtain an olefin concentrated gas reduced in concentration of a component other than olefin to 1/10 or less compared with a concentration of a component other than olefin in the olefin-containing gas; and a residual-gas combustion process of disposal of residual gas that does not transmit the separation membrane in the olefin concentrating process by burning.

Abstract: Oxidative dehydrogenation is an alternative to the energy extensive steam cracking process presently used for the production of olefins from paraffins, but has not been implemented commercially partially due to the unstable nature of hydrocarbon/oxygen mixtures, and partially due to the cost involved in the construction of new facilities. An oxidative dehydrogenation chemical complex designed to reduce costs by including integration of an oxygen separation module that also addresses safety concerns and reduces emission of greenhouse gases is described.

Abstract: The present invention relates to an integrated process to convert crude oil into petrochemical products comprising crude oil distillation, dearomatization, ring opening, and olefins synthesis, which process comprises subjecting a hydrocarbon feed to dearomatization to produce a first stream enriched in aromatic hydrocarbons and naphthenic hydrocarbons and a second stream enriched in alkanes; subjecting a stream enriched in aromatic hydrocarbons and naphthenic hydrocarbons to ring opening to produce alkanes; and subjecting refinery unit-derived alkanes produced in the process to olefins synthesis.

Abstract: A process for preparing a catalyst provided in the form of a metal oxide catalyst having at least one element selected from Mo, Te, Nb, V, Cr, Dy, Ga, Sb, Ni, Co, Pt and Ce. The catalyst is subjected to an aftertreatment to increase the proportion of the M1 phase, by contacting the catalyst with steam at a pressure below 100 bar or by contacting the catalyst with oxygen to obtain an aftertreated catalyst. The aftertreated catalyst may be used for oxidative dehydrogenation processes.

Abstract: A process is presented for quenching a process stream in a paraffin dehydrogenation process. The process comprises cooling a propane dehydrogenation stream during the hot residence time after the process stream leaves the catalytic bed reactor section. The process includes cooling and compressing the product stream, taking a portion of the product stream and passing the portion of the product stream to the mix with the process stream as it leaves the catalytic bed reactor section.

Abstract: The present invention discloses a process for producing olefins from petroleum saturated hydrocarbons. The process of the present invention comprises: contacting a preheated petroleum saturated hydrocarbons feedstock with a dehydrogenation catalyst in a dehydrogenation reaction zone of a reaction system to obtain a petroleum hydrocarbon stream containing unsaturated hydrocarbon compounds, in which the dehydrogenation reaction has a conversion rate of at least 20%; and contacting the obtained petroleum hydrocarbon stream containing the unsaturated hydrocarbon compounds with olefins cracking catalyst in an olefin cracking zone of the reaction system to obtain a product stream containing olefins with a reduced number of carbon atoms.

Abstract: Disclosed is a hydrocarbon conversion process in which an alkane component is catalytically converted in the presence of an oxygen or oxidizing component (i.e., oxidant). The hydrocarbon conversion process can be an oxidative coupling reaction, which refers to the catalytic conversion of alkane in the presence of oxidant to produce an olefin product, i.e., a composition containing C2+ olefin. Reverse-flow reactors can be used to carry out the oxidative coupling reaction.

Abstract: A process for the production of propylene from a propane rich hydrocarbon source is presented. The process converts a propane rich stream and uses less equipment and energy for the separation and production of propylene. The process uses a non-noble metal catalyst and utilizes a continuous reactor-regeneration system to keep the process on line for longer periods between maintenance.

Abstract: Disclosed is a process for the catalytic dehydrogenation of alkanes so as to form the corresponding olefins. The reaction mixture is subjected to membrane separation of hydrogen, in a separate unit. Preferably a plurality of alternating reaction and separation units is used. The process of the invention serves the purpose of reducing coke formation on the catalyst, and also of achieving a higher alkane conversion without a similar increase in coke formation. The process can also be used for the production of hydrogen.

Abstract: Processes and hydrocarbon processing apparatuses for preparing mono-olefins are provided. An exemplary process includes separating a hydrocarbon feed into a first fraction of carbon-containing compounds having less than or equal to 5 carbon atoms and a second fraction of compounds that have a lower vapor pressure than those in the first fraction. Dienes and/or acetylenes from the first fraction are selectively hydrogenated into corresponding mono-olefins. Paraffins from the first fraction are converted into corresponding mono-olefins. The converted mono-olefins are contact cooled with an impurity-containing liquid hydrocarbon stream, with the impurities in the impurity-containing liquid hydrocarbon stream having a lower vapor pressure than compounds in the first fraction. The dienes and/or acetylenes from the first fraction are selectively hydrogenated prior to converting the paraffins from the first fraction into mono-olefins and after separating the first fraction from the hydrocarbon feed.

Abstract: Processes utilizing the integration of (i) processes and the associated equipment used to purify and recover propylene from propane- and/or C4+-containing refinery hydrocarbon streams, with (ii) catalytic dehydrogenation are disclosed. This integration allows for elimination of some or all of the conventional fractionation section of the dehydrogenation process, normally used to purify propylene from unconverted propane in the reactor effluent. Significant capital and utility savings are therefore attained.

Abstract: A process for the oxidative dehydrogenation of ethane is disclosed. The process may include: contacting an ethane feed and an oxygen-containing gas in the presence of an oxidative dehydrogenation catalyst in an oxidative dehydrogenation reaction zone under conditions to oxidatively dehydrogenate at least a portion of the ethane to produce a product stream comprising ethylene, carbon oxides, water, and unreacted oxygen and ethane, wherein an oxygen concentration in the product stream is at least 0.1 mol %; contacting the product stream with an oxygen elimination catalyst in an oxygen elimination reaction zone to combust at least a portion of the oxygen; recovering from the oxygen elimination reaction zone an effluent having a reduced oxygen content; separating water from the effluent; separating carbon oxides and any non-condensable gas(es) from the ethylene and the unreacted ethane; and separating the ethylene from the unreacted ethane.

Abstract: A hydrocarbon dehydrogenation process includes providing the hydrocarbon feed to a reactor. The hydrocarbon feed includes at least one hydrocarbon selected from light paraffins, heavy paraffins, or combinations thereof. The process further includes introducing an inert diluent into the feed stream, contacting the feed stream and the inert diluent with a catalyst in the reactor, and flowing an effluent stream out of the reactor.

Abstract: Processes for using a combination of carbon dioxide and oxygen in the dehydrogenation of hydrocarbons are provided. A hydrocarbon feedstock, carbon dioxide and oxygen are fed to an oxidative dehydrogenation reactor system containing one or more catalysts that promote dehydrogenation of the hydrocarbon feedstock to produce a dehydrogenated hydrocarbon product. The processes of the present invention may be used, for example, to produce styrene monomer by dehydrogenation of ethylbenzene using carbon dioxide and oxygen as oxidants.

Abstract: The invention relates to a method for producing unsaturated hydrocarbons. According to said method, in a first step, a hydrocarbon, especially a mixture which contains alkanes, essentially no water, and can contain water vapour, is continuously guided through a first catalyst bed provided with standard dehydration conditions. Liquid water, water vapour and a gas containing oxygen are then added to the reaction mixture obtained in the first step and, in a second step, the reaction mixture obtained is then continuously guided through another catalyst bed for oxidising hydrogen and for further dehydrating hydrocarbons. The first catalyst bed can be heated and the heating in the first step is then preferably regulated in such a way that an essentially isothermic operating mode is created.

Abstract: A process for the oxidative dehydrogenation of ethane is disclosed. The process may include: contacting an ethane feed and an oxygen-containing gas in the presence of an oxidative dehydrogenation catalyst in an oxidative dehydrogenation reaction zone under conditions to oxidatively dehydrogenate at least a portion of the ethane to produce a product stream comprising ethylene, carbon oxides, water, and unreacted oxygen and ethane, wherein an oxygen concentration in the product stream is at least 0.1 mol %; contacting the product stream with an oxygen elimination catalyst in an oxygen elimination reaction zone to combust at least a portion of the oxygen; recovering from the oxygen elimination reaction zone an effluent having a reduced oxygen content; separating water from the effluent; separating carbon oxides and any non-condensable gas(es) from the ethylene and the unreacted ethane; and separating the ethylene from the unreacted ethane.

Abstract: High temperature treatment of graphite nanofibers to increase their catalytic activity. The heat treated graphite nanofiber catalysts are suitable for catalyzing chemical reactions such as oxidation, hydrogenation, oxidative-dehydrogenation, and dehydrogenation.

Abstract: A processing scheme and arrangement for enhanced olefin production involves recovering thermal energy from a reactor effluent stream resulting from the dehydrogenation of a dehydrogenatable hydrocarbon. The process involves contacting the reactor effluent stream with a circulating fluid stream in a first contact cooling zone to produce a product stream and to form a heated circulating fluid stream. Thermal energy is recovered from the heated circulating fluid stream via indirect heat exchange with a first process stream in a first heat exchange zone to form a cooled circulating fluid stream. The cooled circulating fluid stream can be subsequently cooled and at least a first portion thereof returned to the first contact cooling zone.

Abstract: The invention relates to a process for preparing propene from propane, comprising the steps: A) a feed gas stream a comprising propane is provided; B) the feed gas stream a comprising propane and an oxygenous gas stream are fed into a dehydrogenation zone and propane is subjected to a nonoxidative catalytic, autothermal dehydrogenation to propene to obtain a product gas stream b comprising propane, propene, methane, ethane, ethene, C4+ hydrocarbons, carbon monoxide, carbon dioxide, steam and hydrogen, C) the product gas stream b is cooled and steam is removed by condensation to obtain a steam-depleted product gas stream c, D) carbon dioxide is removed by gas scrubbing to obtain a carbon dioxide-depleted product gas stream d, E) the product gas stream d is cooled and a liquid hydrocarbon stream e1 comprising propane, propene, methane, ethane, ethene and C4+ hydrocarbons is removed by condensation to leave a residual gas stream e2 comprising methane, hydrogen and carbon monoxide, F) the liquid hydrocarbon stre

Abstract: The invention relates to a process for preparing propene from propane, comprising the steps: A) a feed gas stream a comprising propane is provided; B) the feed gas stream a comprising propane, if appropriate steam and if appropriate and an oxygenous gas stream are fed into a dehydrogenation zone and propane is subjected to a dehydrogenation to propene to obtain a product gas stream b comprising propane, propene, methane, ethane, ethene, nitrogen, carbon monoxide, carbon dioxide, steam, if appropriate hydrogen and if appropriate oxygen; C) the product gas stream b is cooled, if appropriate compressed and steam is removed by condensation to obtain a steam-depleted product gas stream c; D) uncondensable or low-boiling gas constituents are removed by contacting the product gas stream c with an inert absorbent and subsequently desorbing the gases dissolved in the inert absorbent to obtain a C3 hydrocarbon stream d1 and an offgas stream d2 comprising methane, ethane, ethene, nitrogen, carbon monoxide, carbon dioxid

Abstract: The invention relates to a process for preparing propene from propane, comprising the steps: A) a feed gas stream a comprising propane is provided; B) the feed gas stream a comprising propane and an oxygenous gas stream are fed into a dehydrogenation zone and propane is subjected to a nonoxidative catalytic, autothermal dehydrogenation to propene to obtain a product gas stream b comprising propane, propene, methane, ethane, ethene, nitrogen, carbon monoxide, carbon dioxide, steam and hydrogen; C) product gas stream b is cooled and steam is removed by condensation to obtain a steam-depleted product gas stream c; D) uncondensable or low-boiling gas constituents are removed by contacting product gas stream c with an inert absorbent and subsequently desorbing the gases dissolved in the inert absorbent to obtain a C3 hydrocarbon stream d1 and an offgas stream d2 comprising methane, ethane, ethene, nitrogen, carbon monoxide, carbon dioxide and hydrogen; E) the C3 hydrocarbon stream d1 is cooled and compressed to ob

Abstract: Aromatic by-products are sorbed from mono-olefin-containing feedstocks of olefins having from about 6 to 22 carbon atoms per molecule that contain aromatic by-products having from 7 to 22 carbon atoms per molecule. A benzene-containing regenerant displaces and desorbs the aromatic by-products from the sorbent and a regeneration effluent is provided. The regeneration effluent is treated in a regeneration effluent distillation system to provide a benzene-rich stream and an aromatic by-products-containing stream. The latter is subjected to benzene-forming conditions and recycled to the regeneration effluent distillation system where benzene is recovered.

Abstract: A method is disclosed a method for recovering olefins and for producing hydrogen from a refinery off-gas stream in which such stream is conventionally pretreated and separated to obtain a light ends stream that contains nitrogen, hydrogen and carbon monoxide and a heavy ends stream that contains the olefins. The light ends stream is subjected to reforming and a water gas shift reactions after addition of a natural gas stream. The addition of the natural gas increases the hydrogen recovery from the light ends and also stabilizes the hydrocarbon content in the stream to be subjected to the reforming and water gas shift reactions. The heavy ends can be further treated to recover olefins such as ethylene and propylene. The rate of natural gas addition is controlled so that the concentration of the nitrogen in a stream exiting the water gas shift reactor is less than about 5 percent by volume so that hydrogen separation from such stream becomes practical.

Abstract: Novel processes for the production of polyolefins, other polymers, and oxygenated compounds, such as polypropylene, polyethylene, polybutene-1, poly(isobutylene), polystyrene, poly(1,3-butadiene), ethylene oxide, propylene oxide, acrylonitrile, acrolein and others, within gas phase and slurry phase type reactors, from olefins produced via the catalytic dehydrogenation of corresponding paraffins and other monomers inside permeable catalytic membrane reactors or non-permeable conventional reactors. The developed processes can produce both homopolymers and copolymers depending on the operating conditions of the preceding dehydrogenation permreactor. The invented processes utilize integrated separation, recycling and re-reaction operations of the unconverted olefins, paraffins and other utilized monomers and hydrocarbon molecules.

Abstract: Long chain alcohols and acids or other similar oxygenates such as esters are produced from paraffins of similar carbon number by a process comprising paraffin dehydrogenation, carbonylation, and separation. Preferably a mixture of paraffins extending over several carbon numbers and recovered from a kerosene fraction is processed, and unconverted paraffins are recycled to a dehydrogenation zone. Alternative reaction zone configurations, catalyst systems and product recovery methods are disclosed.

Abstract: A process for producing olefins and carboxylic acids from lower alkanes using a mixed metal oxide catalytic system comprising a catalyst having the formula MoaVbAlcXdYeOz wherein: X is at least one element selected from the group consisting of W and Mn; Y is at least one element selected from the group consisting of Pd, Sb, Ca, P, Ga, Ge, Si, Mg, Nb, and K; a is 1; b is 0.01 to 0.9; c is >0 to 0.2; d is >0 to 0.5; e is >0 to 0.5; and z is an integer representing the number of oxygen atoms required to satisfy the valency of Mo, V, Al, X, and Y.

Abstract: The present invention provides methods for manufacturing olefins such as ethylene and propylene from lower alkanes, that is, methane, ethane and/or propane, by oxidative dehydrogenation at elevated pressure. The olefins are selectively recovered from unconverted lower alkane feed and reaction byproducts by using a complexation separation, such as an absorption separation that uses aqueous silver nitrate as the complexation agent. Catalysts are used that give high selectivity for oxidative dehydrogenation of lower alkanes to olefins at elevated pressure, such as a nonstoichiometric rare earth oxycarbonate catalyst.

Abstract: The olefin-hydrogen effluent vapor stream from a dehydrogenation process is separated by a cryogenic separation method utilizing a cryogenic separation system. The method does not require external refrigeration and reheats and portions an expander feed stream to extract energy and controls the warm end and cold end temperature differences in the primary heat exchanger to provide energy savings and economical operation and material use.

Abstract: A method for improving the operation of a propane-propylene splitter in a process for the dehydrogenation of propane wherein the propane is dehydrogenated to produce a stream containing propylene and trace quantities of methyl acetylene and propadiene compounds and which stream is selectively hydrogenated to selectively saturate at least a majority of the trace quantities of methyl acetylene and propadiene compounds. The resulting effluent from the selective hydrogenation zone is fractionated in a propane-propylene splitter to produce a high-purity propylene product stream, an unconverted propane stream which is introduced to the dehydrogenation zone and a small slip stream or side-cut containing methyl acetylene and propadiene compounds which is introduced into the selective hydrogenation zone.

Abstract: A method for optimizing the yield of light olefins in a process for the conversion of a heavy hydrocarbon stream to aromatics and light olefins by contacting the heavy hydrocarbon stream with a zeolite catalyst along with the controlled introduction of a paraffin stream co-feed.

Abstract: The present invention relates to a process for the production of olefins from a hydrocarbon cut, comprising a step for separating at least one paraffin contained in the hydrocarbon cut, a step for dehydrogenating the paraffin and a step for purifying the hydrogen produced during dehydrogenation, at least a part of that hydrogen being recycled to the dehydrogenation step. The invention is of particular application to the preparation of olefins containing 3 to 5 carbon atoms per molecule from a C.sub.3 to C.sub.5 hydrocarbon cut containing at least one paraffin.

Abstract: A shale oil modifier is made of a crude shale oil dehydrogenated sufficiently to attain a viscosity of between about 1200-1800 poise at 60.degree. C. The crude shale oil has sufficient basic nitrogen content so that the dehydrogenated crude shale oil exhibits non-Newtonian properties when mixed with asphalt cements. Preferably, the basic nitrogen content is about 2%-2.5% by weight. The shale oil modifier is made by a process which includes providing a crude shale oil and subjecting the crude shale oil to a two stage distillation followed by a vacuum distillation and collecting the residual fraction. The residual fraction is dehydrogenated with air until a select viscosity, preferably between about 1200-1800 poise at 60.degree. C. is obtained.

Abstract: A process for the removal of trace quantities of polynuclear aromatic compounds from the vapor effluent of a hydrocarbon dehydrogenation zone containing normally gaseous olefinic hydrocarbons, trace mononuclear aromatic compounds and trace polynuclear aromatic compounds by contacting the vapor effluent of a hydrocarbon dehydrogenation zone with a lean liquid absorption stream comprising at least one alkylated mononuclear aromatic compound to absorb at least a portion of the trace mononuclear aromatic compounds and the trace polynuclear aromatic compounds to produce a rich liquid absorption stream and a gaseous olefin-containing hydrocarbon stream having a reduced concentration of mononuclear aromatic compounds and polynuclear aromatic compounds. The rich liquid absorption stream is separated to produce a stream rich in mononuclear aromatic compounds, a stream rich in alkylated mononuclear aromatic compounds and a stream comprising polynuclear aromatic compounds.

Abstract: A process for the removal of trace quantities of polynuclear aromatic compounds from the vapor effluent of a hydrocarbon dehydrogenation zone containing normally gaseous olefinic hydrocarbons, trace mononuclear aromatic compounds and trace polynuclear aromatic compounds by contacting the hot vapor effluent of a hydrocarbon dehydrogenation zone with a cold lean liquid absorption stream to absorb at least a portion of the trace polynuclear aromatic compounds to produce a rich liquid absorption stream and a gaseous olefin-containing hydrocarbon stream having a reduced concentration of polynuclear aromatic compounds.

Abstract: A process for the management of polynuclear aromatic compounds produced in a hydrocarbon dehydrogenation zone wherein the effluent from the hydrocarbon dehydrogenation zone containing dehydrogenated hydrocarbons, dehydrogenatable hydrocarbons and trace quantities of mononuclear and polynuclear aromatic hydrocarbons is admixed with a recycle stream containing mononuclear aromatic compounds and the resulting admixture is contacted with an adsorbent to reduce the concentration of mononuclear and polynuclear aromatic compounds and to produce a stream comprising dehydrogenated hydrocarbons and dehydrogenatable hydrocarbons. An off-line spent adsorbent containing mononuclear and polynuclear aromatic compounds is contacted with a hot hydrogen-rich gas to recover at least a portion of said mononuclear and polynuclear aromatic compounds to thereby regenerate the spent adsorbent.

Abstract: A process for the management of polynuclear aromatic compounds produced in a hydrocarbon dehydrogenation zone wherein the effluent from the hydrocarbon dehydrogenation zone is contacted with an adsorbent to reduce the concentration of polynuclear aromatic compounds. The resulting dehydrogenated hydrocarbon having a reduced concentration of polynuclear aromatic compounds is reacted with methanol to produce an ether. A portion of the ether is contacted with a spent bed of adsorbent to recover at least a portion of the polynuclear aromatic compounds adsorbed thereon to thereby regenerate the adsorbent.

Abstract: A device for the catalytic dehydrogenation of a C.sub.2+ paraffinic hydrocarbon charge is applicable to the synthesis of methyl tert-butyl ether. Effluent coming from the dehydrogenation reactor and containing olefins and water is cooled in at least one heat exchanger (41), saturated with water in a column (3) and sent to a stripping column (10) where it is at least partly put in contact with a recycled aqueous liquid phase containing a solvent, preferably methanol. The compressed gaseous effluent in which the water is thereby inhibited from freezing by the methanol is cooled in a heat exchanger (13) then separated in separator (8) into olefins and into hydrogen. An aqueous liquid phase with methanol is decanted at (8) and recycled in column (10).

Abstract: A device for catalytic dehydrogenation of a C.sub.2+ paraffinic cut with an improved system for cooling the effluent is applicable, for example, to the synthesis of methyl tert-butyl ether. Liquid charge 12 is evaporated in the calandria of a heat exchanger 13 in the optional presence of at least one part recycled hydrogen 15, then optionally compressed in a compressor 14 before being pre-heated in an exchanger 41 by effluent 1 and introduced into a dehydrogenation reactor 40. The effluent cooled in the tubes of exchanger 13 can be mixed with a cryogenic phase 17 resulting from the isentropic expansion of a hydrogen-rich phase separated in a separator 8, the hydrogen optionally being recycled to the calandria of the heat exchanger. The olefins recovered with the unconverted paraffins are stabilized in a column 20.

Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the preceding dehydrogenation zone is then contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then the resulting heated stream is introduced into a subsequent dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.

Abstract: A process for the removal of trace quantities of polynuclear aromatic compounds from the vapor effluent of a hydrocarbon dehydrogenation zone containing normally gaseous olefinic hydrocarbons, trace mononuclear aromatic compounds and trace polynuclear aromatic compounds by cooling the vapor effluent to condense at least a portion thereof, up to five weight percent, by introducing the resulting cooled stream into a vapor-liquid separator to produce a vapor stream containing normally gaseous olefinic hydrocarbons and having a reduced concentration of polynuclear aromatic compounds and a liquid stream containing mononuclear and polynuclear aromatic compounds and by recovering the vapor stream comprising normally gaseous olefinic hydrocarbons having a reduced concentration of polynuclear aromatic compounds.

Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the first dehydrogenation zone is then contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then introducing the resulting heated stream into a second dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.

Abstract: A process and a device for catalytic dehydrogenation of a C.sub.2+ paraffinic cut with an improved system for cooling the effluent is applicable, for example, to the synthesis of methyl tert-butyl ether. Liquid charge 12 is evaporated in the calandria of a heat exchanger 13 in the optional presence of at least one part recycled hydrogen 15, then optionally compressed in a compressor 14 before being preheated in an exchanger 41 by effluent 1 and introduced into a dehydrogenation reactor 40. The effluent cooled in the tubes of exchanger 13 can be mixed with a cryogenic phase 17 resulting from the isentropic expansion of a hydrogen-rich phase separated in a separator 8, the hydrogen optionally being recycled to the calandria of the heat exchanger. The olefins recovered with the unconverted paraffins are stabilized in a column 20.