Abstract: Systems and processes for producing isomerized alkenes are disclosed. The systems mainly include an isomerization unit, a dehydrogenation unit, and a MTBE synthesis unit. A hydrocarbon stream is fed into the isomerization unit to form iso-alkanes in a sulfur free hydrocarbon stream. The sulfur free hydrocarbon stream is heated and then combined with a sulfur-containing hydrocarbon stream comprising sulfur containing compounds to form a reactant feed stream to the dehydrogenation unit. The iso-alkanes is dehydrogenated to form iso-alkenes. The formed iso-alkenes comprising isobutylene can be used as a feed stock for the MTBE synthesis unit.

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: A process for producing olefins by cracking paraffins in the presence of methane. In the conventional steam cracking processes for olefin production, steam is used as a diluent in the feed mixture to the thermal cracker. In the processes provided herein, methane replaces steam as a diluent in the feed mixture to the thermal cracker. Replacing steam with methane as a diluent has a potential for cost savings in the construction and operation of a thermal cracking plant for olefin production. In addition, it leads to a much simpler cracking process compared to the conventional steam cracking technology as in the state of the art.

Abstract: According to one or more embodiments presently disclosed, a method for processing a chemical stream may include contacting a feed stream with a catalyst in a reactor portion of a reactor system that includes a reactor portion and a catalyst processing portion. Contacting the feed stream with the catalyst may cause a reaction forming an effluent. The method may include separating the effluent stream from the catalyst, passing the catalyst to the catalyst processing portion, and processing the catalyst in the catalyst processing portion. Processing the catalyst may include passing the catalyst to a combustor, combusting a supplemental fuel stream in the combustor to heat the catalyst, and treating the heated catalyst with an oxygen-containing gas. The supplemental fuel stream may include at least 1 mol % of one or more hydrocarbons, and a weight ratio of catalyst to hydrocarbons in the combustor may be at least 300:1.

Abstract: An integrated process, suitable for use in a new or retrofitted plant, produces an olefin or di-olefin via the dehydrogenation of an appropriate C3-C4 hydrocarbon feed includes (1) contacting the feed and a dehydrogenation catalyst having a Geldart A or Geldart B classification in a fluidized bed at a temperature from 550° C. to 760° C. and a pressure from about 41.4 to about 308.2 kPa (about 6.0 to about 44.7 psia) and a catalyst to feed ratio, w/w, from 5 to 100 to form a dehydrogenate product; separating the dehydrogenate product and unreacted starting feed mixture from a portion of the catalyst by means of a cyclonic separation system; reactivating the catalyst in a fluidized regenerator by combustion at 660° C. to 850° C., followed by contact with an oxygen-containing fluid at 660° C.

Abstract: An improved catalytic dehydrogenation process which process comprises contacting an alkane or alkyl aromatic feedstream with a dehydrogenation catalyst under catalytic conditions in an up-flow fluidized reactor, wherein the fluidized reactor comprises one or more reactors, which catalytic conditions include a temperature within a range of from 500 to 800° C., a weight hourly space velocity within a range of from 0.1 to 1000, a gas residence time within a range of from 0.1 to 10 seconds, and, subsequent to the fluidized reactor, effecting separation of entrained catalyst from reactor effluent by use of a cyclonic separation system, wherein the improvement comprises interposing a cooling means between an up-flow fluidized reactor and the cyclonic separation system to substantially halt thermal reactions, thereby effectively increasing overall molar selectivity to alkene product is provided.

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: An apparatus for reforming a hydrocarbon stream is presented. The apparatus involves changing the design of reformers and associated equipment to allow for increasing the processing temperatures in the reformers and heaters. The reformers are operated under different conditions to utilize advantages in the equilibriums, but require modifications to prevent increasing thermal cracking and to prevent increases in coking.

Abstract: A method is proposed for providing an oxygen-containing gas stream for the endothermic reaction of an initial stream comprising one or more hydrocarbons, having a predetermined oxygen concentration and a predetermined temperature, wherein a fluid fuel stream is combusted with a primary air stream at ? values of the primary air stream to the fluid fuel stream of from 0.6 to 1.2 to obtain a combustion gas stream, and a secondary air stream is admixed to the combustion gas stream to obtain the oxygen-containing gas stream for the endothermic reaction, with the predetermined oxygen concentration and the predetermined temperature of the oxygen-containing gas stream being adjusted via the flow rate and the temperature of the secondary air stream.

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: 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: A reactor design and process for the dehydrogenation of hydrocarbons is presented. The reactor design includes a multibed catalytic reactor, where each of the reactor beds are fluidized. The catalyst in the reactor cascades through the reactor beds, with fresh catalyst input into the first reactor bed, and the spent catalyst withdrawn from the last reactor bed. The hydrocarbon feedstream is input to the reactor beds in a parallel formation, thereby decreasing the thermal residence time of the hydrocarbons when compared with a single bed fluidized reactor, or a series reactor scheme.

Abstract: The present invention provides a method of increasing stability of a catalyst used in a dehydrogenation process. The method includes storing fresh catalyst in a reduction zone, passing a gas through the reduction zone, introducing hydrocarbons and hydrogen gas into a reactor positioned downstream from the reduction zone to facilitate a dehydrogenation reaction, and replenishing spent catalyst in the reactor with fresh catalyst from the reduction zone. The gas has a moisture content at or below about 4000 ppmv and a temperature at or below about 290° C. The reactor includes catalyst for increasing the rate of the dehydrogenation reaction. The moisture content of the gas may be reduced to at or below about 4000 ppmv by passing the gas through a drier or by using an inert gas stream. The temperature of the gas may also be reduced.

Abstract: Apparatuses and methods are disclosed for contacting radially flowing fluids with solid particles (e.g., catalyst) with reduced tendency for fluidization of the particles, and especially a sealing portion of the particles at the top of a particle retention zone disposed between screens at upstream and downstream positions relative to radial fluid flow. Fluidization is reduced or eliminated by offsetting openings of the screens in the axial direction, such that upstream openings in the upstream screen are above highest downstream openings in a downstream stream. The offset in openings imparts a downward flow component to radially flowing fluid, thereby reducing solid particle fluidization without the need to induce a specific pressure drop profile along the entire axial direction of the screens.

Abstract: A process and apparatus for the dehydrogenation of paraffins is presented. The process utilizes a reactor that includes a slower flow of catalyst through the reactor, with a counter current flow of gas through the catalyst bed. The catalyst is regenerated and distributed over the top of the catalyst bed, and travels through the bed with the aid of reactor internals to limit backmixing of the catalyst.

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: A process for the dehydrogenation of paraffins is presented. The process utilizes a rapid recycling of dehydrogenation catalyst between the dehydrogenation reactor and the catalyst regeneration unit. The process comprises preheating a combined hydrogen and paraffin hydrocarbon feedstream and passing the combined stream to a dehydrogenation reactor. The hydrocarbon feedstream and the catalyst pass through the reactor at a rate to limit the average residence time of the catalyst in the reactor. The catalyst is cycled to a regeneration unit, and passed through the regeneration unit to limit the average residence time of the catalyst in the regeneration unit.

Abstract: A method for improving performance of a catalyzed reaction carried out in a moving bed system having a reaction zone. A process stream is introduced into the reaction zone at a temperature, and the temperature of the catalyst introduced to the reaction zone is different from the process stream introduction temperature to increase conversion.

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 is presented for the dehydrogenation of hydrocarbons in a radial flow reactor. The process includes the continuous feeding of catalyst into the reactor and the continuous withdrawal of catalyst from the reactor, where the catalyst is modified to increase the increased density. The catalyst is a layered structure with a dense core and an active catalytic outer layer.

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: A process for catalyst regeneration is presented. The process regenerates a catalyst in a paraffin dehydrogenation process, where the reaction is endothermic. The regeneration process provides the heat for the process through heating the catalyst and removes the need for a charge heater to the dehydrogenation reactor, which in turn eliminates high temperature thermal residence time which eliminates thermal cracking of the feed and improves the overall product selectivity. In addition, plot area, equipment costs and operating complexity are reduced.

Abstract: A new P-N-P ligand in which each phosphorus atom is bonded to two ortho-fluorine substituted phenyl groups is useful in ethylene oligomerizations. In combination with i) a source of chromium and ii) an activator such as methalumoxane; the ligand of this invention may be used to prepare an oligomer product that contains a mixture of hexenes and octenes. The hexenes and octenes produced with this ligand contain very low levels of internal olefins when produced under preferred reaction conditions.

Abstract: A new P—N—P ligand is useful in ethylene oligomerizations. In combination with i) a source of chromium and ii) an activator such as methylalumoxane; the ligand of this invention may be used to prepare an oligomer product that contains a mixture of hexenes and octenes. The hexenes and octenes produced with this ligand contain very low levels of internal olefins when produced under preferred reaction conditions.

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 invention relates to a process for the production of ethylene, comprising the steps of a) thermally converting, by a pyrolysis or a partial oxidation process, a feed charge containing methane into an acetylene containing effluent, and b) in situ hydrogenating, by a non-catalytic reaction, the acetylene produced in the first step into ethylene by intimately mixing the acetylene containing effluent with an ethane feed. The process according to the invention is more efficient than other synthesis schemes, while simplifying the overall process design. This process thus offers an economically attractive scheme for mass production of ethylene from natural gas, based on a well-known and proven acetylene route.

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: A process for catalyst regeneration is presented. The process regenerates a catalyst in a paraffin dehydrogenation process, where the reaction is endothermic. The regeneration process provides the heat for the process through heating the catalyst and removes the need for a charge heater to the dehydrogenation reactor, which in turn eliminates high temperature thermal residence time which eliminates thermal cracking of the feed and improves the overall product selectivity. In addition, plot area, equipment costs and operating complexity are reduced.

Abstract: A method for producing a mixture of ethylene and carbon monoxide by contacting ethane and an oxygen source at a temperature of at least 500° C. to produce ethylene and carbon monoxide. A method for producing an alkyl propionate by steps of: (a) contacting ethane and an oxygen source at a temperature of at least 500° C. to produce ethylene; (b) contacting an alcohol, ethylene and carbon monoxide with an ethylene carbonylation catalyst to produce the alkyl propionate; and (c) separating the alkyl propionate from byproducts and starting materials. The method further comprises condensing the alkyl propionate with formaldehyde to produce an alkyl methacrylate.

Abstract: An improved process and system for the endothermic dehydrogenation of an alkane stream is described. The process and system of the present invention comprise a back-mixed fluidized bed reactor. The alkane stream is dehydrogenated in a single reactor stage by contacting the alkane stream with a back-mixed fluidized bed of catalyst. Deactivated catalyst is withdrawn from the back-mixed fluidized reactor and heated to produce hot regenerated catalyst. The hot regenerated catalyst is returned to the back-mixed fluidized bed reactor at a rate sufficient to maintain the back-mixed fluidized bed reactor at substantially isothermal conditions.

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 is presented for the dehydrogenation of hydrocarbons in a radial flow reactor. The process includes the continuous feeding of catalyst into the reactor and the continuous withdrawal of catalyst from the reactor, where the catalyst is modified to increase the increased density. The catalyst is a layered structure with a dense core and an active catalytic outer layer.

Abstract: The invention relates to a method for dehydrating alkanes, wherein the alkane is guided in a reactor for the dehydrogenation of alkanes via a catalyst, and the process may be carried out adiabatically or non-adiabatically, and the catalyst for dehydration can be regenerated after the reaction phase by means of transferring a gas, wherein said gas is guided via the catalyst after a short rinsing phase using water vapor, and said regeneration gas consists of a gas containing oxygen and of steam, and after regeneration the catalyst is freed of the gas containing oxygen by transferring steam, wherein the duration of the transfer of a gas containing oxygen is significantly reduced as compared to common methods and represents 70% or less of the total regeneration time, and the catalyst has an increased selectivity for forming alkene by means of carrying out the regeneration at a constant activity, and the catalyst is comprised of a metal of the group of platinum metals or group VIB of the periodic table of the elem

Abstract: Methods of dehydrogenating hydrocarbons to yield unsaturated compounds are described. Reactor configurations useful for dehydrogenation are also described. Hydrocarbons can be dehydrogenated, for relatively long periods of time-on-stream, in a reaction chamber having a dimension of 2 mm or less to produce H2 and an olefin. Techniques have been developed that reduce coke and allow stable, relatively long-term operation in small reactors.

Abstract: Moving bed hydrocarbon conversion processes are provided for contacting a catalyst moving downward through a reaction zone with a hydrocarbon feed, withdrawing the catalyst from the reaction zone and conveying the catalyst to a regeneration zone wherein the catalyst moves downward. The catalyst is withdrawn from the regeneration zone and passed downward to an upper zone of a particle transfer apparatus wherein the transfer of catalyst from the upper zone through an intermediate zone to a lower zone is regulated by varying the pressure of the intermediate zone and the flow rate of gas passing through the valveless conduits. A body within the lower zone is in catalyst communication with a valveless conduit and provides more consistent catalyst flows. The catalyst from the lower zone of the particle transfer apparatus is conveyed to the reactions zone.

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: The invention relates to a method for producing propylene during which a first gas mixture, which is technically free of oxygen but contains propane, water vapor and hydrogen, and which has a temperature of at least 400° C., is led into a reaction device having at least one catalyst bed as well as usual dehydration conditions. Another gas mixture, which contains propane and oxygen and which can also contain ammonia, the propane content exceeding the oxygen content, is led into the same reaction device in which it reacts with the first gas mixture while forming propylene, water vapor and hydrogen, and the formed gas mixture containing propylene, water vapor and hydrogen is drawn out of the reaction device.

Abstract: Methods of dehydrogenating hydrocarbons to yield unsaturated compounds are described. Reactor configurations useful for dehydrogenation are also described. Hydrocarbons can dehydrogenationed, for relatively long periods of time-on-stream, in a reaction chamber having a dimension of 2 mm or less to produce H2 and an olefin. Techniques have been developed that reduce coke and allow stable, relatively long-term operation in small reactors.

Abstract: The invention relates to a method for producing propylene during which a first gas mixture, which is technically free of oxygen but contains propane, water vapor and hydrogen, and which has a temperature of at least 400° C., is led into a reaction device having at least one catalyst bed as well as usual dehydration conditions. Another gas mixture, which contains propane and oxygen and which can also contain ammonia, the propane content exceeding the oxygen content, is led into the same reaction device in which it reacts with the first gas mixture while forming propylene, water vapor and hydrogen, and the formed gas mixture containing propylene, water vapor and hydrogen is drawn out of the reaction device.

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: The present development relates to a modification of the Houdry process for the dehydrogenation of aliphatic hydrocarbons, whereby the dehydrogenation cycle is extended, or lengthened, and hydrogen gas is added into the reaction. The combination of the extended cycle with the hydrogen introduction results in a surprising stabilization of the production rate in the dehydrogenation process. The hydrogen gas may be introduced through a recycle step. The process of the present development is demonstrated for the dehydrogenation of propane to propylene.

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: A process for preparing light olefins from corresponding paraffins consists of reacting said paraffins in a reactor, operating at a temperature of between 450 and 800° C., a pressure of between 0.1 and 3 atm absolute and a GHSV of between 100 and 10000 h?1, with a catalytic system containing gallium, platinum, possibly one or more alkaline or alkaline-earth metals, and a support consisting of alumina in delta or theta phase or in delta+theta or theta+alpha or delta+theta+alpha mixed phase, modified with silica, the gallium, expressed as Ga2O3, being in a quantity of between 0.1 and 33.6 wt %, the platinum being in a quantity of between 1 and 99 ppm, the alkaline or alkaline-earth metals, expressed as oxide, being in a quantity of between 0 and 5 wt %, and the silica being in a quantity of between 0.08 and 3 wt %, the rest to 100% being alumina, and regenerating said catalytic system in a regenerator by burning off the coke which has deposited on its surface, without subsequently reducing it.

Abstract: A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed. The catalyst comprises (1) at least one solid acid component, (2) at least one metal-based component comprised of one or more elements from Group 3 and one or more elements from Groups 4–15 of the Periodic Table of the Elements; and at least one of oxygen and sulfur, wherein the elements from Groups 3, Groups 4–15 and the at least one of oxygen and sulfur are chemically bound both within and between the groups and (3) at least one of at least one support, at least one filler and at least one binder. The process is such that the yield of hydrogen is less than the yield of hydrogen when contacting the hydrocarbons with the solid acid component alone.

Abstract: A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed. The catalyst comprises (1) at least one solid acid component, (2) at least one metal-based component comprised of one or more elements from Groups 1 and 2; one or more elements from Group 3; one or more elements from Groups 4–15 of the Periodic Table of the Elements; and at least one of oxygen and sulfur and (3) at least one of at least one support, at least one filler and at least one binder. The process is such that the yield of hydrogen is less than the yield of hydrogen when contacting the hydrocarbons with the solid acid component alone.

Abstract: A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed. The catalyst comprises: (1) at least one solid acid component, (2) at least one metal-based component comprised of (i) at least one of oxygen and sulfur (ii) one or more elements from Groups 5–15 of the Periodic Table of the Elements; and (iii) one or more elements from at least one of (a) Groups 1–2 and (b) Group 4; of the Periodic Table of the Elements; and (3) at least one of at least one support, at least one filler and at least one binder. The process is such that the yield of hydrogen is less than the yield of hydrogen when contacting the hydrocarbons with the solid acid component alone.

Abstract: A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed.

Abstract: A catalyst system and process for combined cracking and selective hydrogen combustion of hydrocarbons are disclosed. The catalyst comprises (1) at least one solid acid component, (2) at least one metal-based component comprised of two or more elements from Groups 4–15 of the Periodic Table of the Elements and at least one of oxygen and sulfur, wherein the elements from Groups 4–15 and the at least one of oxygen and sulfur are chemically bound both within and between the groups and (3) at least one of at least one support, at least one filler and at least one binder. The process is such that the yield of hydrogen is less than the yield of hydrogen when contacting the hydrocarbons with the solid acid component alone.

Abstract: A reactor system for oxidative conversion of hydrocarbons comprising at least one reactor tube being provided with a plurality of perforations along a wall of the tube and a reaction zone with an active catalyst arranged on tube side and/or shell side of the reactor tube; and a bed of particulates material surrounding the at least one reactor tube, the bed of particulate material being adapted to be fluidised by an oxygen containing atmosphere and to transport heat from the reactor tube.