Reactor and method for performing a chemical reaction

Abstract

The present invention relates to a reactor (100, 200) for carrying out a chemical reaction, comprising a reaction vessel (10) and one or more reaction tubes (20), in which a power input element (41) is guided into the reaction vessel (10) for electrical heating of the reaction tubes (20). The power input elements (41) each have a rod-shaped portion (43) extending in a wall passage (15) through the wall (14) of the reaction vessel (10), whereby a connecting chamber (60) from which the rod-shaped portion (43) protrudes is arranged outside the reaction vessel (10) adjacent to the wall (14) of the reaction vessel (10) through which the rod-shaped portion (43) passes in the wall passage (15). Cooling panels (61) through which a cooling fluid can flow are provided in the connecting chamber (60) and are arranged between at least two or at least two groups of the rod-shaped portions (43) protruding into the connecting chamber. A corresponding method is also the subject of the present invention.

Description

Technical Field

[0001] The present invention relates to a reactor and a method for carrying out a chemical reaction according to the preamble of the independent claim.

Background Art

[0002] In many processes in the chemical industry, reactors are used in which one or more reactants pass through heated reaction tubes where they react catalytically or non-catalytically. Heating in particular helps to overcome the activation energy required for the ongoing chemical reaction. This reaction can proceed endothermically overall or exothermically after overcoming the activation energy. The present invention relates in particular to strong endothermic reactions.

[0003] Examples of such processes are steam cracking, various reforming processes, in particular steam reforming, dry reforming (carbon dioxide reforming), mixed reforming processes, dehydrogenation processes of alkanes, etc. In steam cracking, the reaction tubes are guided through the reactor in the form of a coil having at least one U-shaped bend in the reactor, while tubes passing through a reactor without a U-shaped bend are usually used in steam reforming.

[0004] The present invention is suitable for all such processes and the design of reaction tubes. The articles "Ethylene", "Gas Production", and "Propene" in Ullmann's Encyclopedia of Industrial Chemistry, for example, the publication dated April 15, 2009, DOI: 10.1002 / 14356007.a10_045.pub2, the publication dated December 15, 2006, DOI: 10.1002 / 14356007.a12_169.pub2, and the publication dated June 15, 2000, DOI: 10.1002 / 14356007.a22_211 are hereby incorporated by reference for purely illustrative purposes.

[0005] The reaction tubes of the corresponding reactors have conventionally been heated using burners. In this case, the reaction tubes are sent through a combustion chamber in which burners are also arranged.

[0006] However, as described, for example, in DE 10 2015 004 121 A1 (similarly EP 3 075 704 A1), the demand for synthesis gas and hydrogen produced, for example, regardless of the presence or absence of reduced local carbon dioxide emissions, is currently increasing. However, this demand typically cannot be met in processes where combustion reactors are used by combustion of fossil energy carriers. For example, other processes are excluded for reasons such as high costs. The same applies to the production of olefins and / or other hydrocarbons by steam cracking or dehydrogenation of alkanes. Even in such cases, processes with a low amount of carbon dioxide emitted at least in situ are desired.

[0007] In contrast to this background, the aforementioned DE 10 2015 004 121 A1 proposes, in addition to combustion, the electrical heating of a reactor for steam reforming. In this case, one or more voltage sources supplying a three-phase alternating voltage to three external conductors are used. Each external conductor is connected to a reaction tube. A star circuit is formed in which a pipeline opens and the reaction tubes are conductively connected to a collector to realize a star point. In this way, the collector ideally remains at zero potential. With respect to the vertical line, the collector is arranged below and outside the combustion chamber and preferably extends transversely to the reaction tubes, i.e., horizontally. Similarly, WO 2015 / 197181 A1 discloses a reactor in which the reaction tubes are arranged in a star point circuit.

[0008] In addition to the direct heating of the reaction tube through which current flows, there are also a variety of concepts regarding the indirect electrical heating of the reaction tube. In particular, as described in WO 2020 / 002326 A1, indirect electrical heating can be carried out in the form of external electrical heating. For example, as disclosed in WO 2019 / 228798 A1, internal heating is also possible. In addition to resistance heating or impedance heating, for example, as described in WO 2017 / 072057 A1, inductive electrical heating of the reaction tube or the catalyst bed can be carried out. Inductive heating can, for example, heat an internal or external heating element or the reaction tube itself. The direct (non-inductive) heating of the reaction tube is also disclosed in DE 10 2015 004 121 A1. For heating, the basic concept can be realized with polyphase or single-phase alternating current, or direct current. In the case of direct heating of the reactor by direct current or using single-phase alternating current, a star circuit with a zero-potential star point cannot be realized, but the power input can be realized in basically the same way. The present invention is suitable for all variants of electrical heating.

[0009] DE 23 62 628 A1 discloses a tubular furnace for the heat treatment of a liquid or gaseous medium in a metal tube that can be heated by resistance heating, where the tube heated by resistance heating is conductively connected to a power line via an electrical connection at the end of the heated portion. US 2014 / 0238523 A1 relates to a device for heating a pipeline system for molten salt, the device comprising at least two pipelines, in both cases with electrical resistance heating elements extending along these pipelines, where a potential close to ground potential is set at each electrical resistance heating element at at least one end, from where the electrical resistance heating elements are remotely connected to a connection of a direct current power source or, in both cases, to a phase of an n-phase alternating current power source.

[0010] The device for heating a fluid disclosed in WO 2020 / 035575 A1 comprises at least one conductive pipeline and / or at least one conductive pipeline segment for receiving the fluid, and at least one direct current power source and / or DC voltage source, and each pipeline and / or each pipeline segment is assigned a respective direct current power source or DC voltage source connected to the respective pipeline and / or the respective pipeline segment, and each direct current power source and / or DC voltage source is designed to generate an electric current in the respective pipeline and / or the respective pipeline segment, and each pipeline and / or each pipeline segment is heated by Joule heat generated when the electric current passes through the conductive pipe material for heating the fluid, and the device has a plurality of pipelines and / or pipeline segments, and the pipelines and / or pipeline segments are interconnected to form a pipe system for receiving the fluid.

[0011] The fixed bed reactor known from EP 2 805 762 A1 has an inflow path for a raw material gas for a catalytic reaction and an outflow path for a reformed gas, a catalytic reaction vessel connected to the inflow path and the outflow path and containing a catalyst, a catalyst holder having air permeability and holding the catalyst, and a drive mechanism for moving the catalyst up and down by moving the catalyst holder up and down.

[0012] WO 2004 / 091773 A1 discloses an electrically heated reactor for carrying out gas reactions at high temperatures. The reactor consists of a reactor block, one or more monolithic modules surrounded by a housing and made of a material suitable for electrical heating, channels extending through the modules and designed as reaction channels, and a device for conducting or inducing an electric current in the reactor block. The safety during operation of such a reactor should be enhanced in that the housing of the reactor block comprises a double-wall jacket that hermetically seals the reactor block and at least one device for supplying an inert gas to the double-wall jacket.

[0013] In particular, the power input in such electrically heated reactors has proven to be a problem due to the high currents and temperatures. Therefore, the object of the present invention is to improve the corresponding electrically heated reactor for carrying out chemical reactions.

Prior art documents

Patent documents

[0014]

Patent document 1

Patent document 2

Patent document 3

Patent document 4

Patent document 5

Patent document 6

Patent document 7

Patent document 8

Patent document 9

[0015] [Non-Patent Document 1] Ullmann's Encyclopedia of Industrial Chemistry, DOI: 10.1002 / 14356007.a10_045.pub2, April 15, 2009 [Non-Patent Document 2] Ullmann's Encyclopedia of Industrial Chemistry, DOI: 10.1002 / 14356007.a12_169.pub2, December 15, 2006 [Non-Patent Document 3] Ullmann's Encyclopedia of Industrial Chemistry, DOI: 10.1002 / 14356007.a22_211, June 15, 2000 [Summary of the Invention]

[0016] In view of this background, the present invention proposes a reactor and a method for performing a chemical reaction according to the preamble of the independent claims. Embodiments are the subject of the dependent claims and the following description.

[0017] In the concept of a furnace that is usually partially electrified and forms the basis of the present invention (the term "furnace" is generally understood to refer to the corresponding reactor or at least its insulated reaction space), the reaction tubes, for example, or their corresponding tube portions (hereinafter also simply referred to as "tubes") themselves are used as electrical resistors for generating heat. This approach not only has the advantage of being more efficient compared to indirect heating by external electrical heating elements, but also has a high achievable heat flux density. However, as stated at the beginning, if the heating proves to be advantageous, it is also possible within the scope of the present invention to carry out any other type of electrical heating (directly or indirectly, in the form of resistance, impedance, or inductive heating, by single-phase or polyphase alternating current, or using direct current). Within the scope of the present invention, there is also the possibility of providing a part of the total heat output used in the furnace by the combustion of chemical energy carriers.

[0018] Therefore, even if electrical heating is mentioned in this specification, the presence of additional non-electrical heating is not excluded. In particular, it is also conceivable that the contributions of electrical heating and non-electrical heating change over time as a function of, for example, the supply and price of electricity, or the supply and price of non-electrical energy carriers such as natural gas.

[0019] When heating with polyphase alternating current, the current is supplied to the directly heated reaction tubes via M separately connected phases. The conductive reaction tubes connected to the M phases can also be electrically connected to the star point. The number of phases M is in particular 3 and corresponds to the number of phases of a conventional three-phase current power supply or network. However, in principle, the present invention is not limited to the use of 3 phases and can also be used with a larger number of phases, for example 4, 5, 6, 7, or 8 phases. The phase offset is in particular 360° / M, that is, 120° in the case of three-phase alternating current.

[0020] In electric heating using polyphase alternating current, equipotentialization between phases is achieved by a star circuit at the star point that obviates the electrical insulation of the connected pipelines. This represents a particular advantage of such furnace concepts since the breakage of the metal reaction tubes for insulating specific parts is undesirable, especially when high temperatures are used and the required material and construction costs are high.

[0021] However, the measures proposed by the present invention and described below are equally suitable for the use of single-phase alternating current and direct current, and the present invention can be used in both reactors heated with alternating current and reactors heated with direct current or corresponding hybrid forms. As described above, the present invention is also suitable for use in indirectly heated reaction tubes. Compared to the alternating current configuration, for example, in the direct current configuration, only the type of current source and the region of the reaction tube facing the power input or corresponding energized part are different. In the latter case, the electrical connection of the different tube parts is only optionally carried out. Since there is no electrically neutral star point in the direct current configuration, it is necessary to provide a suitable current discharge element to safely return the current to the outside. The latter can be designed in the same way as the power input described below. The connection chamber described below can be present in the upper region but can be omitted since the mobility requirements are eliminated.

[0022] In the terms of the claims, the present invention relates to a reactor for carrying out a chemical reaction, having a reaction vessel (i.e., a thermally insulated or at least partially thermally insulated region) and one or more reaction tubes, wherein a power input element for the electrical heating of the reaction tubes is led into the reaction vessel. According to the present invention, each power input element has a rod-shaped part, and each rod-shaped part extends in a wall passage through the wall of the reaction vessel.

[0023] In particular, the first region can be arranged at the first end of the straight pipe portion, and the second region can be arranged at the second end on the opposite side of the first end. In particular, the first region can be arranged in the upper region of the reactor, and the second region can be arranged in the lower region of the reactor, or vice versa. In other words, the first region and the second region are particularly arranged at both ends of the reaction vessel or its internal space, and the internal space of the reaction vessel between the first region and the second region particularly corresponds to the intermediate region. The first region can represent, for example, 5%, 10%, or 20% of the end of the internal space at one end of the reaction vessel, or can include it, while the second region can represent, or include, 5%, 10%, or 20% of the other opposite end of the internal space of the reaction vessel. In particular during the operation of the reactor, the first region is arranged at the bottom and the second region is arranged at the top.

[0024] Within the scope of the present invention, the connection chamber from which the rod-shaped portion protrudes is arranged outside the reaction vessel, adjacent to the wall through which the rod-shaped portion of the current input element extends, that is, a wall passage is formed. Depending on the type of power input, the connection chamber can be arranged below or beside the reaction vessel, so the wall can be the bottom wall or the side wall.

[0025] The rod-shaped portion is connected, particularly within the connection chamber, for example via a suitable intermediate portion or intermediate element, to a flexible contact element such as a strand, power strip, layered strip, or current spring. These flexible contact elements are fixed to the rigid contact element using the end that is not connected to the rod-shaped portion. The rigid contact element is usually fixedly arranged within the connection chamber, for example in an insulated manner in the wall, and is powered, for example, by a DC or AC transformer. In particular, the flexible contact element compensates for the longitudinal movement of the rod-shaped portion within the wall passage.

[0026] According to the present invention, a cooling panel through which a cooling fluid can flow is provided within the connection chamber and is arranged between at least two of the rod-shaped portions protruding into the connection chamber, or between at least two groups.

[0027] The present invention will be further described below with reference to an arrangement in which a number of tube portions of one or more reaction tubes each extend between a first region and a second region within a reaction vessel and extend through an intermediate region between the first region and the second region, where, for the electrical heating of the tube portions, the tube portions within the first region are each electrically connected or connectable to one or more power connections of a power source, either in the case of a DC configuration for one or more DC connections, or in the case of a single-phase or polyphase AC power source for one or more phase connections ( "external conductors") to an AC power source. Alternatively, as also used above, in the case of indirect heating which is likewise possible, connection elements for the corresponding heating devices are guided through the wall of the reaction vessel.

[0028] As described above, in the corresponding arrangement of the present invention, each AC voltage is in this case provided by a polyphase AC configuration via a phase connection, and the AC voltages of the phase connections are phase-shifted in the manner described above. For example, a supply network or a suitable generator and / or transformer can function as a polyphase AC power source. The tube portions of this configuration form in particular a star circuit and are conductively connected to each other at the respective opposite ends with respect to the power input, i.e., in the second region.

[0029] On the other hand, in another arrangement, in the case of a DC configuration, the same or different electrostatic potentials are supplied via one or more DC connections, and in particular, current recovery elements are provided at the respective opposite ends of the power input. The same applies when using single-phase AC current from one or more current sources in a comparable manner.

[0030] In the intermediate region, the tube portions in the arrangement referred to in the present invention pass through the reaction vessel particularly freely, i.e., without mechanical support, without electrical contact, and / or without fluid or purely mechanical cross-connections to one side. In this arrangement, the tube portions extend particularly substantially or completely straight in the intermediate region, where "substantially straight" should be understood to mean that there is an angular deviation of less than 10° or 5°.

[0031] In particular, the cracking reaction in steam cracking is a strongly endothermic reaction. The supply of energy required for the reaction by direct heating (ohmic resistance) requires a high current intensity, which is provided by one or more transformers arranged outside the reactor in the aforementioned reactor concept.

[0032] In all of the above concepts of electrical heating, the current must be conducted from the outside to the inside of the adiabatic reactor and into the process conduction region with as low losses as possible (low electrical resistance). In the latter case, an endothermic reaction with a process medium flowing very fast (high heat transfer) inside the tube results in a very effective cooling of the reaction tube or a very high heat flux density inside the tube. Thus, the desired direct heat transfer from the at least partially electrically heated tube material to the process gas is achieved within the process conduction tube.

[0033] A particular problem is associated with the above-described low-loss supply of high-voltage current to the process conduction tube. When current is supplied to the tubes inside the reactor, this supply has to be carried out via lines that cannot be cooled by direct convective heat transfer to a cooler process gas, as will also be explained below. In this case, there must be no unacceptable temperature rise in regions with low cooling efficiency. In addition, this supply has to overcome a sharp temperature rise of up to 900 K (maximum temperature difference between the environment and the reactor) within a short path length (partially less than 1 meter).

[0034] To reduce heat losses and achieve high system efficiency, it is essential to arrange the electrically directly heated reaction tubes in a heat-insulated box (herein called the reaction vessel). When passing through the heat-insulated walls of the reaction vessel, the current conductors have to overcome the quasi-insulated zones without generating unacceptably high local temperatures in these regions.

[0035] Thus, within the particularly preferred scope of development of the invention described, in order to achieve this goal, a power input configuration in which each tube part or each group of tube parts is electrically connected is provided in the first region of the reactor, i.e., the region of power input. The tube parts are provided in such a number that each one or each group of a plurality of tube parts is connected to each one of the power input configurations, and vice versa. The number of power input configurations provided within the scope of the invention depends, in the case of an AC configuration, on the number of phase connections of a polyphase AC power supply or, alternatively, this number corresponds to the number of DC connections. If an AC configuration is used, it can be made the same as the number of phase connections or an integer multiple thereof. In the latter case, for example, two of the power input configurations can be connected, in each case, to each one of the phase connections such as an AC power supply.

[0036] In this case, each power input configuration comprises one or more contact passages that are adjacent to at least each one of the tube parts within the first region and extend through the power input configuration. One or more contact passages within the power input configuration can, in each case, extend straight through the power input configuration or in the form of a U-shaped bend, as will be explained in more detail below. The contact passages are, in particular, designed as bends reinforced by walls. The reaction tubes without a U-shaped bend are, in particular, sleeves reinforced by walls.

[0037] One or more contact passages within the power input configuration can be designed with any one or more components, and the one or more components are attached to the tube part and firmly to the tube part in a high-temperature resistant manner or are joined in the form of a continuous part of the reaction tube or each continuous part thereof. As will be explained below, it has generally been proven advantageous to design with as few components as possible in all developments.

[0038] In the former case, the tube portion extending between the first region and the second region in the reactor can be welded to a ready-made component through which one or more contact passages extend, or the corresponding additional component can be molded onto the tube portion extending between the first region and the second region in the reactor. In the latter case, on the one hand, a tube portion extending between the first region and the second region in the reactor can be provided, and on the other hand, a continuous tube forming the contact passages of each power input configuration can be provided, and additional components of the power input configuration can be provided by molding start, direction change, or welding.

[0039] When it is mentioned above and below that the power input configuration comprises one or more contact passages "adjacent to at least each one of the tube portions in the first region", this is understood to mean that the contact passages of the power input configuration, together with each tube portion between the first region and the second region, form a continuous channel for the process fluid to be guided through the tube portion.

[0040] In particular, the internal tube space of each tube portion between the first region and the second region, in this case, in particular, without any significant taper or expansion, follows the corresponding contact passage, where "significant" taper or expansion means a taper or expansion of more than 10% of the cross-sectional area. The term "contact passage" is used in a particular embodiment of the present invention to refer to a region where the "contact passage" is a continuous extension of the tube portion in the first region and there is an electrical connection to the electrical connection via a metal component.

[0041] The term "firmly bonded in a high-temperature resistant manner" means that two or more metal parts are firmly bonded to each other and the connection is permanent at temperatures from 500 °C to 1,500 °C, in particular from 600 °C to 1,200 °C, or from 800 °C to 1,000 °C, i.e., during normal operation, such a connection does not separate at such temperatures. A firmly bonded connection with high-temperature resistance can in particular be designed as an intermetallic connection established such that no non-metallic material remains between the connected parts. Such a connection is in particular produced by welding, start of forming, or change of direction. Such a connection can also be a connection where no structural differences are observed at the transition of the connection part, in particular a connection where no additional metal is used for the connection.

[0042] In the developments of the invention described, the walls of the contact passages of the power input configuration are each connected to one of each of the power input elements, and each of the power input elements has, as described above, in each case at least one rod-like shape extending in the wall passage through the wall of the reaction vessel. In contrast to strands etc., for example, the rod-like parts in all developments of the invention are in particular integrally formed from a conductive material such as metal (i.e., not in the form of particularly parallel or intertwined wires). The rod-like part can be designed as solid or at least partially tubular, i.e., as a hollow rod. The rod-like part is perpendicular to the wall of the reaction vessel and has a longitudinal extension that is at least twice, in particular at least three times, four times, or five times, for example up to ten times, the size of the maximum transverse direction extension parallel to the wall of the reaction vessel. The rod-like part can have, for example, a circular, elliptical, triangular or polygonal cross-section, or any other shape.

[0043] The power input elements of the power input configuration can each attach the respective rod-like part directly to the wall of the contact passage or, as a result of being integrally manufactured, can transition into the contact passage. However, it is also possible to provide one or more intermediate elements, each of which forms part of the power input element.

[0044] The cooling panel provided within the connection chamber provided by the present invention is designed to be flat in at least one part, that is, the cooling panel extends between two virtual or real boundary surfaces arranged at a distance from each other, and the distance between the boundary surfaces defines the thickness of the cooling panel, and the extension along the boundary surface is greater than twice, five times, ten times, or twenty times or more of this thickness. The boundary surfaces can be flat or curved boundary surfaces so that the cooling panel is flat and planar, but in this case, it can also be curved so that the cooling panel is flat, semi-cylindrical or partially cylindrical. Different cooling panels can also have different dimensions or designs. The "boundary surface" is the surface that defines the maximum thickness of the cooling panel. The cooling panel does not necessarily have to contact these boundary surfaces over the entire surface.

[0045] These dimensions are applied individually to each cooling panel, that is, the first cooling panel can be arranged obliquely or vertically with respect to the second cooling panel. A plurality of cooling panels can rotate relative to each other, particularly about an axis parallel to the longitudinal extension of the rod-shaped part of the power input element and perpendicular to the wall of the reaction vessel.

[0046] The cooling panel can be configured such that, in particular, the cooling fluid flows through corresponding supply openings and removal openings for the cooling fluid in a direction that generally corresponds to a direction perpendicular or parallel to the rod-shaped part, for example, on a side surface parallel to the rod-shaped part.

[0047] The thickness of the cooling panel can be in the range of 0.5 cm to 10 cm, particularly 1 cm to 5 cm, at least in the part of the aforementioned dimensions.

[0048] In particular, the connection chamber can have side walls extending perpendicular to the wall of the reaction vessel, and in any case, the rod-shaped portion of the power input element extends through this side wall in the wall passage. One or more additional cooling panels can be arranged on at least one of the side walls or parallel to at least one of the side walls. Similar to the cooling panels described above, these cooling panels can be designed with basic dimensions.

[0049] In particular, the connection chamber can also have parallel walls extending parallel to the wall of the reaction vessel, and in any case, the rod-shaped portion of the power input element extends through this parallel wall in the wall passage, that is, for example, this parallel wall which is the bottom wall or the side wall, and the aforementioned element is arranged between the mentioned wall of the reaction vessel and the parallel wall of the connection chamber. The parallel wall can be designed as at least partially a hollow wall and configured to allow the aforementioned or additional cooling fluid to flow through.

[0050] This is particularly advantageous within the scope of the present invention when a connection chamber is used that does not have a device for providing forced convection in the gas atmosphere surrounding the cooling panel, such as a blower, a fan, etc. In the present specification, according to the understanding among experts, forced convection is understood to mean convection caused by an external mechanical action on the fluid. A pressure difference is generated by the corresponding mechanical action, causing the fluid to flow.

[0051] When using forced cooling of the rod-shaped portion of the power input element in the gas chamber, the forced cooling is dominant or radiative (excluding natural convection), and it is possible to design a cooling chamber with cooling panels that is airtight to the outside but gas-permeable to the reaction vessel (in particular, through the wall passage). Therefore, a particularly preferred development of the present invention includes this feature. Since gas exchange such as required in the case of forced convection is not necessary, for example, an atmosphere with less oxygen can be applied inside the reaction vessel including the cooling chamber.

[0052] The present invention enables the rod-shaped part of the power input element to be movably received in the wall of the reaction vessel without the need for an airtight seal that would be necessary, for example, to avoid leakage of combustible gas into the environment if the reaction tube were to suffer damage (“coil shredder”). Thus, within the scope of the present invention, the wall passage can be made significantly more compact and permanent because no sealing material is required. Advantageously here, all components emerging from the cooling chamber to the environment have a very small compensating movement, so that the implementation of the airtightness with respect to the reaction vessel wall itself is here significantly simplified.

[0053] In addition to the corresponding dimensioning and design of the power input element itself, the cooling described in the present invention ensures that a sufficiently low temperature is maintained overall, particularly for connecting highly conductive and / or flexible contact elements. The active cooling outside the insulated reaction vessel proposed within the scope of the present invention influences the temperature distribution of the outer part of the rod-shaped part of the power input element (i.e., the part protruding into the connection chamber). The cooling panel provided within the connection chamber within the scope of the present invention can also be understood as a cooled intermediate wall and ensures an increased heat dissipation from the rod-shaped part.

[0054] By using the present invention, the use of materials in the design of the power input element or its rod-shaped part can be reduced. In the case of purely passive cooling, only a very low heat development rate in the rod-shaped part may be allowed to avoid overheating in the case of a permanent load. The resulting increase in the amount of material required for this purpose is undesirable from the perspective of the cost and mechanical load in the system.

[0055] Within the scope of the present invention, a sufficiently low temperature is achieved in the connection region of the rod-shaped part, so that, for example, a copper-containing connection element that is very conductive but highly sensitive to temperature can be connected. The use of very highly conductive connection elements minimizes the electrical losses in the supply lines. In addition, these connection elements can be designed to be flexible at a sufficiently low temperature in order to absorb the thermal expansion of each part of the reaction tube during operation in this way, and this expansion is transmitted to the rod-shaped part of the power input element.

[0056] Therefore, in a particularly advantageous development of the present invention, the rod-shaped part of the power input element in the connection chamber is designed with a contact element of the corresponding type, that is, a contact element having a higher conductivity than the material of the rod-shaped part. Alternatively or additionally, these contact elements may be flexible contact elements such as strands, power strips, laminated strips, or current springs, as described above. In this development, these flexible contact elements are fixed to a rigid contact element fixedly arranged in the connection chamber at the end that is not connected to the rod-shaped part, as described above. The rigid contact element can in particular be fixed to the aforementioned parallel walls and / or can extend through this parallel wall.

[0057] Since the electrical resistance of many metal materials increases with the increase in temperature, the heat output loss can be reduced by the decrease in the average temperature of the rod-shaped part of the power input element due to forced cooling within the scope of the present invention. For example, in a flexible strand element connected thereto, the efficiency of the system can also be increased.

[0058] Due to its very low electrical conductivity, for example, demineralized water or completely demineralized water having a conductivity of less than 10 μS / cm at 25°C, particularly less than 5, 1, 0.5, or 0.1 μS / cm, is advantageously used as a cooling fluid within the scope of the present invention. In addition, the arrangement of the cooling panel is carried out in particular with respect to sufficient protection against short circuits (in particular by maintaining a minimum distance).

[0059] According to a particularly preferred development of the invention, the cooling panel can be formed from parallel metal sheets that are connected to each other by laser welding or roll welding and expand in a cushion-like manner.

[0060] Particularly advantageously, the rod-shaped portions protruding into the cooling chamber each have a cross-sectional area of at least 10 square centimeters, preferably at least 30 square centimeters, and particularly at least 50 square centimeters, at least at one point. By using a correspondingly high cross-sectional area, particularly low component temperatures can be ensured.

[0061] Advantageously, as described above, the rod-shaped portions of the power input elements are each guided longitudinally movably in their wall passages passing through the wall of the reaction vessel. The freedom of movement thus ensured is particularly advantageous for the mechanical behavior of the reaction tube, which is mainly governed by the thermal expansion of the tube by several decimeters during the operation of the reactor. Due to the freedom of movement, the bending load on the reaction tube that occurs in the case of rigid fixation is reduced. On the other hand, as will be described later, in the case of alternating current heating, the reaction tube can be fixed to a rigid stub bridge on the roof of the reactor in a second region, and in this way, even in the case of the corresponding longitudinal movement of the rod-shaped portions of the power input elements, a stable suspension is provided. With their advantageous dimensions having a sufficiently high line cross-section, the rod-shaped portions of the power input elements ensure reliable lateral guidance of the reaction tube. On the other hand, as described above, components emerging from the cooling chamber into the environment, particularly by means of the connection in the cooling chamber via flexible contact elements, have a very small compensating movement.

[0062] The reaction carried out in the reactor according to the invention requires high temperatures, so the electrical connections in the first region need to be realized, for the steam reforming, in a high temperature range of, for example, about 900 °C. This is made possible by the measures proposed by the invention through the selection of suitable materials and their sufficient sizing. At the same time, this connection is intended to have high electrical conductivity at high temperatures, as well as high mechanical stability and reliability. In the case of the use of alternating current heating and star point connection, a failure of the electrical connection results in an asymmetric potential at the star point, which in turn leads to an undesirable current flow in the system components and, as a result, to an immediate shutdown of the safety-related parts of the system. The invention provides an advantage over the prior art by avoiding such situations.

[0063] Compared to the theoretically equally possible contact outside the reaction vessel where the reaction tube has to be led out of the reaction vessel, the contact provided by the invention for the tube part within the reaction vessel has, in this case, the advantage that the path of the electrical heat input is clearly defined since there is no need to guide the electrically heated tube part from the warm inner space to the colder outer space. By the contact according to the invention, a spatially very uniform external thermal boundary condition for the electrically heated tube part can be achieved by completely arranging the tube part within the reaction vessel. This results in process engineering advantages, for example, the expected excessive coke formation in the heated and externally insulated passage can be avoided.

[0064] Within the scope of the invention, the power input element, the contact passage, and the tube part can be formed from the same material or from materials whose electrical conductivities differ from each other by 50% or less, 30% or less, 10% or less (as is customary among experts, from the point of view of the material constants), or preferably, are the same. For example, the components mentioned can also be formed from steel of the same steel grade. Using the same or closely related materials can simplify shaping or welding. On the other hand, the contact elements connected within the cooling chamber can be formed from other materials that may have a lower temperature resistance.

[0065] In a preferred embodiment, the power input element, the contact path, and the tube portion have or are formed from a heat-resistant chromium-nickel steel alloy having high oxidation or scale resistance and high carburization resistance.

[0066] For example, the heat-resistant chromium-nickel steel alloy can be an iron-containing metal containing 0.1 to 0.5 wt% carbon, 20 to 50 wt% chromium, 20 to 80 wt% nickel, 0 to 2 wt% niobium, 0 to 3 wt% silicon, 0 to 5% tungsten, and 0 to 1 wt% other components, where in each case these components total to a non-ferrous percentage.

[0067] For example, materials with standard designations GX40CrNiSi25-20, GX40NiCrSiNb35-25, GX45NiCrSiNbTi35-25, GX35CrNiSiNb24-24, GX45NiCrSi35-25, GX43NiCrWSi35-25-4, GX10NiCrNb32-20, GX50CrNiSi30-30, G-NiCr28W, G-NiCrCoW, GX45NiCrSiNb45-35, GX13NiCrNb45-35, GX13NiCrNb37-25, or GX55NiCrWZr33-30-04 can be used in accordance with DIN EN 10027, Part 1, "Materials". These have been proven to be particularly suitable for use at high temperatures.

[0068] In all cases described above, the connecting element and the tube portion may be formed from the same material or from materials having an electrical conductivity that differs by 50% or less, 30% or less, 10% or less from each other (from the perspective of material constants), or preferably, the same. For example, the connecting element and the tube portion can also be formed from steel of the same steel grade. The use of the same or closely related materials can facilitate the integral design of the connecting element and the tube portion, for example, by molding or welding.

[0069] In the second region, all the tube parts within the reaction vessel can be conductively connected to each other by means of rigid connection elements ("stub bridges") in the case of heating by polyphase alternating current, or this connection is carried out in groups by means of a plurality of rigid connection elements.

[0070] In this case, i.e., in the case of heating by polyphase alternating current, the conductive connection is carried out such that at least a substantial equipotentialization of the phases connected to the first region is obtained, as described. One or more connection elements, in particular, are known from the prior art and connect the connected tube parts in a fluid collection and non-fluid distribution manner, in contrast to the collector arranged outside the reactor. The equipotentialization within the reaction vessel proposed in the development of the present invention described has the advantage that the degree of freedom of the potential is almost complete or the current feedback via the neutral conductor is significantly reduced.

[0071] As a result, the current dissipation via the header connection to other parts of the process system is minimized, and a high level of impact protection is achieved. Outside the reaction vessel, in contrast to the guiding of the reaction tubes through the wall of the reaction vessel required for equipotentialization, the advantage of very spatially uniform external thermal boundary conditions also becomes the process-related advantage already described above in this context.

[0072] The realization of the corresponding star circuit, combined with the power input described via the longitudinally guided power input element, overall creates a configuration that enables efficient energization with stable fixation while withstanding the stresses mainly resulting from the high coefficient of thermal expansion.

[0073] The present invention will first be described below with reference to the reaction tubes and reactors used for steam reforming. However, as will be described later, the present invention can also be used for other types of reactors, as will be described later. Generally, as described above, the reactor proposed by the present invention can be used for carrying out any endothermic chemical reaction.

[0074] Reaction tubes typically used in steam reforming typically have at least one U-shaped bend. For example, these can form so-called two-pass coils. They have two tube portions within the reaction vessel and intersect with each other via (exactly) one U-shaped bend, so basically have an (elongated) U-shape. The portions entering and exiting the reaction vessel, especially the portions entering the heated tube portion seamlessly or without transitions related to the flow, are herein called the "supply portion" and the "extraction portion" (also referring to the reaction tubes described below). Such reaction tubes always exist in plurality.

[0075] Therefore, in this development, the reactor can be designed such that the tube portions each comprise two tube portions of a plurality of reaction tubes arranged at least partially side by side within the reaction vessel, and the two tube portions of the plurality of reaction tubes in each case pass through each other in a first region via a U-shaped bend. In particular, as described above, one of each two tube portions in the second region is connected to the supply portion, and the remainder of each two tube portions in the second region is connected to the extraction portion.

[0076] In this case, one or more contact passages within the power input configuration can comprise or represent a U-shaped bend. Since there are a plurality of reaction tubes having U-shaped bends, a plurality of U-shaped bends can also in each case be provided in the corresponding number to each power input configuration and thus be connected to the current connection in this way. In this way, mechanical fixation can be improved and the number of components can be reduced. However, alternatively, even when a plurality of U-shaped bends are energized via one power connection, it is also possible to provide a power input configuration for each U-shaped bend, for example, to ensure the individual longitudinal mobility of power input elements that may have different thermal expansions.

[0077] The developments of the present invention described can also be applied when a reaction tube having two supply parts and one extraction part is used. In such a reaction tube, the two supply parts are both connected to one tube part in any case. The extraction part is also connected to the tube part. In a typical Y-shaped connection region, the tube part connected to the supply part transitions to the tube part connected to the extraction part. Not only the tube part connected to the supply part, but also the tube part connected to the extraction part may or may not have one or more U-shaped bends respectively.

[0078] For example, a reaction tube as shown in FIG. 8C can be used. In these reaction tubes, the tube part connected to the supply part has no U-shaped bend, but the tube part connected to the extraction part has a U-shaped bend.

[0079] However, a reaction tube as shown in FIG. 8B can also be used. In these reaction tubes, the tube parts connected to the supply part each have a U-shaped bend, and the tube part connected to the extraction part has two U-shaped bends.

[0080] It is even possible to use a reaction tube as shown in FIG. 8A. In these reaction tubes, the tube parts connected to the supply part each have three U-shaped bends, and the tube part connected to the extraction part has two U-shaped bends.

[0081] However, in addition to the developments described above for the two-passage coil, developments suitable for use with so-called four-passage coils can also be used. The four-passage coil has four essential straight tube parts. However, even a configuration having more even numbers of straight tube parts is possible.

[0082] More generally speaking, a correspondingly designed reactor comprises one or more reaction tubes, each of which has an even number of four or more tube portions connected in series with each other via a number of U-shaped bends, the number of U-shaped bends being one less than the number of tube portions connected in series with each other via U-shaped bends, and the U-shaped bends starting from the first U-shaped bend in the first region and being alternately arranged in the first and second regions.

[0083] Here, the "U-shaped bend" is understood to mean, in particular, a tube portion or pipe component with a partially circular or partially elliptical, in particular semi-circular or semi-elliptical, tube bend. The starting point and the end point have cut surfaces that are adjacent to each other in particular in one plane.

[0084] If each of the U-shaped bends is arranged in the first region within the reaction vessel and is energized accordingly, it can be formed in the form of a contact passage in the power input configuration according to the invention or can represent a part of such a contact passage. Thus, the connected power input element projects into the connection chamber.

[0085] As described above, the corresponding reactor can be designed in particular as a reactor for steam reforming, in particular by the selection of heat-resistant materials and the geometric configuration of the reaction tubes.

[0086] Typically, the reaction tubes used for steam reforming do not typically have a U-shaped bend within the reaction vessel. However, in this case, each of the tube portions comprises a tube portion consisting of a plurality of reaction tubes, and the tube portions within the reaction vessel are arranged at least partially side by side in a non-fluidly communicating manner, and in any case, are connected to a supply portion for the fluid in the first region and an extraction portion for the fluid in the second region. The fluid supply portion and the extraction portion do not cause a fluid flow that extends in the same direction as the tube portion, or in particular, exceeds 15° deflection compared to the fluid flow within the connected tube portion. The supply portion and the extraction portion are, in particular, also formed integrally with the tube portion, i.e., in particular, in the same tube configuration. For steam reforming, the reaction tubes may also, in particular, be provided with a suitable catalyst.

[0087] In this development, the contact passage of the power input configuration according to the invention represents a straight tube portion or a channel. In this case, the power input element can be attached to the reaction tube in the second region, in particular in a sleeve manner.

[0088] In all cases, the number of metal connections (e.g., welding or soldering connections) can be reduced or even completely eliminated by forming the power input element, the contact passage, and optionally the tube portion from as few individual parts as possible. This can enhance mechanical stability and reliability. In a particularly advantageous embodiment, the power input element and the contact passage can each be implemented as a single molded article, or as described above, a part of the process conducting tube can be made directionally changeable and / or a part of the process conducting tube can be formed as an integral component of the corresponding molded part.

[0089] The metal connections or metal transitions reduced within the scope of the present invention can lead to local changes in electrical resistance and thus hot spots. Hot spots can lead to a shortening of the service life due to local temperature increases and peaks in mechanical stress due to rapid local temperature gradients. This is avoided within the scope of the present invention.

[0090] The integral formation of as many components as possible results in mechanical stability, reliability, and a reduction in the individual components. As mentioned above, high mechanical stability is desirable since a failure can lead to a critical safety situation. According to the embodiments described from the perspective of the present invention, the principle of the reaction tube resistively heated with polyphase alternating current in a star circuit is technically feasible in a high temperature range, namely especially above 500 °C, above 600 °C, above 700 °C, or above 800 °C.

[0091] The present invention also relates to a method for performing a chemical reaction using a reaction vessel and a reactor having one or more reaction tubes, wherein a power input element is guided into the reaction vessel for the electrical heating of the one or more reaction tubes.

[0092] According to the present invention, a reactor is used, and the power input elements having the reactor each have a rod-shaped portion, and the rod-shaped portions extend through the wall of the reaction vessel in respective wall passages. A connection chamber from which the rod-shaped portions protrude is arranged outside the reaction vessel, adjacent to the wall of the reaction vessel through which the rod-shaped portions extend in their wall passages. A cooling panel through which a cooling fluid can flow is provided in the connection chamber and is arranged between at least two of the rod-shaped portions protruding into the connection chamber or between at least two groups.

[0093] In a particularly preferred development of the present invention, a reactor is used, and a large number of the tube portions of the one or more tube portions having the reactor each extend between a first region and a second region within the reaction vessel, and the first region for heating the tube portions is electrically connected to one or more power connections of a current source respectively.

[0094] In this development, a reactor is used, which has, in a first region, a power input configuration to which one or each group of the tube portions is electrically connected, each having a rod-shaped portion that passes through the wall of the reaction vessel in a wall passage. The connection chamber from which the rod-shaped portions protrude is arranged outside the reaction vessel, adjacent to the wall of the reaction vessel through which the rod-shaped portions extend in their wall passages. A cooling panel through which a cooling fluid can flow is provided in the connection chamber and is arranged between at least two of the rod-shaped portions protruding into the connection chamber or between at least two groups.

[0095] For further features and advantages of the corresponding method, in which a reactor according to one of the above-described developments of the present invention is advantageously used, reference is made to the above description.

[0096] The present invention will be further elucidated below with reference to the accompanying drawings showing developments of the present invention, with reference and comparison to the prior art.

Brief Description of the Drawings

[0097]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 6C

Figure 7A

Figure 7B

Figure 8A

Figure 8B

Figure 8C

Figure 9

[0098] In the following figures, elements that are functionally or structurally corresponding to each other are denoted by the same reference numerals and are not repeatedly described for clarity. When the components of the device are described below, the corresponding descriptions are related to the method executed thereby in any case, and vice versa. The description of the figures repeatedly refers to alternating current heating. However, as mentioned, the present invention is also equally suitable for the use of direct current for heating. Here, the above description is referred to.

[0099] Figure 1 schematically shows a reactor for carrying out a chemical reaction according to a non-inventive embodiment.

[0100] Here, the reactor indicated by 300 is set to carry out a chemical reaction. For this purpose, the reactor particularly has a heat-insulated reaction vessel 10 and reaction tubes 20. Here, a large number of tube portions of the reaction tubes 20, indicated by 21 in only two cases, respectively extend between a first zone 11' and a second zone 12' within the reaction vessel 10. The reaction tubes 20, which will be described in more detail below with reference to FIG. 2, are attached to the ceiling or support structure of the reaction vessel by a suitable suspension 13. In the lower region, the reaction vessel can particularly have a furnace (not shown). Needless to say, in any case, a plurality of reaction tubes can be provided here and thereafter.

[0101] FIG. 2 schematically shows a reactor, indicated in its entirety by 100, for carrying out a chemical reaction according to an embodiment of the present invention.

[0102] The zones previously designated by 11' and 12' here take the form of regions 11 and 12. The tube portions 21 for heating the tube portions 21 within the first region 11 can in any case be electrically connected to the phase connections U, V, W of the polyphase AC power supply 50. A specific type of connection such as a switch is not shown.

[0103] In the embodiment of the present invention shown here, the tube portions 21 are integrally connected to one or more reaction tubes 20 and are conductively connected to each other in the second region 12 by connection elements 30 arranged within the reaction vessel 10. A neutral conductor can also be connected.

[0104] Therefore, in the reactor 100 shown here, (although a plurality of such reaction tubes 20 may be provided,) a plurality of tube portions 21 of the reaction tubes 20 are arranged side by side within the reaction vessel 10. The tube portions 21 intersect with each other via U-shaped bends 23 (only partially shown) and are connected to a supply portion 24 and an extraction portion 25.

[0105] In the first region 11, a first group of U-shaped bends 23 (lower side in the figure) are arranged side by side, and in the second region 12, a second group of U-shaped bends 23 (upper side in the figure) are arranged side by side. The second group of U-shaped bends 23 are formed in the connecting element 30, and the pipe portion 21 extends from the connecting element 30 in the second region 12 to the first region 11.

[0106] Within the scope of the present invention, the use of the connecting element 30 is optional but advantageous. On the other hand, the development of the present invention described below relates in particular to the development of means for power input in the first region 11. The latter is carried out by using a power input element 41, which is shown here in a very simplified manner and only one of which is shown. These are part of the power input configuration and project into a cooling chamber 60, which is provided with a cooling panel 61 and is described in more detail with reference to FIGS. 5A and 5B, in particular as described with reference to FIG. 4.

[0107] FIG. 3 schematically shows a reactor for carrying out a chemical reaction according to a development of the present invention, which is designated as 200 in its entirety.

[0108] In the reactor 200, the pipe portion, which is designated as 22 here for the sake of contrast, in each case comprises a pipe portion 22 consisting of a plurality of reaction pipes 20, the pipe portions 22 being arranged side by side in a non-fluidly communicating manner within the reaction vessel 10 and in each case being connected to a supply portion 24 and an extraction portion 25 respectively. For the remaining elements, express reference is made to the above description with respect to the previous figures.

[0109] Repeating, within the scope of the present invention, the use of the connecting element 30 is optional but advantageous. Again, the power input element 41, the connecting chamber 60, and the cooling panel 61 are shown in a very simplified manner. The power input element can have a sleeve-shaped region 49 arranged around the reaction pipe 20 or the pipe portion in the first region 11.

[0110] FIG. 4 shows a detailed view of the first region 11 of the reactor 100 according to, for example, FIG. 2. A power input configuration 40 is arranged in the first region 11, and a reaction tube 20 is connected to the power input configuration. Here, the tube portions 21 of the reaction tube shown in cross section transition into each other via a U-shaped bend 23.

[0111] The U-shaped bend 23 is formed within a contact passage 42 having a reinforcing wall, and the contact passage is adjacent to the two tube portions 21 within the first region 11. The walls of the contact passage 42, and thus the walls of the U-shaped bend 23, are connected to the aforementioned power input element indicated as 41 as a whole. This power input element has a rod-shaped portion 43 that extends in the wall passage 15 through the wall 14 of the reaction vessel 10 in each case, as shown between the dashed lines. The wall passage 15 is shown with an exaggerated width. The rod-shaped portion is accommodated within the wall passage 15 so as to be movable in the longitudinal direction and is covered, for example, with a heat insulating material 16.

[0112] Outside or adjacent to the wall 14 of the reaction vessel 10, the aforementioned connection chamber 60 is arranged together with a cooling panel 61, which will be further described with reference to FIGS. 5A and 5B.

[0113] In the example shown, the rod-shaped portion 43 is adjacent to a further rod-shaped portion 45, the temperature of which decreases increasingly as the distance to the reaction vessel 10 increases, in particular due to cooling by the cooling panel 61. The further rod-shaped portion transitions into a power input pin 46 to which two connection elements 66, for example in the form of strands, for connecting the phases U, V, W are attached.

[0114] FIGS. 5A and 5B show a partial view of the reactor 100 having a connection chamber 60 according to the development of the present invention in the longitudinal direction (FIG. 5A) and in cross section (FIG. 5B). In the cross section (FIG. 5B), only a few selected elements are shown, and the number of elements shown only partially corresponds to each other for reasons indicating a more general applicability. FIGS. 5A and 5B are in each case significantly simplified, to the extent possible for providing the very large number of elements shown in an actual reactor.

[0115] As can be seen particularly in FIG. 5A, the rod-shaped portions 43 of the power input elements each extend through the wall 14 of the reaction vessel 10 in the wall passage 15. The connection chamber 60 in which the rod-shaped portions 43 project is arranged outside the reaction vessel 10, adjacent to the wall 14 of the reaction vessel 10 through which the rod-shaped portions 43 extend in their wall passages 15.

[0116] A cooling panel 61 is provided in the connection chamber 60 and is arranged as can be seen particularly in FIG. 5B. Cooling fluid can flow through the cooling panel, and the cooling panel is arranged between at least two of the rod-shaped portions 43 projecting into the connection chamber 60 or between at least two groups.

[0117] The connection chamber 60 has side walls 62 extending perpendicular to the wall 14 of the reaction vessel 10 through which the rod-shaped portions 43 extend in each case, and one or more further cooling panels 63, seen in FIG. 5B and not shown separately in FIG. 5A, can also be arranged on at least one of the side walls 62.

[0118] The connection chamber 60 has parallel walls 64 shown in FIG. 5A, which extend parallel to the wall 14 of the reaction vessel 10 through which the rod-shaped portions 43 extend, and the parallel walls 64 are formed in at least one part as at least a hollow wall and are likewise configured such that cooling fluid can flow through. The connection chamber 60 is designed without a device for providing forced convection within the gas atmosphere 65 surrounding the cooling panel 61 and the rod-shaped portions 43.

[0119] In the connection chamber 60, a flexible connection element shown as a strand 66 in FIG. 5A is connected to the rod-shaped portion 43 and is fixed to a rigid contact element 67 using the end not connected to the rod-shaped portion 43, and the rigid contact element 67 is arranged so as not to move within the connection chamber 60 and is here fixed to an insulating receptacle (not specified in more detail) of the bottom 64.

[0120] In the decomposition furnace, generally called a 6-pass coil, the six straight pipe portions 21 have two 180° bends, namely, a U-shaped bend 23 above or in the second region 12, and three 180° bends, namely, a U-shaped bend 23 below or in the first region 11 (the latter having a corresponding power input configuration), in addition to the reaction tube 20 previously shown in FIGS. 1 and 2. Variants with fewer passes are also used. For example, the so-called 2-pass coil has only two straight pipe portions 21 and only one 180° bend or U-shaped bend 23. When applied to electric heating, this variant can be regarded as a combination of a 6-pass decomposition furnace (FIGS. 1 and 2) and a reforming furnace (FIG. 3 having a reaction tube without a U-shaped bend 23).

[0121] Power input can be carried out in each case at the lower (or only) U-shaped bend at one point for each reaction tube 21. In each case, the M reaction tubes can be electrically coupled to each other with a phase shift of 360° / M using a common connection element 30. In a first alternative, a particularly large connection element 30 can be used in each case for each coil package or for all reaction tubes 20 considered. However, in a second alternative, the use of two smaller-sized connection elements 30 is also possible.

[0122] The first alternative described is shown in FIG. 6B, and the second alternative described is shown in FIG. 6C in a cross-sectional view through the tube portion 21, where the corresponding reaction tubes 20 are shown in FIG. 6A in a view perpendicular to the figures in FIGS. 6B and 6C. For the designation of the corresponding elements, refer to FIG. 1. Needless to say, on the one hand, there is probably a U-shaped bend 23 arranged, and on the other hand, the connection element 30 with another U-shaped bend 23 having connections to phases U, V, W via a power input configuration 40 (shown very schematically here) is arranged in different planes corresponding to the first region 11 and the second region 12 of the reactor. It should be emphasized again that the presence and arrangement of the connection element 30 within the scope of the present invention are purely optional or arbitrary.

[0123] This concept can also be applied, in this case, to a coil or reaction tube 20 having four passages or tube portions 21 (so-called four-passage coil) with one, two, or four stub bridges or connecting elements 30. Corresponding examples are shown in FIGS. 7A and 7B, and the four connecting elements 3 are shown in FIG. 6B. For better illustration, the U-shaped bends 23 are shown here by dashed lines (U-shaped bends in the second region 12 of the reactor) and solid lines (U-shaped bends in the first region 11). For clarity, the elements are only partially numbered with reference numerals.

[0124] The connection chamber 60 in the deployment shown in FIGS. 6A to 6C and 7B is designed as explained in principle and is therefore only shown here in a very schematic form.

[0125] Although FIGS. 8A to 8C have already been referred to, these show further reaction tubes for use in a reactor according to the deployment of the present invention. The reaction tubes and tube portions are, in some cases, only provided with reference numerals here. The supply and extraction portions can be inferred from the flow arrows shown. In particular, the power input configuration 40 or the connection chamber 60, which can be designed in the manner described above, is shown very schematically by dashed lines.

[0126] FIG. 9 shows a detailed view of the first region 11 of the reactor 200, and in each case, the elements shown have already been described in connection with FIG. 4. However, in contrast to FIG. 4, here the reaction tube 20 does not have a U-shaped bend, and the tube portions 21 are arranged along a common central axis. The non-curved transition region is denoted by 23a. For example, instead of the sleeve in the reactor 200 according to FIG. 3, a corresponding deployment can be used. The configuration can also be arranged, in particular, on the side wall of the reactor 200, in which case it is rotated by 90° compared to FIG. 9.

[0127] Similarly here, the transition region 23a is formed in a contact passage 42 having a reinforcing wall adjacent to two tube portions 21 in the first region 11. For details, refer to FIG. 4. Here too, the wall passage 15 is shown with an exaggerated width. Similarly here, the rod-shaped portion is movably accommodated in the wall passage 15 in the longitudinal direction and is covered, for example, with a suitable heat insulating material 16. However, the wall passage 15 can, in particular, have a different design far removed from the figures shown here for the creation of further mobility. This also applies to an optional bellows configuration 44.

Claims

1. A reactor (100, 200) having a reaction vessel (10) and one or more reaction tubes (20) for carrying out a chemical reaction, wherein for the electrical heating of the reaction tubes (20), a power input element (41) is guided into the reaction vessel (10), and the reactor (100, 200) - the power input element (41) each has a rod-shaped portion (43) extending through the wall (14) of the reaction vessel (10) in each respective wall passage (15), - a connection chamber (60) in which the rod-shaped portion (43) projects is arranged outside the reaction vessel (10) adjacent to the wall (14) of the reaction vessel (10) in which the wall passage (15) is formed, - a cooling panel (61) through which a cooling fluid can flow is provided in the connection chamber (60) and is arranged between at least two of the rod-shaped portions (43) projecting into the connection chamber (60) or between at least two groups, characterized by a reactor (100, 200).

2. The plurality of tube portions (21, 22) of the one or more reaction tubes (20) each extend between a first region (11) at a first end of the reaction vessel (10) within the reaction vessel (10) and a second region (12) at a second end of the reaction vessel (10) opposite the first end of the reaction vessel (10) within the reaction vessel (10). For the electrical heating of the tube portions (21, 22), the tube portions (21, 22) in the first region (11) are each electrically connected or connectable to the power connections (U, V, W) of a power source (50), and a power input configuration (40) to which one or each group of the tube portions (21, 22) is electrically connected is provided in the first region (11). The power input configuration (40) each has one of the power input elements (41) having the rod-shaped portion (43), and each of the rod-shaped portions passes through the wall (14) of the reaction vessel (10) in the wall passage (15). The reactor (100, 200) according to claim 1.

3. Each of the cooling panels (61) has, between boundary surfaces whose distance defines the thickness of the cooling panel (61), an extension along the boundary surface, and the extension of the cooling panel (61) along the boundary surface is 2 times, 5 times, 10 times, or 20 times or more the thickness of the cooling panel (61). The reactor (100, 200) according to claim 1 or claim 2.

4. The boundary surface whose distance defines the thickness of the cooling panel (61) is flat or curved. The reactor (100, 200) according to claim 3.

5. At least two of the cooling panels (61) are parallel in the longitudinal extension direction of the rod-shaped portion (43) and are rotated relative to each other about an axis perpendicular to the wall (14) of the reaction vessel (10). The reactor (100, 200) according to claim 3 or claim 4.

6. The cooling panel (61) is configured such that the cooling fluid flows through a direction perpendicular or parallel to the longitudinal extension direction of the rod-shaped portion (43). The reactor (100, 200) according to claim 3 or claim 4 or claim 5.

7. The thickness of the cooling panel (61) is in the range of 0.5 cm to 10 cm, at least in its cross section. The reactor (100, 200) according to any one of claims 3 to 6.

8. The connection chamber (60) has a side wall (62) extending perpendicular to the wall (14) of the reaction vessel through which the rod-shaped portion (43) passes and extends, and one or more additional cooling panels (63) are arranged on at least one of the side walls (62). The reactor (100, 200) according to any one of claims 1 to 7.

9. The connection chamber (60) has a parallel wall (64) extending parallel to the wall (14) of the reaction vessel (10) through which the rod-shaped portion (43) passes and extends. The parallel wall (64) is formed at least in one part as a hollow wall and is configured such that the cooling fluid or an additional cooling fluid flows through it. The reactor (100, 200) according to any one of claims 1 to 8.

10. The connection chamber (60) is formed without using a device for providing forced convection within the gas atmosphere (65) surrounding the cooling panel (61) and the rod-shaped portion (43). The reactor (100, 200) according to any one of claims 1 to 9.

11. The reactor (100, 200) according to any one of claims 1 to 10, wherein the connection chamber (60) is airtight except for the wall (14) of the reaction vessel (10) forming the wall of the connection chamber (60).

12. The copper-containing connection element and / or the flexible connection element (66) fixed to a rigid contact element arranged so as not to move into the connection chamber (60) using an end not connected to the rod-shaped portion (43) is connected to the rod-shaped portion (43) in the connection chamber (60). The reactor (100, 200) according to any one of claims 1 to 11.

13. The reactor (100, 200) according to any one of claims 1 to 12, wherein each of the rod-shaped portions (43) protruding into the cooling chamber has a cross-sectional area of at least 10 square centimeters, at least partially.

14. The reactor (100, 200) according to any one of claims 1 to 13, formed as a reactor (100) for steam decomposition or as a reactor (200) for steam reforming, dry reforming, or catalytic dehydrogenation of alkanes.

15. A method for performing a chemical reaction using a reactor (100, 200) having a reaction vessel (10) and one or more reaction tubes (20), wherein for the electrical heating of the reaction tubes (20), a power input element (41) is guided into the reaction vessel (10), and the method includes: - Each of the power input elements (41) has a rod-shaped portion (43) that passes through the wall (14) of the reaction vessel (10) and extends in the wall passage (15) in each case. - A connection chamber (60) in which the rod-shaped portion (43) protrudes is arranged outside the reaction vessel (10) adjacent to the wall (14) of the reaction vessel (10) through which the rod-shaped portion (43) passes in the wall passage (15). - A cooling panel (61) through which a cooling fluid can flow is provided in the connection chamber (60) and is arranged between at least two of the rod-shaped portions (43) protruding into the connection chamber or between at least two groups. A method characterized in that the reactor (100, 200) is used.

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