Abstract: A multi-stage dehydrogenation process including contacting, in a first stage, a feed stream comprising a hydrocarbon and steam with a dehydrogenation catalyst under dehydrogenation conditions to yield a first stage effluent, heating the first stage effluent, and contacting, in a second stage, the heated first stage effluent with a dehydrogenation catalyst under dehydrogenation conditions to yield a second stage effluent comprising a dehydrogenation product, wherein the first stage includes a first reactor and a second reactor arranged in parallel, and wherein the second stage includes a third reactor connected in series with the first reactor and the second reactor. A multi-stage dehydrogenation system for carrying out dehydrogenation is also provided.

Abstract: A process for separating xylene from a feedstock in which the feedstock is separated into a xylene stream, a benzene rich stream and a light ends stream. Two separation zones may be utilized in which liquid from both is sent to a compression zone and the vapor from the compression zone is combined with a stream prior to the stream entering the second separation zone.

Abstract: The present invention is directed to reduced-energy improvements in methods and systems to produce styrene monomer via ethylbenzene dehydrogenation. The methods and systems reduce utility cost and provide savings in comparison with the current technology practiced in the industry.

Abstract: A method for improving productivity and process stability in styrene monomer manufacturing system using a reaction system having multiple reactors connected in series, which can prevent destruction of the embedded catalyst and bending of a screen which supports catalyst and achieve homogeneous catalyst inactivation during the reaction by divergence of some portions of the feed containing steam and ethylbenzene and injection thereof into a certain point of the system.

Abstract: The present invention is a process for the production of styrene monomer from ethylbenzene comprising the steps of: a) catalytically dehydrogenating said ethylbenzene in the presence of steam thereby catalytically producing a dehydrogenation effluent gas containing essentially unreacted ethylbenzene, styrene monomer, hydrogen, steam and divinylbenzene; b) quenching said effluent gas with an aqueous reflux in at least a quenching column to cool said effluent gas, and thereby obtaining a gas at the overhead and in the bottom a liquid stream warmer than the aqueous reflux; c) condensing said overhead gas thereby producing a liquid organic phase, an aqueous phase and a gaseous phase; d) using a portion or the whole of said aqueous phase of step c) as reflux for said step b) of quenching; e) sending to a decanter the liquid stream obtained at step b) to recover an aqueous phase and an organic phase.

Abstract: A process for the coupling of hydrocarbons and utilizing the heat energy produced by the reaction is disclosed. In one embodiment the process can include reacting methane with oxygen to form a product stream containing ethane and further processing the ethane to ethylene in an existing ethylene production facility while using the heat energy produced by the reaction within the facility.

Abstract: A process for preparing styrene via the catalytic dehydrogenation of ethylbenzene, comprising recirculation of reaction byproducts to the initial reaction stream as an oil based diluent, providing an effective means for reducing the steam to oil ratio required to operate the catalytic dehydrogenation reactor.

Abstract: A process for the dehydrogenation of a paraffinic hydrocarbon compound, such as an alkane or alkylaromatic hydrocarbon compound to produce an unsaturated hydrocarbon compound, such as an olefin or vinyl aromatic compound or mixture thereof, in which a dehydrogenation catalyst contacts gaseous reactant hydrocarbons in a reactor at dehydrogenation conditions.

Abstract: A supported catalyst and process for dehydrogenating a hydrocarbon, the catalyst comprising a first component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium, and compounds thereof; a second component selected from the group consisting of metals of Group 8 of the Periodic Table of the Elements and compounds thereof, and a support comprising alumina in the gamma crystalline form. The catalysts are especially active and efficient when employed in concurrent flow in a dehydrogenation reactor having an average contact time between the hydrocarbon and catalyst of from 0.5 to 10 seconds.

Abstract: A process for long-term operation of a continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, in which a reaction gas mixture stream comprising the hydrocarbon to be dehydrogenated in a molar starting amount KW is conducted through an overall catalyst bed comprising the total amount M of dehydrogenation catalyst and the deactivation of the overall catalyst bed is counteracted in such a way that, with increasing operating time, the contribution to the conversion in the first third of the total amount M of dehydrogenation catalyst in flow direction decreases, the contribution to the conversion in the last third of the total amount M of dehydrogenation catalyst in flow direction increases, and the contribution to the conversion in the second third of the total amount M of dehydrogenation catalyst in flow direction passes through a maximum.

Abstract: Disclosed is a method for removing water, nitrogen compounds, and unsaturated aliphatic compounds from a hydrocarbon feed stream by passing the hydrocarbon feed stream through a water removal zone, a nitrogen removal zone, and an unsaturated aliphatic compound removal zone. By on aspect, the method includes removing water from the hydrocarbon feed stream, contacting the feed stream with a nitrogen selective adsorbent, and contacting the feed stream with an unsaturated aliphatic compound removal material.

Abstract: Disclosed is a method for treating two or more aromatic feed streams including combining one aromatic feed stream with another aromatic feed stream. The method further includes passing the combined feed stream to a unsaturated aliphatic compound removal zone for removing an unsaturated aliphatic compound therefrom. The method further includes passing the combined aromatic feed stream to a nitrogen removal zone for removing a nitrogen compound therefrom.

Abstract: The present invention is a process for the production of styrene monomer from ethylbenzene comprising the steps of: a) catalytically dehydrogenating said ethylbenzene in the presence of steam thereby catalytically producing a dehydrogenation effluent gas containing essentially unreacted ethylbenzene, styrene monomer, hydrogen, steam and divinylbenzene; b) quenching said effluent gas with an aqueous reflux in at least a quenching column to cool said effluent gas, and thereby obtaining a gas at the overhead and in the bottom a liquid stream warmer than the aqueous reflux; c) condensing said overhead gas thereby producing a liquid organic phase, an aqueous phase and a gaseous phase; d) using a portion or the whole of said aqueous phase of step c) as reflux for said step b) of quenching; e) sending to a decanter the liquid stream obtained at step b) to recover an aqueous phase and an organic phase.

Abstract: The present invention is a process for the production of styrene monomer from ethylbenzene comprising the steps of: a) catalytically dehydrogenating said ethylbenzene in the presence of steam thereby catalytically producing a dehydrogenation effluent gas containing essentially unreacted ethylbenzene, styrene monomer, hydrogen, steam and divinylbenzene; b) quenching said effluent gas with an aqueous reflux in at least a quenching column to cool said effluent gas, and thereby obtaining a gas at the overhead and in the bottom a liquid stream warmer than the aqueous reflux; c) condensing said overhead gas thereby producing a liquid organic phase, an aqueous phase and a gaseous phase; d) using a portion or the whole of said aqueous phase of step c) as reflux for said step b) of quenching; e) sending to a decanter the liquid stream obtained at step b) to recover an aqueous phase and an organic phase.

Abstract: A process for dehydrogenation of alkylaromatic hydrocarbon, including: contacting a reactant vapor stream, comprising an alkylaromatic hydrocarbon and steam and having a first steam to alkylaromatic hydrocarbon ratio, with a dehydrogenation catalyst to form a vapor phase effluent comprising a product hydrocarbon, the steam, and unreacted alkylaromatic hydrocarbon; feeding at least a portion of the effluent to a splitter to separate the product hydrocarbon from the unreacted alkylaromatic hydrocarbon; recovered from the splitter as bottoms and overheads fractions, respectively; recovering heat from a first portion of said overheads fraction by indirect heat exchange with a mixture comprising alkylaromatic hydrocarbon and water to at least partially condense said portion and to form an azeotropic vaporization product comprising alkylaromatic vapor and steam having a second steam to alkylaromatic hydrocarbon ratio; and combining the azeotropic vaporization product with additional alkylaromatic hydrocarbon and ad

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: A process for dehydrogenation of alkylaromatic hydrocarbon, including: contacting a reactant vapor stream, comprising an alkylaromatic hydrocarbon and steam and having a first steam to alkylaromatic hydrocarbon ratio, with a dehydrogenation catalyst to form a vapor phase effluent comprising a product hydrocarbon, the steam, and unreacted alkylaromatic hydrocarbon; feeding at least a portion of the effluent to a splitter to separate the product hydrocarbon from the unreacted alkylaromatic hydrocarbon; recovered from the splitter as bottoms and overheads fractions, respectively; recovering heat from a first portion of said overheads fraction by indirect heat exchange with a mixture comprising alkylaromatic hydrocarbon and water to at least partially condense said portion and to form an azeotropic vaporization product comprising alkylaromatic vapor and steam having a second steam to alkylaromatic hydrocarbon ratio; and combining the azeotropic vaporization product with additional alkylaromatic hydrocarbon and ad

Abstract: Methods and systems for extending the life of a dehydrogenation catalyst are described herein. For example, one embodiment includes providing an alkyl aromatic hydrocarbon feed stream to a reaction chamber, contacting the feed stream with a dehydrogenation catalyst to form a vinyl aromatic hydrocarbon, the dehydrogenation catalyst including iron oxide and an alkali metal catalysis promoter and supplying a catalyst life extender to at least one reaction chamber, the reaction chamber loaded with the dehydrogenation catalyst, wherein the catalyst life extender includes a potassium salt of a carboxylic acid.

Abstract: Embodiments of methods and apparatuses for producing styrene are provided. The method comprises the steps of introducing ethylbenzene to a first dehydrogenation reactor containing a first high activity dehydrogenation catalyst at a first predetermined inlet temperature to form a first intermediate effluent stream that comprises styrene, ethylbenzene, and hydrogen. Oxygen is added to the first intermediate effluent stream to form a first oxygenated intermediate effluent stream. The first oxygenated intermediate effluent stream is introduced to a first oxidation-reheat dehydrogenation reactor at a second predetermined inlet temperature of about 530° C. or less to form styrene. The first oxidation-reheat dehydrogenation reactor contains a first oxidation catalyst and a second high activity dehydrogenation catalyst.

Abstract: Methods and processes for increasing the efficiency and/or expanding the capacity of a dehydrogenation unit by use of at least one direct heating unit are described.

Abstract: Methods of oxidative dehydrogenation are described. Surprisingly, Pd and Au alloys of Pt have been discovered to be superior for oxidative dehydrogenation in microchannels. Methods of forming these catalysts via an electroless plating methodology are also described. An apparatus design that minimizes heat transfer to the apparatus' exterior is also described.

Abstract: Dehydrogenation of a reactor system of one or more vertically oriented flow reactors equipped with a system for introducing a catalyst extender into the inlet of the reactor. A vertically oriented radial flow reactor comprises inner and outer reactor tubes having perforated wall members extending longitudily of the reactor and defining an annulus containing a dehydrogenation catalyst. A supply line to the reactor is equipped with a rotation vane. An injection nozzle comprising a coaxial flow tube extends into the supply line downstream of the vane. The coaxial flow tube has an interior chamber and an annular chamber surrounding the interior chamber and extending into the supply line along with the interior chamber. The interior chamber is connected to a catalyst extender source and the annular chamber is connected to a source of a carrier gas which is effective to disperse the extender within feedstock flowing into the reactor.

Abstract: Processes are provided for the production of styrene monomer by oxidative dehydrogenation of EB using CO2 as a soft oxidant. Carbon dioxide is used as the reaction diluent in one or more dehydrogenation reactors and to supply the heat required for the endothermic reaction of EB to styrene monomer. In the dehydrogenation reactors, two parallel reactions for styrene monomer formation occur simultaneously: (1) direct EB dehydrogenation to styrene monomer over a catalyst using heat provided by the carbon dioxide, and (2) oxidative dehydrogenation of EB with carbon dioxide to form styrene monomer.

Abstract: Improved methods and related apparatus are disclosed for efficiently recovering the heat of condensation from overhead vapor produced during separation of various components of dehydrogenation reaction effluent, particularly in ethylbenzene-to-styrene operations, by the use of at least a compressor to facilitate azeotropic vaporization of an ethylbenzene and water mixture within a preferred range of pressure/temperature conditions so as to minimize undesired polymerization reactions.

Abstract: The present invention is a process for the production of styrene monomer from ethylbenzene comprising the steps of: a) catalytically dehydrogenating said ethylbenzene in the presence of steam thereby catalytically producing a dehydrogenation effluent gas containing essentially unreacted ethylbenzene, styrene monomer, hydrogen, steam and divinylbenzene; b) quenching said effluent gas with an aqueous reflux in at least a quenching column to cool said effluent gas, and thereby obtaining a gas at the overhead and in the bottom a liquid stream warmer than the aqueous reflux; c) condensing said overhead gas thereby producing a liquid organic phase, an aqueous phase and a gaseous phase; d) using a portion or the whole of said aqueous phase of step c) as reflux for said step b) of quenching; e) sending to a decanter the liquid stream obtained at step b) to recover an aqueous phase and an organic phase.

Abstract: Methods are disclosed for the dehydrogenation of feed streams, such as in the manufacture of styrene from ethylbenzene, using a catalyst bed having catalyst with differing activities. In particular, the use of upstream and downstream catalyst beds of relatively low and high activities, respectively, can reduce the production of unwanted byproducts, especially in styrene production processes employing an oxidative reheat step (oxidation zone) prior to ethylbenzene dehydrogenation. The methods allow the maximum temperature in the oxidation zone to be decreased, thereby reducing the formation of unwanted oxygenated byproducts (e.g., phenol).

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 method and system for providing heat to a chemical conversion process is advantageously employed in the production of olefin by the catalytic dehydrogenation of a corresponding hydrocarbon. The catalytic dehydrogenation process employs diluent steam operating at a steam to oil ratio which can be 1.0 or below and relatively low steam superheater furnace temperature. The process and system are advantageously employed for the production of styrene by the catalytic dehydrogenation of ethylbenzene.

Abstract: Catalysts and methods are described for the dehydrogenation of ethylbenzene in the presence of an oxidant gas, such as oxygen or carbon dioxide, using a mixed metal oxide (MMO) catalyst or lithium-promoted sulfated zirconia catalyst to prepare styrene monomer. Ethylbenzene, steam or other inert gas, and an oxidant gas are fed to an oxydehydrogenation unit containing a MMO catalyst or lithium-promoted sulfated zirconia catalyst to produce a dehydrogenated product mixture. The dehydrogenated product mixture is cooled, off gases and condensate are separated from the mixture, and the dehydrogenated product mixture is fed to a distillation unit. Styrene monomer is distilled from the dehydrogenated product mixture.

Abstract: Process for the production of vinyl-aromatic monomers which comprises: a) feeding an aromatic stream and an olefinic stream to alkylation; b) feeding the reaction product coming from the alkylation section to a first separation section; c) recovering the mono-alkylated aromatic hydrocarbon from the first separation section; d) feeding the mono-alkylated aromatic product to a dehydrogenation section; e) cooling and condensing the reaction gases in the shell of one or more heat exchangers; f) feeding the reaction product coming from the dehydrogenation section to a second separation section; g) recovering the stream of vinyl-aromatic monomer.

Abstract: A manufacturing plant for carrying out a process for the catalytic dehydrogenation of a first unsaturated hydrocarbon to form a second unsaturated hydrocarbon which has one olefinically unsaturated bond more than the first unsaturated hydrocarbon and otherwise an unchanged carbon skeleton, which process comprises: contacting in a first step a feed comprising the first unsaturated hydrocarbon with a first dehydrogenation catalyst having a temperature parameter T1 and a selectivity parameter S1, and contacting in a second step a reaction product of the first step comprising the first unsaturated hydrocarbon and the second unsaturated hydrocarbon with a second dehydrogenation catalyst having a temperature parameter T2 and a selectivity parameter S2, such that T1<T2 and S1<S2.

Abstract: Methods and processes for reducing alkylation catalyst poisoning are described herein.

Abstract: A process for reacting feed in and an apparatus comprising a radial flow reactor including a first catalyst bed disposed between an outer wall and a centerpipe of the vessel and a second catalyst bed disposed within a centerpipe. Also disclosed is a method of loading catalyst into the radial flow reactor.

Abstract: Improved methods and related apparatus are disclosed for efficiently recovering the heat of condensation from overhead vapor produced during separation of various components of dehydrogenation reaction effluent, particularly in ethylbenzene-to-styrene operations, by the use of at least a compressor to facilitate azeotropic vaporization of an ethylbenzene and water mixture within a preferred range of pressure/temperature conditions so as to minimize undesired polymerization reactions.

Abstract: One exemplary embodiment can include a hydrocarbon conversion process. Generally, the process includes passing a hydrocarbon stream through a hydrocarbon conversion zone comprising a series of reaction zones. Typically, the hydrocarbon conversion zone includes a staggered-bypass reaction system having a first, second, third, and fourth reaction zones, which are staggered-bypass reaction zones, and a fifth reaction zone, which can be a non-staggered-bypass reaction zone, subsequent to the staggered-bypass reaction system.

Abstract: One exemplary embodiment can include a hydrocarbon conversion process. Generally, the process includes passing a hydrocarbon stream through a hydrocarbon conversion zone comprising a series of reaction zones. Typically, the hydrocarbon conversion zone includes a staggered-bypass reaction system having a first, second, third, and fourth reaction zones, which are staggered-bypass reaction zones, and a fifth reaction zone, which can be a non-staggered-bypass reaction zone, subsequent to the staggered-bypass reaction system.

Abstract: A process for making ethylbenzene and/or styrene by reacting toluene with methane in one or more microreactors is disclosed. In one embodiment a method of revamping an existing styrene production facility by adding one or more microreactors capable of reacting toluene with methane to produce a product stream comprising ethylbenzene and/or styrene is disclosed.

Abstract: Process for production of styrene by dehydrogenation of ethylbenzene in a reactor system comprising a dehydrogenation reactor and a fast riser catalyst regenerator.

Abstract: A radial reactor for utilization for catalytic reactions of gaseous or liquid feedstreams including an annular catalyst bed, wherein the material contained within the catalyst bed includes an active catalyst material, contained within an outer ring-shaped layer of the catalyst bed, and a generally inert material, contained within an inner ring-shaped layer of the catalyst bed, wherein the generally inert material includes a potassium-containing compound, such as potassium oxide, hydroxide, carbonate or bicarbonate.

Abstract: Process for the production of vinyl aromatic monomers which comprises: a) feeding an aromatic stream and an olefinic stream to an alkylation unit; b) feeding the reaction product coming from the alkylation section to a first separation section; c) recovering the mono-alkylated aromatic hydrocarbon and the heavy bottom product from the first separation section; d) feeding the mono-alkylated aromatic to a dehydrogenation section; e) feeding the reaction product coming from the dehydrogenation section to a second purification/separation section; f) also feeding the heavy bottom product of step (c) to the second purification/separation section; g) recovering a stream consisting of the vinyl aromatic monomer with a purity higher than 99.7 by weight.

Abstract: In a regenerative reforming facility using a series of moving beds, a direct supply of regenerated catalyst, optionally reduced is passed into at least two of the reactors of the series. Spent catalysts from different reactors are passed into a common mixing apparatus so as to provide a homogeneous degree of coke on the spent catalysts which are thereafter passed to a regenerator. The feedstock and the intermediate effluents continue to circulate in succession relative to the reactors. The invention makes it possible in particular to reduce the operating pressure of the units to less than 0.2 MPa.

Abstract: A process for the catalytic dehydrogenation of a first unsaturated hydrocarbon to form a second unsaturated hydrocarbon which has one olefinically unsaturated bond more than the first unsaturated hydrocarbon and otherwise an unchanged carbon skeleton, which process comprises contacting in a first step a feed comprising the first unsaturated hydrocarbon with a first dehydrogenation catalyst having a temperature parameter T1 and a selectivity parameter S1, and contacting in a second step a reaction product of the first step comprising the first unsaturated hydrocarbon and the second unsaturated hydrocarbon with a second dehydrogenation catalyst having a temperature parameter T2 and a selectivity parameter S2, such that T1<T2 and S1<S2.

Abstract: The present invention is a process for producing styrene by dehydrogenation of ethylbenzene, which contains the steps of (i) feeding a raw material gas containing ethylbenzene and steam to a first dehydrogenating step to produce a reacted gas containing ethylbenzene, styrene and hydrogen in the presence of a dehydrogenation catalyst, (ii) feeding the reacted gas obtained in the first dehydrogenating step to an oxidizing step to combust at least part of hydrogen in the presence of an oxidation catalyst, and (iii) feeding the reacted gas obtained in the oxidizing step to a second dehydrogenating step to produce styrene from ethylbenzene in the presence of the dehydrogenation catalyst, with maintaining the carbon dioxide-generating ratio in the second dehydrogenating step at a level less than 2.1 times that at the initial stage of the reaction.

Abstract: In this invention, a new structure for the units using a series of moving beds, characterized by a direct supply of regenerated catalyst from at least two of the reactors of the series, is described. The feedstock and the intermediate effluents continue to circulate in succession relative to the reactors. The invention makes it possible in particular to cross a new threshold in the reduction of the operating pressure of the units.

Abstract: The invention involves a method for producing styrene, using at least two separate reactors, by feeding a 1-phenylethanol-rich reaction mixture to a first reactor, transferring the partially catalytically dehydrated mixture to a second reactor or to a distillation unit, and separating the mixture into a fraction of low-molecular compounds and transporting it to an outlet, and to a fraction containing high-molecular compounds and transporting it to the second reactor, or feeding a part of the catalytically dehydrated mixture to the distillation unit and the other part to the second reactor, optionally recycling a part to the first reactor, and/or optionally transporting a part to another reactor, and/or to the distillation unit or to another distillation unit; provided that part of the reaction mixture of at least one of the reactors is transported to the distillation unit. The invention further pertains to an apparatus for performing this method.

Abstract: Process for the production of aromatic compounds, such as reforming, that uses at least one fixed catalyst bed with a base of platinum and 0.08% rhenium. In said process, before moving onto the bed, the feedstock undergoes a heat exchange with the effluent that is obtained from the process, whereby the exchange is carried out with a pressure drop that is less than 1 bar and a temperature difference that is less than 70° C. The beds are preferably radial and those that are located at the top of the reactor are covered by a cloth layer. The process preferably uses at least two fixed catalyst beds, whereby the first bed (in the direction of circulation of the feedstock) has an Re/Pt ratio by weight that is greater than that of the second bed, and whereby the second catalyst preferably contains at least 0.08% of Re.

Abstract: The invention provides process and apparatus for conducting an endothermic reaction of an organic compound in the presence of molecular hydrogen and of multicomponent solids. The process comprises contacting the compound with a solid catalyst for the endothermic reaction and a hydrogen oxidizing solid reagent intermixed with the solid catalyst. Organic products of the endothermic reaction are produced, with evolution of molecular hydrogen. The solid catalyst becomes gradually deactivated by formation of carbonaceous deposits thereon. The evolved hydrogen undergoes an exothermic reaction with the hydrogen oxidizing solid reagent to form a reduction product which comprises deactivated hydrogen oxidizing solid reagent.

Abstract: A method increases the feed throughput for a process of dehydrogenating light hydrocarbons without loss of conversion or selectivity by increasing the catalyst volume in only the final reactor of at least three reaction zones. The catalyst volume of the final reactor may be increased relative to the other reactors by extending the inner and outer screens that define a radial flow bed therein. Maintaining a low LHSV by increasing the catalyst volume in only the final reactor greatly reduces the expense of improving the capacity and yield of such a process. This method provides the most benefit to moving bed reactor systems since modifications are limited to the last reactor. A further benefit is derived from the simplified method of raising only a section of the last reactor to increase the catalyst volume.

Abstract: A process for producing styrene by oxidative dehydrogentation of ethylbenzene, wherein the dehydrogenation of ethylbenzene is conducted through at least the following steps (1) to (3), whereby styrene can be produced in a high yield by controlling the lowering of the selectivity of an oxidation catalyst in hydrogen oxidation by removing an alkaline substance contained in the reaction mixture to be fed to step (2) beforehand: step (1): a step of dehydrogenating ethylbenzene in the presence of a dehydrogenation catalyst to obtain a reaction mixture containing styrene and hydrogen; step (2): a step of bringing the reaction mixture into contact with an oxidation catalyst to selectively oxidize the hydrogen contained in the mixture, thereby forming water; step (3): a step of bringing the oxidized mixture into contact with a dehydrogenation catalyst to dehydrogenate the unreacted ethylbenzene contained in the mixture, thereby obtaining styrene.

Abstract: The fouling in a styrene production process involving the dehydrogenation of ethylbenzene is reduced by removing polymerizable components of the gaseous dehydrogenation effluent prior to the condensation of the effluent in the main condenser system. This involves the scrubbing of the gaseous effluent with organic condensate from the main condenser system to remove styrene, divinylbenzene and other polymer precursors which may be present and sometimes some of the ethylbenzene. The scrubber may include a reboiler and stripping section and function as a full fractionator thereby reducing the need for downstream distillation.