Reactors and methods for performing chemical reactions

Abstract

The present invention relates to a reactor (100, 200) for performing a chemical reaction, comprising a reactor vessel (10) and one or more reaction tubes (20), wherein a plurality of tube segments (21, 22) of the one or more reaction tubes (20) extend within the reactor vessel, and wherein each tube segment (21, 22) is electrically connected or capable of being electrically connected to one or more current wirings in a current feeding region (11) for electrically heating the tube segment. According to the present invention, a power feeding assembly (40) is disposed in a current feeding region (11), and a corresponding segment or a corresponding group of segments (21, 22) in the segments (21, 22) is electrically connected to the power feeding assembly (40), wherein the power feeding assembly (40) has a first part (41) and a second part (42), wherein the first part (41) is drawn from an element of the corresponding segment (21, 22) or the corresponding group of segments (21, 22), or connected to the corresponding segment (21, 22) or the corresponding group of segments (21, 22) along a longitudinal axis (A). The invention extends in the region of the power supply assembly (40), wherein a first portion (41) sleeves at least partially around a second portion (42) or a second portion (42) sleeves at least partially around a first portion (41), the first portion (41) and the second portion (42) having contact surfaces (41a, 42a) that are inclined relative to the longitudinal axis (A) for mutual contact, and the power supply assembly (40) extends through the wall (14) of the reactor vessel (10) at wall openings (15). The invention also relates to a corresponding method.

Description

Technical Field

[0001] The present invention relates to a reactor and method for performing a chemical reaction as described in the preamble of the independent claims. Background Technology

[0002] Reactors are used in many processes in the chemical industry, in which one or more reactants are supplied through a heated reaction tube and a catalytic or non-catalytic reaction takes place within the tube. Specifically, heating is used to overcome the activation energy required for the chemical reaction to occur. The reaction may be endothermic as a whole, or exothermic after the activation energy is overcome. This invention particularly relates to strongly endothermic reactions.

[0003] Examples of these processes include steam cracking, various reforming processes, particularly steam reforming, dry reforming (carbon dioxide reforming), mixed reforming processes, and alkane dehydrogenation processes. In steam cracking, the reaction tubes are guided through the reactor in the form of coils, which have at least one reverse bend in the reactor, while in steam reforming, tubes without reverse bends are typically used to pass through the reactor.

[0004] This invention applies to the processes and embodiments of all such reaction tubes. Articles in Ullmann's *Encyclopedia of Industrial Chemistry*, including "Ethylene," "Gas production," and "Propene," such as DOI: 10.1002 / 14356007.a10_045.pub2 (April 15, 2009), DOI: 10.1002 / 14356007.a12_169.pub2 (December 15, 2006), and DOI: 10.1002 / 14356007.a22_211 (June 15, 2000), are cited herein for illustrative purposes only.

[0005] The corresponding reactor's reaction tubes are typically heated using a burner. The reaction tubes are guided through a combustion chamber, where the burner is also located.

[0006] However, for example, as described in DE102015004121A1 (and also EP3075704A1), the demand for syngas and hydrogen produced with or without reduction in local CO2 emissions is increasing. However, processes using combustion reactors cannot meet this demand due to the typical combustion of fossil fuels. Other processes are excluded, for example, due to high costs. The same applies to the production of olefins and / or other hydrocarbons via steam cracking or alkane dehydrogenation. In such cases, processes with at least minimal on-site CO2 emissions are also required.

[0007] Against this backdrop, the aforementioned DE102015004121A1 proposes electric heating for a steam reforming reactor in addition to combustion. Here, one or more voltage sources are used, providing three-phase AC voltage across three external conductors. Each external conductor is connected to the reaction tubes. A star connection is formed, in which the star point is achieved by a collector, to which the tubing leads, and the reaction tubes are electrically connected. Thus, the collector ideally remains without potential. Vertically, the collector is arranged below and outside the combustion chamber, and preferably transverse to the reactor tubes or extends horizontally. WO2015 / 197181A1 also discloses a reactor in which the reaction tubes are arranged in a star-shaped connection.

[0008] In principle, it is conceivable to use direct current or single-phase alternating current to electrically heat the reactor. In this case, a star connection without a potential star point cannot be achieved; however, current feeding can be substantially achieved in a similar manner. This invention applies to both variations of electric heating.

[0009] In particular, it has been found that current feeding into such electrically heated reactors is challenging due to the high current and temperature. Therefore, the objective of this invention is to improve the corresponding electrically heated reactors for performing chemical reactions. Summary of the Invention

[0010] In view of this background, the present invention provides a reactor and process for performing a chemical reaction according to the preamble of the independent claim. Examples are the subject matter of the dependent claims and the following description.

[0011] In most electric furnace concepts upon which this invention is based (the term "furnace" is generally used to refer to the corresponding reactor or at least the adiabatic reaction chamber of said reactor), at least one of the reaction tubes or corresponding tube segments (hereinafter also simply referred to as "tubes") functions itself as a resistor to generate heat. This method has higher efficiency and a higher achievable heat flux density than indirect heating via external electric heaters. Within the scope of this invention, a portion of the total heating power to be applied to the furnace may also be provided by burning chemical energy.

[0012] Therefore, if this article refers to electric heating, the existence of other non-electric heating is not excluded. In particular, the contribution of electric heating and non-electric heating can vary over time, for example, depending on the supply and price of electricity or the supply and price of non-electric energy sources such as natural gas.

[0013] In the case of heating using multiphase alternating current, the current is fed into the directly heated reaction tubes via M individually connected phases. The current-carrying reaction tubes connected to the M phases are also advantageously electrically connected at the star point. Specifically, the number of phases M is 3, which corresponds to the number of phases in a conventional three-phase current source or three-phase current network. However, in principle, the invention is not limited to the use of three phases, but can also be used with a greater number of phases (e.g., 4, 5, 6, 7, or 8 phases). In this case, the phase displacement is specifically 360° / M, that is, 120° for three-phase alternating current.

[0014] Due to the star-shaped connection at the star point, potential balance between phases can be achieved in electric heating using multiphase alternating current, making electrical insulation of the connected pipes redundant. This represents a particular advantage of this furnace concept, as rupture of the metal reaction tubes in specific insulation sections is undesirable, especially given the high temperatures used and the high material and construction costs required.

[0015] However, the measures proposed and described below according to the present invention are equally applicable to the use of direct current, and the present invention can be used in both reactors heated by alternating current and reactors heated by direct current, or in a corresponding hybrid form. In the direct current structure, the difference from the alternating current structure lies only in the type of current source and the area of ​​the reaction tubes or the corresponding current application section opposite the current feed section. In the alternating current structure, electrical connections between different tube sections can only be optionally performed. Since there is no potential-free neutral point in the direct current structure, suitable current extraction elements must be provided to safely guide the current back to the outside. In principle, this also applies to single-phase alternating current, which can also be used.

[0016] In the language of the claims, the present invention relates to a reactor for performing a chemical reaction (or heating), the reactor comprising a reactor vessel (i.e., an insulated or at least partially insulated region) and one or more reaction tubes, wherein multiple segments of the one or more reaction tubes extend within the reactor vessel, and wherein each segment is electrically connected to or can be electrically connected to one or more current terminals, and in the case of a DC current configuration, the segments are electrically connected to or can be electrically connected to one or more DC terminals, while in the case of an AC configuration, the segments are electrically connected to or can be electrically connected to one or more phase terminals (“external conductors”) of an AC power source, as detailed below.

[0017] The current feeding as understood here occurs by applying a voltage that causes current to flow. Therefore, providing voltage and feeding current are synonymous; the same applies to the terms current source and voltage source, current connection and voltage connection, and similar terms.

[0018] As described above, in a structure operating with multiphase alternating current, an alternating voltage is provided via phase connections, wherein this alternating voltage is phase-shifted as described above. In this structure, a power grid or a suitable generator and / or transformer can be used as a multiphase AC source. In this structure, a star circuit can be formed in a manner known per se, wherein the star point of the star circuit ideally has no potential.

[0019] However, in the case of a DC current structure, the same or different static potentials are fed in via a DC connection. Since a star connection is not possible here, current extraction elements or grounding elements must be provided. Single-phase AC power supplies are used in a similar manner. Here, a neutral point connection is also not possible. The terms "feeding in" and "extraction" can refer to the physical or technical direction of the current.

[0020] Within the reactor vessel, the tube segments extend at least specifically freely, i.e., without mechanical support, electrical contact, and / or fluid or purely mechanical cross-connections to each other. In particular, the tube segments have substantially straight sections, where "substantially straight" should be understood to mean an angular deviation of less than 10° or 5°.

[0021] In particular, the pyrolysis reaction in steam cracking is a strongly endothermic reaction. In order to provide the necessary energy for the reaction by direct heating (ohmic resistance), a high current is required, which in the aforementioned reactor concept is provided by one or more transformers placed outside the reactor.

[0022] The current must be conducted from the outside of the adiabatic reactor to the inside, and then to the processing zone, with minimal possible loss (low resistance). In this processing zone, the endothermic reaction, combined with the rapidly flowing process medium (high heat transfer) inside the tubes, results in very efficient cooling of the reactor tubes or a very high heat flux density inside the tubes. Thus, the desired direct heat transfer from the at least partially electrically heated tube material to the process gas is achieved within the process tubes.

[0023] A specific problem involves the low-loss supply of high-voltage current to the processing tubes, as described above. If current is to be fed into the tubes inside the reactor, this supply must be via tubes that cannot be cooled by direct convective heat transfer to the cooler process gases, as described below. This cannot result in unacceptable temperature rises in areas of lower cooling efficiency. Furthermore, over short distances (in some cases less than 1 meter), a sharp temperature rise of up to 900 K (the maximum temperature difference between the environment and the reactor) must be overcome by this supply.

[0024] To reduce heat loss and thus achieve higher system efficiency, the electrically heated reaction tubes must be placed inside an insulated box (here referred to as the reactor vessel). As the current-carrying conductors pass through the insulated walls of the reactor vessel, they must therefore overcome quasi-insulated zones without creating unacceptably high localized temperatures in these areas.

[0025] According to the present invention, to achieve this objective, power feeding components are provided in the current feeding region, wherein a pipe segment or a group of pipe segments is electrically connected to each of the power feeding components. The pipe segments are arranged such that one or a group of pipe segments can each be connected to each of the power feeding components, and vice versa. The number of power feeding components is based on the number of phase connections of the multiphase AC power source in the case of an AC current structure, or the number of power feeding components corresponds to the number of DC current connections. The number of power feeding components in the case of an AC current structure can be the same as the number of phase connections, or can be an integer multiple of the number of phase connections. When the number of power feeding components is an integer multiple of the number of phase connections, for example, two power feeding components can be respectively connected to one of the phase connections of the AC current source.

[0026] According to the invention, each of the power feeding assemblies includes a first portion and a second portion, wherein the first portion extends along a longitudinal axis from a corresponding pipe segment or a group of corresponding pipe segments or an element connected to said pipe segment or the group of corresponding pipe segments (i.e., the corresponding pipe segment or the group of corresponding pipe segments), wherein, in a region of the power feeding assembly, the first portion at least partially surrounds the second portion in a sleeve-like manner, or the second portion at least partially surrounds the first portion in a sleeve-like manner, and wherein the first portion and the second portion have contact surfaces that are inclined relative to the longitudinal axis for mutual contact. The longitudinal axis may, but does not necessarily, be parallel to the longitudinal axis of the corresponding tubular segment. The expression "at least partially" is intended to cover cases where the corresponding surrounding segment has, for example, a lateral cutout, which is provided for, for example, receiving a protruding cooling fin of the surrounded segment.

[0027] According to the invention, each power supply assembly extends further through the wall of the reactor vessel at a wall channel, wherein, in particular, the area of ​​the power supply assembly of the first portion, or the area of ​​the second portion, which in turn sleeves at least partially surrounds the first portion, is disposed in the wall channel. The "wall" of the reactor vessel may also be, in particular, the intermediate wall of a separate space where the power supply assembly is connected, for example, by a flexible strand or cable, wherein this space may be defined by at least one additional wall. This wall is specifically designed to be thermally insulated.

[0028] In the context of this invention, the first portion of the power feeding assembly can be connected to a corresponding pipe segment or group of corresponding pipe segments in any manner. For example, the first portion can be welded to, cast onto, or integrally formed with one or more reverse bends or straight pipe segments, for example by centrifugal casting. The first portion can also have a fluid channel to which the corresponding pipe segment or group of corresponding pipe segments is substantially connected, for example, welded to. Thus, more generally, in the context of this invention, there is a material connection between the first portion of the flow feeding device and the corresponding pipe segment or group of corresponding pipe segments. In particular, the form of welded connection, or the first part of the flow feeding device and the corresponding pipe section or the assembly of the corresponding pipe section are formed as one unit.

[0029] For example, as described in more detail below, the bent pipe segment may or may not extend straight or in the form of a reverse bend through the power feeder assembly. Thus, in particular, a wall-reinforced bend may be formed by a portion of the first part of the power feeder assembly. In particular, the reaction pipe without a reverse bend may be a wall-reinforced sleeve.

[0030] According to specific embodiments, for example, pipe segments extending between the power supply area and the grounding connection or star bridge in the reactor vessel can be welded to prefabricated components in the form of a first portion of the power supply section having one or more fluid channels extending therein, or the first portion can be cast onto the pipe segment. In the case where the first portion can be cast onto the pipe segment, continuous pipe can be provided, and the first portion of the power supply assembly can be manufactured by casting or welding thereon or around it.

[0031] It should be understood that the first part of the power feeding assembly does not interrupt the fluid flow in the corresponding pipe section, thus always forming a continuous channel for guiding the process fluid through the pipe section. In particular, the interior of the corresponding pipe section is also continuous in the region of the flow feeding device, and specifically there is no significant reduction or widening, where “significant” reduction or widening is intended to mean a reduction or widening exceeding 10% of the cross-sectional area.

[0032] The term "power supply assembly" is used herein to refer to the corresponding device that has a conductive connection with current via a metal component, even in some embodiments of the invention, where at least a first portion of the "power supply assembly" is a continuous continuation of a pipe segment.

[0033] In a particularly preferred embodiment of the invention, the contact surfaces of the first and second portions of the power feeding assembly can be formed with a tapered inner surface and a tapered outer surface. The tapered inner surface is formed in a sleeve-like manner, particularly in a corresponding segment at least partially surrounding the other segment, and particularly at the inner end of a recess formed to receive the portion at least partially sleeve-like. The tapered outer surface is formed in particular in a corresponding segment at least partially surrounded by the other segment, and particularly at the end of the rod-shaped region of the corresponding segment at least partially sleeve-like by the corresponding other segment.

[0034] In the sense understood here, spherical contact surfaces, hemispherical contact surfaces, segmented spherical contact surfaces, or curved contact surfaces should also be considered "inclined"; in addition, threads, threaded connections, or shapes formed in the form of splined hubs or splined shafts can be provided.

[0035] In the following text, the phrase "first part of the power feeding device" or "second part of the power feeding device" will be repeated. This is merely for linguistic simplicity and may refer to either the first or second part of all power feeding systems, or only a portion thereof.

[0036] The conical inner and outer surfaces are configured such that they can come into contact with each other by tucking or pushing together the first and second portions of the power feeding assembly. This allows for the efficient establishment of electrothermal contact surfaces between these elements without the need for potentially complex or impossible material connections. In other words, efficient current feeding can be achieved without manufacturing the entire power feeding assembly using the same material. Instead, the first and second portions can be specifically adapted to their respective desired functions. For example, the material of the first portion can be explicitly selected based on its temperature resistance and sufficient conductivity at the appropriate temperature, and the material of the second portion can be designed based on good conductivity and connectivity with other materials within a less critical range relative to the dominant temperature. Therefore, the advantageous effects of current injection via the appropriate current injection device can be achieved with fewer material techniques and manufacturing attempts, and the structure can be adapted to the desired function.

[0037] In addition to the advantages already mentioned, a particular advantage of using tapered contact surfaces is that the first and second parts of the power feeding assembly are automatically centered relative to each other, which simplifies the correct functional setup of the elements and assemblies, especially when a corresponding push force is applied.

[0038] In embodiments of the invention, the tapered contact surface can form the inner and outer surfaces of a tapered shell, or it can form the inner and outer surfaces of a tapered shell of a truncated cone. In all cases, the end of a corresponding segment, which is at least partially surrounded by another segment in a sleeve-like manner, can be fully fitted into the corresponding complementary structure of the segment that is at least partially surrounded by it in a sleeve-like manner. The use of a tapered shroud provides the maximum transmission surface, and the use of a truncated cone offers particular manufacturing advantages because, in this case, the tip of the cone does not need to be fully formed. In the case of a truncated cone, there is no potentially vulnerable tip.

[0039] In corresponding embodiments of the invention, the tapered contact surface can form a cone angle of 40° to 120°, particularly, for example, about 45° or 60°. The term "cone angle" should be understood as the angle formed by the opposing surface lines of the cone or truncated cone relative to the axis of symmetry, defining the tapered contact surface. According to the definition used herein, the cone angle corresponds to twice the angle between the axis of symmetry and each generatrix. The smaller the cone angle, i.e., the "sharper" the resulting cone or truncated cone, the larger the contact surface area for thermoelectric conversion. The smaller the cone angle, i.e., the "blunt" the cone or truncated cone, the more robust the design.

[0040] In a particularly preferred embodiment of the invention, a resiliently deformable biasing element may be provided, which presses the second part of the power feeding assembly along the aforementioned longitudinal axis in the direction of the first part. In particular, the tapered design of the contact surfaces described above allows for a permanent and secure contact to be established, as the cone or truncated cone can thus be permanently pressed into the corresponding complementary structure. This prevents the contact surfaces from separating even with different thermal expansions of the first and second parts.

[0041] The elastically deformable biasing element can be specifically designed as a (coil) spring. For example, if the first part of the power feeding assembly at least partially surrounds the second part in a sleeve-like manner, a support ring or support shell can be provided, which is screwed onto the first part and supports the corresponding spring. The spring can act directly on the second part, which is at least partially surrounded by the first part in a sleeve-like manner, or on the corresponding opposing structure. In the case of a helical spring, this can be specifically arranged around the second part. For example, a bellows or the like can also be provided instead of a helical spring. The invention is not limited to specific embodiments.

[0042] In an alternative to the tapered design of the contact surfaces, these contact surfaces can also be designed as threaded surfaces. In other words, in this embodiment of the invention, the first part of the power feeding assembly can be screwed into the second part, and vice versa. By screwing in accordingly, the expansion of the corresponding screwed-in element can be achieved, which ensures further securing of the elements even under different thermal expansion conditions, thereby ensuring further securing of the contact surfaces to each other.

[0043] In a particularly preferred embodiment of the invention, the second portion of the power supply assembly may be provided with and / or connected to surface-expanding elements. For example, these elements may be in the form of heat sinks. This allows for targeted heat dissipation from the second portion.

[0044] If, from the outset, an integral structure of the first part of the power feeding assembly and the conduit segment is not provided, in a corresponding embodiment of the invention, the components are connected in a substantially fixed manner at high temperatures. The term "substantially connected in a high-temperature resistant manner" refers to a connection in which two or more metal components are substantially interconnected, and this connection is permanent at 500°C to 1500°C, particularly 600°C to 1200°C or 800°C to 1000°C, i.e., it will not detach at these temperatures during normal operation. The substantially locked high-temperature resistant connection can particularly be formed as a metal-to-metal connection, which is performed such that no non-metallic material exists between the connected components. In particular, such a connection can be manufactured by welding, casting, or circumferential casting. The connection can also be a joint where no structural difference is observed at the transition of the connected components, particularly a joint without additional metal for the connection.

[0045] The first and second parts of the power feeding assembly, in contrast to strands or the like, are formed, particularly rigidly as a single piece (i.e., not particularly as parallel or wound wires). In particular, the first and second parts are solid structures, but it should be understood that the section that at least partially surrounds another section in a sleeve-like manner is particularly shaped as a hollow rod or tube.

[0046] The first and second portions specifically have longitudinal extensions along the longitudinal axis and perpendicular to the wall of the reactor vessel, which are at least twice the size of the maximum lateral extension parallel to the wall of the reactor vessel, particularly at least three, four, or five times, and for example, up to ten times. For example, the cross-section of the segment at least partially surrounded by the other segment can be, for example, circular, elliptical, triangular, or polygonal, or can have any other shape. In any case, the segment of the power feeding assembly that at least partially surrounds the other segment has an internal shape that corresponds to the negative shape of the segment at least partially surrounded by it.

[0047] According to the invention, current is introduced into the reaction tube to be heated or a section of the reaction tube via a power supply assembly, which is attached to the process guide reaction tube, for example, in a direction perpendicular to the local process airflow, and extends along the aforementioned longitudinal axis in that direction, i.e., particularly at the apex of a reverse bend or perpendicular to the tube's orientation in the case of a non-bent reaction tube. In the case of a non-bent reaction tube, the aforementioned longitudinal axis may also be parallel to the tube's orientation.

[0048] Specifically, the reduced free ratio conductor cross-section 'a' formed by the first and second portions can exist externally toward the reaction zone. This applies both to the region where the first portion at least partially surrounds the second portion or the second portion at least partially surrounds the first portion, and to the transition region of the reaction tube, where an increased wall thickness is preferably provided compared to the reaction tube further away from the feed section.

[0049] For any cross-sectional area S having an area A1 (square meters) in a first part having an average specific resistance ρ1 (unit: Ω×m) and an area A2 in a second part having an average specific resistance ρ2, the free conductor cross-sectional area a (unit: m / Ω) is defined as follows: a=A1 / ρ1+A2 / ρ2 A particularly advantageous embodiment of the invention includes: for any two cross-sectional regions S1, S2 representing an isosurface through the power feeding assembly (where such a cross-section may pass through a first portion alone, a second portion alone, or through the region, wherein, in the region, the first portion at least partially surrounds the second portion or the second portion at least partially surrounds the first portion), wherein, in any case, the root-mean-square (rms) value of the potential Vrms, i passing through it is constant and arranged at different distances from the AC voltage source (i.e., particularly the transformer), the root-mean-square potential Vrms, 1 of the cross-sectional region S1 closer to the transformer is always higher than the root-mean-square potential Vrms, 2 of the cross-sectional region S2 farther from the transformer, such that Vrms, 1 > Vrms, 2. The terms “closer” and “farther” here refer to the shorter and longer flow distances of the current from the current source to the respective cross-sectional regions. The use of the rms value for the potential refers to reactor operation using alternating current. In the case of direct current operation, the described relationship applies to the arithmetic mean of the potential.

[0050] The entire current feed (i.e., the power feed assembly as a whole) is further advantageously designed such that for two arbitrary cross-sectional regions S1 and S2, which are at different distances from the current source and where Vrms, 1 > Vrms, 2, the quotient a2 / a1 of the free ratio conductor cross-section a2 of the cross-sectional region S2, which is farther from the current source, and the free ratio conductor cross-section a1 of the cross-sectional region S1, which is closer to the current source, is as high as 0.5, particularly as high as 0.9, as high as 1, as high as 1.1, or as high as 2. In a particularly preferred embodiment, the quotient a2 / a1 of the free ratio conductor cross-section of any such paired regions is as high as 1.

[0051] For manufacturing reasons, for example, deviations from this preferred embodiment may occur, making even a small increase in cross-section locally acceptable. However, for conductors with their respective free ratios and cross-sections a1 =amax and a2 = two transverse regions S1 of the global extremum of amin and S2 This relationship is always advantageous for Vrms, 1 >Vrms, 2 That is, the region with the highest free ratio conductor cross-section is closer to the current source than the region with the lowest free ratio conductor cross-section.

[0052] This ensures an optimal, continuous increase in material temperature, particularly preferably reaching its maximum only in the reaction zone. As a default value regarding the temperature distribution, it can be determined that, similar to the free-ratio conductor cross-sectional distribution according to a particularly advantageous embodiment of the invention, for two arbitrary cross-sectional regions S1 and S2 at different distances from the current source and where Vrms, 1 > Vrms, 2, the temperature difference T1-T2 between the cross-sectional region S1 closer to the current source and the cross-sectional region S2 further away from the current source reaches -100K, particularly -10K, -1K, 0K, 1K, 10K, or 100K. In a particularly preferred embodiment, the temperature difference T1-T2 between all these paired surfaces is less than 0K.

[0053] This specification includes, in particular, the condition that a maximum local temperature increase of -100K, -10K, -1K, 0K, 1K, 10K, or 100K occurs throughout the current-feeding region, compared to the highest material temperature occurring in adjacent pipe sections.

[0054] Furthermore, in the power transmission assembly, the conductor cross-section a1 has a free ratio. =amax and a2 =amin's global extremum cross-sectional region S1 and S2 Temperature T1 and T2 Temperature difference T1 -T2 Further advantageously, it reaches -500K, -200K, -100K, 0K, or 100K, that is, the surface with the largest cross-section according to this embodiment of the invention is closer to the transformer and is preferably colder or at most slightly warmer than the area with the smallest cross-section.

[0055] In one embodiment of the invention, the cross-sectional area of ​​the free conductor in the power feeding assembly advantageously decreases primarily in a continuous or monotonic manner from the current feeding direction toward the reaction tube. Therefore, combined with the materials provided in this embodiment, the length resistivity depends only on the available free conductor area, and the amount of specific energy released also increases steadily in this manner. Thus, since only the amount of heat absorbed by the process gas can be effectively utilized in the reaction tube, the maximum possible utilization rate of the supplied energy can be achieved.

[0056] According to a particularly advantageous embodiment of the invention, the precise orientation of the free-ratio conductor cross-section of the power feeding assembly is also adapted to local temperature and heat transfer conditions. For example, in areas with perforations in the quasi-insulating wall of the reactor vessel (where significant heat dissipation through the insulated reactor wall is unlikely), a large free-ratio conductor cross-section is preferably used to minimize local heat dissipation in these areas, thereby limiting the upper limit of local temperature increases. In other words, the power feeding assembly advantageously has a larger free-ratio conductor cross-section in the areas with wall perforations compared to at least one other area.

[0057] As will be explained below, to avoid contact resistance, at least the first part of the current feed section and the area of ​​the contact section are preferably made of a single piece, for example, in the form of a fixed casting. In the case of a multi-part design, as an alternative, it is also possible to use a suitable connection method (e.g., friction welding) to advantageously ensure that the descriptions regarding the free ratio conductor cross-section and the maximum local temperature increase are also followed in the connected areas.

[0058] Of particular advantage is that each power feeding component has a free-ratio conductor cross-section located between the corresponding wall channel and the area of ​​electrical contact between the current feeding section and the pipe section, which is not less than 500 m / Ω, advantageously not less than 1500 m / Ω, and especially not less than 2500 m / Ω. By using a correspondingly high free-ratio conductor cross-section, particularly good current transmission can be ensured without resistance loss.

[0059] In addition to, or at least partially synonymously with, the design of the free conductor region explained above, a corresponding design based on length-specific resistance can also be provided within the scope of this invention, wherein this increases steadily, particularly continuously, from the transformer toward the reaction region. The length-specific resistance R / L (unit: Ω / m) is determined by the resistance R, the unit length L, the specific resistance ρ, and the cross-sectional area A of the free conductor.

[0060] R = L × ρ / A, therefore R / L = ρ / A.

[0061] This approach includes both variations in geometry (e.g., the variable diameter of the current-feeding array) and combinations with another material (if applicable, the other material having a different resistivity).

[0062] Advantageously, the power supply assemblies are guided longitudinally through the reactor vessel wall in their respective wall channels. This freedom of movement is particularly beneficial to the mechanical behavior of the reaction tube, which is primarily governed by a few decimeters of thermal expansion during reactor operation. This freedom of movement reduces bending loads that might occur on the reaction tube in the case of a rigid installation. Furthermore, as described below, the reaction tube can be provided with a rigid star-shaped bridge, thus providing stable suspension even with corresponding longitudinal movement of the power supply assemblies. Due to the advantageous dimensions of the power supply assemblies' sufficiently large overall cross-section, safe lateral guidance of the reaction tube is ensured.

[0063] Because the reaction in the reactor according to the invention requires high temperatures, the electrical connections in the power supply area must be implemented within a high-temperature range, for example, approximately 900°C for steam cracking. This is achievable by selecting suitable materials and their appropriate dimensions according to the measures proposed in the invention. Simultaneously, the connection should possess high conductivity, as well as high mechanical stability and reliability at high temperatures. Failure of the electrical connection leads to an asymmetric potential at the star point, and thus causes undesirable current conduction in the equipment components, resulting in a momentary safe shutdown of the equipment. The present invention provides an advantage over the prior art by avoiding this situation.

[0064] Compared to contacts that theoretically could also be made outside the reactor vessel but require the reaction tubes to be led outside, the contact of tube segments inside the reactor vessel according to the invention has the advantage of a more clearly defined electrothermal input path because it is not necessary to guide the electrically heated tube segments from the hotter internal space to the cooler external space. Due to the contact according to the invention, since the tube segments are entirely arranged inside the reactor vessel, highly uniform external thermal boundary conditions can be achieved for the electrically heated tube segments. This results in process advantages, for example, the formation of excessive localized coking that is expected in heated and externally insulated channels can be avoided.

[0065] Outside the reactor vessel or in the connection chamber, particularly in a cooling connection chamber located outside the actual reactor vessel, the power supply assembly is electrically connected to the transformer system, for example, via connecting elements such as busbars and connecting strips. The connecting strips and busbars can be made of a different material than the first or second part of the power supply assembly. Because the temperature is lower outside the reactor vessel, these connecting elements can be designed to be particularly flexible. Switching devices can be specifically installed on the primary side of the transformer system because of the higher voltage and lower current on the primary side.

[0066] In the context of this invention, the first portion and the pipe section of the power feeding assembly can be formed of the same material, or of materials whose conductivity (in the sense of a material constant, as is customary in the art) differs from each other by no more than 50%, 30%, or 10%, or advantageously, of the same material. For example, the components can also be formed of steel of the same type. Using the same or closely related materials facilitates casting or welding.

[0067] On the other hand, by using the present invention, the second part can be made of other materials, for example, materials that ensure easier processing and, for example, materials that can be connected to the expansion element in a simpler manner for current injection. The decisive criteria for selecting the material of the second part are low resistivity and the highest possible temperature compatibility. Typically, materials composed of a single metal or metal alloy selected from molybdenum (Mo), tungsten (Wo), tantalum (Ta), niobium (Nb), nickel (Ni), and chromium (Cr) can be used, containing at least 50% by weight of at least one material selected from the group consisting of molybdenum, tungsten, tantalum, niobium, nickel, and chromium. Components may also be included, for example, zirconium (Zr), carbon (C) in carbide form, and / or rare earth elements such as hafnium (Hf) and lanthanum (La).

[0068] An overview of commercially available materials that may be used in the corresponding components can be obtained from the respective manufacturers. The following is a selection of materials for which no claims of integrity are made.

[0069] Molybdenum-based materials can include, for example, pure or substantially pure molybdenum or known alloys with material names such as TZM, MHC, ML, MLR, MLS, MoILQ, MY, MoRe5, MoRe41, MW20, MW30, MW50, MoCu30, MoCu15, MZ17, MoNb10, or MT11. Tungsten-based materials include, for example, pure or substantially pure tungsten and known alloys with material names such as WK65, WVM, WVMW, S-WVMW, WC, WL, WL-S, WLZ, WRe, and WCu, as well as high-density tungsten heavy metal alloys. For example, sintered or cast pure or substantially pure tantalum, particularly well-known materials such as TaS, TaK, TaKS, Ta2.5W, or Ta10W, can be used as tantalum materials. In addition to pure or substantially pure chromium, alloys such as CFY can also be used.

[0070] In a preferred embodiment, the first part and the pipe section of the power feeding assembly are both made of or formed of a heat-resistant chromium-nickel steel alloy, which has high oxidation resistance or high scale resistance and high carburization resistance.

[0071] For example, the alloy may be an ferrous material containing 0.1% to 0.5% carbon, 20% to 50% chromium, 20% to 80% nickel, 0% to 2% niobium, 0% to 3% silicon, 0% to 5% tungsten, and 0% to 1% other components, wherein the total content of these components reaches the ferrous material content.

[0072] For example, materials with standard names according to DIN EN 10027 Part 1 "Materials" such as 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. These have proven to be particularly suitable for high-temperature applications.

[0073] In all the above cases, the first part and the pipe section of the power transmission assembly can be formed of the same material, or of a different conductivity (in the sense of a material constant, as is customary in the field) by no more than 50%, 30%, or 10%, or advantageously, of the same material. For example, the connecting elements and the pipe section can also be formed of steel of the same type. Using the same or closely related materials can facilitate, for example, the integral formation of the first part and the pipe section by casting or welding.

[0074] As described above, when heated by multiphase alternating current, all tube segments within the reactor vessel can be electrically connected to each other via rigid connecting elements (“star bridges”), or such connections can be made in groups of multiple rigid connecting elements.

[0075] By combining the corresponding implementation of the star circuit with the current feeding of the described power feeding component via longitudinal guidance, a structure is created as a whole that can provide efficient current feeding while being stably secured, wherein the secureness can withstand stress, especially caused by high thermal expansion.

[0076] This also applies to heating by direct current or single-phase alternating current feasible according to the invention, wherein, as described, there are no star points in the reactor. However, a rigid device can also be provided at the end opposite to the current feed, because the reaction tube can expand substantially freely without the need to generate voltage due to the power feed assembly provided according to the invention. Therefore, a rigid device can be provided at the end of the reaction tube opposite to the current feed, but if desired, an element corresponding to the current feed element according to the invention can also be provided. However, in any case, a movable device can be omitted.

[0077] The invention will first be described with reference to reaction tubes and reactors used for steam cracking. However, as will be discussed later, the invention can also be used in other types of reactors as described below. Generally, as stated, the reactor proposed according to the invention can be used to perform all endothermic chemical reactions.

[0078] Reactor tubes typically used for steam cracking usually have at least one reverse bend. Therefore, the reactors used according to the invention can be specifically designed for steam cracking by selecting appropriate heat-resistant materials and the geometry of the reactor tubes.

[0079] For example, the reaction tube used herein can be a so-called 2-channel coil. The 2-channel coil has two sections within the reactor vessel that connect to each other via a (precisely) reverse bend, thus essentially having a (slender) U-shape. In such an arrangement, the sections entering and exiting the reactor vessel connect seamlessly or without any flow-related transition to the heated section.

[0080] Therefore, in this embodiment, in each case, the reactor can be designed such that each tube segment comprises two tube segments of a plurality of reaction tubes, the two tube segments being arranged at least partially side-by-side in the reactor vessel, the two tube segments of the plurality of reaction tubes respectively entering each other in the first feed region via corresponding reverse bends.

[0081] In this configuration, the power supply assembly can be connected to a reverse bend. Since there are multiple reaction pipes with reverse bends, if a sufficient number of reverse bends exist, multiple reverse bends can be provided in the corresponding power supply assembly, and in this way, they can be connected to the current wiring. This improves mechanical fastening and reduces the number of components. Alternatively, for example, to ensure the longitudinal movement of the current supply elements in cases where the thermal expansion of the pipe sections may differ, even when multiple reverse bends are supplied with current via a single current wiring, a separate power supply assembly can be provided for each reverse bend.

[0082] The design of the invention just explained can also be adapted to the use of branched reaction tubes, i.e., fluid supplied from one tube segment is distributed to two or more tube segments, or fluid from two or more tube segments is combined in one tube segment. In this case, according to the invention, current can also be supplied to two tube segments of a plurality of reaction tubes in the manner explained by an electric feeding assembly, wherein the plurality of reaction tubes are arranged at least partially adjacent to each other in the reactor vessel.

[0083] In addition to the embodiments described above with reference to the 2-channel coil, embodiments suitable for use with a so-called 4-channel coil may also be used. The 4-channel coil has four substantially straight pipe sections. However, arrangements with a larger even number of straight pipe sections are also possible.

[0084] However, two sections of the plurality of reaction tubes arranged at least partially adjacent to each other in the reactor vessel are also supplied with current in the manner described herein by means of the power feeding assembly according to the invention.

[0085] "Reverse bend" is understood here specifically to refer to pipe sections or components that include partially circular or partially elliptical, particularly semi-circular or semi-elliptical pipe bends. The starting and ending ends have cutting surfaces that are adjacent to each other on a single plane.

[0086] Each of the reverse bends can take the form of a channel in the first part of the power feeding assembly according to the invention, or can form part of such a channel, provided that each is located in the current feeding region within the reactor vessel and is properly energized.

[0087] Reactor tubes typically used for steam reforming do not usually have reverse bends within the reactor vessel. However, in this case, the tube segments may each comprise segments of multiple reaction tubes, wherein the segments are not in fluid communication within the reactor vessel and are arranged at least partially adjacent to each other. In particular, the reaction tubes may also be equipped with a suitable catalyst for steam reforming.

[0088] In this embodiment, the contact channel in the power feeding assembly according to the invention is a straight pipe section or a passage. The current feeding assembly may have an area sleeved onto or integrated with the reaction tube.

[0089] In all cases, by forming the power feed assembly from as few individual components as possible, and optionally also forming pipe segments, the number of metal-to-metal connections (e.g., welded or soldered connections) can be reduced or even eliminated entirely. This can increase mechanical stability and reliability. In a particularly advantageous embodiment, the power feed assembly and pipe segments can be implemented as individual castings, or, as described, components of the process guide line can be recast, and / or components of the process guide line can be formed as integral parts of the respective castings.

[0090] Within the scope of this invention, reduced metal-to-metal connections or metal bonding can lead to localized changes in resistance, and thus hot spots. These hot spots, in turn, result in shortened lifespan due to increased local temperature, or mechanical stress peaks due to high local temperature gradients. This is avoided within the scope of this invention.

[0091] The integrated design with as many components as possible provides mechanical stability, reliability, and a reduction in the number of individual parts. High mechanical stability is desirable because, as mentioned, failure could lead to a safety hazard. The design described in this invention, utilizing the principle of multiphase AC resistance heating of the reaction tube, is technically feasible in high-temperature ranges, particularly at temperatures exceeding 500°C, 600°C, 700°C, or 800°C.

[0092] For the processes using reactors as described in the foregoing various embodiments according to the present invention, reference is made to the respective independent claims.

[0093] The present invention will be further described below with reference to the accompanying drawings, wherein embodiments of the present invention are described by referring to and comparing with the prior art. Attached Figure Description

[0094] Figure 1 A reactor for performing a chemical reaction is shown schematically, but is not an embodiment of the invention.

[0095] Figure 2 A reactor for performing a chemical reaction according to an embodiment of the present invention is illustrated schematically.

[0096] Figure 3 A reactor for performing a chemical reaction according to another embodiment of the invention is illustrated schematically.

[0097] Figure 4 A reactor with an electric feed assembly according to an embodiment of the present invention is illustrated schematically.

[0098] Figure 5 The current feed region of the reactor according to an embodiment of the present invention is shown.

[0099] Figure 6A and Figure 6B The reaction tubes and corresponding arrangements used in the reactor according to an embodiment of the present invention are shown.

[0100] Figures 7A to 7C The arrangement of reaction tubes used in a reactor according to an embodiment of the present invention is shown.

[0101] Figure 8A and Figure 8B The arrangement of reaction tubes used in a reactor according to an embodiment of the present invention is shown.

[0102] Figures 9A to 9C An alternative arrangement of reaction tubes used in a reactor according to an embodiment of the invention is shown. Detailed Implementation

[0103] In the accompanying drawings, functionally or structurally corresponding elements are indicated by the same reference numerals, and for clarity, their explanations will not be repeated. If the components of the device are explained below, the corresponding explanation will also relate to the methods performed using said components, and vice versa. The accompanying drawings repeatedly refer to heating with alternating current. However, as stated above, the invention is equally applicable to heating with direct current. Reference is made herein to the above explanation.

[0104] Figure 1 A reactor for performing a chemical reaction is shown schematically, but is not an embodiment of the invention.

[0105] The reactor designated here as 300 is configured to perform a chemical reaction. For this purpose, specifically, the reactor 300 has a reactor vessel 10 and a reaction tube 20, the reactor vessel 10 being particularly insulated, and the reaction tube 20, wherein multiple sections of the reaction tube 20 (represented here by 21 indicating only two sections) each extend between a first region 11' and a second region 12' within the reactor vessel 10. (Referring below...) Figure 2 To illustrate in more detail, the reaction tube 20 is attached to the top of the reactor vessel or to a supporting structure via a suitable suspension 13. In the lower region, the reactor vessel may, in particular, have a furnace (not shown). It should be understood that multiple reaction tubes may be provided here and below.

[0106] Figure 2 A reactor for performing a chemical reaction according to an embodiment of the present invention is schematically shown, the reactor being indicated by 100.

[0107] The areas previously designated by 11' and 12' are here referred to as areas 11 and 12, wherein each of the pipe segments 21 in the heating current feeding area 11 is electrically connected to the phase connection (U, V, W) of the multiphase AC current source 50. Switches and other specific connection types are not shown.

[0108] In the embodiment of the invention shown herein, pipe segments 21 are electrically connected to each other in region 12 by a connecting element 30 integrally connected to one or more reaction pipes 20 and disposed within the reactor vessel 10. A neutral conductor may also be connected to one or more reaction pipes 20.

[0109] In the reactor 100 shown herein, multiple segments 21 of the reaction tube 20 (although multiple such reaction tubes 20 may be provided) are thus arranged side by side in the reactor vessel 10. Each of two segments 21 merges with each other via a reverse bend 23 (shown only partially) and connects to a feed section 24 and an extraction section 25 for the working fluid.

[0110] The first set of reverse bends 23 (at the bottom of the figure) are arranged side by side in region 11, and the second set of reverse bends 23 (at the top of the figure) are arranged side by side in region 12. The second set of reverse bends 23 is formed in the connecting element 30, and the pipe segment 21 extends from the connecting element 30 in region 12 to region 11. This specific arrangement is not mandatory.

[0111] Within the scope of this invention, the use of connecting element 30 is optional but advantageous. On the other hand, the embodiments of the invention explained below specifically relate to the design of a device for feeding current into region 11, hence the region is referred to as the current feeding region. This is achieved by using a power feeding assembly 40, which is shown here in a highly simplified manner, and only one of them is shown.

[0112] Figure 3 A reactor for performing a chemical reaction according to an embodiment of the present invention is schematically shown, the reactor being indicated by 200.

[0113] In reactor 200, each of the pipe segments, denoted herein by 22, comprises a plurality of pipe segments 22 of reaction tubes 20, wherein the pipe segments 22 are arranged side by side in the reaction vessel 10 in a manner in which they are not fluidly connected to each other, and each is connected to a feed section 24 and an extraction section 25 for the working fluid. For the remaining components, refer specifically to the above description relating to the foregoing figures.

[0114] Again, in the context of this invention, the use of connector 30 is optional but advantageous. Power supply assembly 40 is also shown here in a highly simplified manner. Power supply assembly 40 may have a sleeve-shaped region 49 disposed around the reaction tube 20 or tube segment in region 11.

[0115] Figure 4 Examples are shown, such as Figure 2 The diagram shows a cross-sectional view of region 11 of reactor 100, in which power supply assembly 40 is arranged in region 11 and reaction tube 20 is connected to power supply assembly 40, wherein the tube segments 21 of the reaction tube 20, shown in a multi-segment form, converge with each other via reverse bends 23.

[0116] A reinforcing wall is formed at the reverse bend 23, which is adjacent to two pipe segments 21 in region 11. One wall of the reverse bend 23 is connected to or integrally formed with the first portion 41 of the power supply assembly 40, which has been schematically shown previously.

[0117] Each power supply assembly 40 includes a first portion 41 and a second portion 42, wherein the first portion 41 originates here from two pipe segments 21 or reverse bends 23 extending along the longitudinal axis A. In the region of the power supply assembly 40, the first portion 41 sleeves around the second portion 42, and the first portion 41 and the second portion 42 have contact surfaces 41a, 42a, which are inclined relative to the longitudinal axis A for mutual contact.

[0118] The contact surfaces 41a and 42a of the first portion 41 and the second portion 42 of the power supply assembly 40 are each formed as a conical inner surface and a conical outer surface, respectively, which can be brought into contact with each other by pushing or bringing the first portion 41 and the second portion 42 of the power supply assembly 40 together. More precisely, in the example shown, the contact surfaces 41a and 42a are formed as the inner and outer surfaces of a conical shell with a 60° cone angle.

[0119] Each of the power supply assemblies 40 extends through the wall 14 of the reactor vessel 10 at a wall channel 15 and is housed therefor longitudinal movement. The wall channel 15 is shown here in enlarged width and is lined, for example, with an insulating material shown as shaded.

[0120] Optionally, but not essential to the present invention, a bellows device (not shown) may be provided on the outside of the wall 14 of the reactor vessel 10 to ensure the reactor vessel 10 is airtight to the environment when the rod-shaped power feed assembly 40 moves longitudinally.

[0121] The busbar or strand can be attached to one end 42b of the second part 42 to connect the phase U, V, W or corresponding current wiring of a DC current source or a single-phase AC current source.

[0122] Figure 5 A cross-sectional view of the current feed region 11 of the reactor 100 is shown, in which it has been combined Figure 4 The components shown in each case are explained. However, with Figure 4 Unlike other designs, reaction pipe 20 here has no reverse bend, and pipe segment 21 is arranged along a common central axis M. The unbent transition area is marked 23a. For example, a corresponding design can be used instead of the one based on... Figure 3 The sleeve in the reactor 200 shown. Here, the transition region 23a is also formed with a reinforcing wall, to which the first part 41 of the power supply assembly 11 is connected. Further explanation can be found in [reference needed]. Figure 4 .

[0123] Figure 6A and Figure 6B A longitudinal section is shown passing through the power feeding assembly 40 according to an embodiment of the invention, along two sections perpendicular to each other.

[0124] like Figure 6A As shown, a spring-type elastically deformable biasing element 44 is provided, which pushes the second part 42 of the power supply assembly 40 along the longitudinal axis A in the direction of the first part 41 and is supported in the housing 44a. Furthermore, the second part 42 of the power supply assembly 40 is provided with a surface enlargement element 45 in the form of cooling fins.

[0125] In the cracking furnace, in addition to the previously... Figure 1 and Figure 2 In addition to the reaction tube 20 shown, a less-channel variant can also be used, wherein the reaction tube 20 is typically referred to as a 6-channel coil and has six straight tube sections 21, which together have five 180° bends.

[0126] For example, a so-called 2-channel coil only has two straight pipe sections 21 and one 180° bend or reverse bend 23. This is in Figures 7A to 7C The following is illustrated. In each case, current injection can occur at a point in each reaction tube 20 at the lower (or only) reverse bend. Each of the M reaction tubes can be electrically interconnected with a phase shift of 360° / M using a common connecting element 30. In this case, in the first alternative, a particularly large connecting element 30 can be used for each coil package or for all reaction tubes 20 considered in each case. However, in the second alternative, two smaller connecting elements 30 can also be used.

[0127] Figure 7B The cross-sectional view of pipe segment 21 illustrates the first alternative just described, and Figure 7C The cross-sectional view through pipe section 21 illustrates the second alternative just described, in which the corresponding reaction tube 20 is... Figure 7A The middle is perpendicular to Figure 7B and Figure 7C The view is shown in view form. For the labeling of the corresponding elements, please refer to [reference needed]. Figure 1 It should be understood that, via the power supply assembly 40 (shown here in a highly simplified manner), one or more connecting elements 30 are arranged in different planes corresponding to regions 11 and 12 of the reactor, wherein the connecting element 30 has, on the one hand, a reverse bend 23 that may be provided on the connecting element, and on the other hand, other reverse bends 23 that connect to phases U, V, and W. It should be emphasized again that, in the context of this invention, the presence and arrangement of the connecting elements 30 are purely optional or arbitrary.

[0128] Therefore, the concept can also be applied to coils or reaction tubes 20 with four channels or sections 21 (so-called four-channel coils), in which case there are one, two, or four star-shaped bridges or connecting elements 30. Figure 8A and Figure 8B The corresponding example is shown in the figure, where Figure 8B Four connecting elements 30 are shown. For better illustration, the reverse bend 23 is shown here with dashed lines (reverse bend in area 12) and solid lines (reverse bend in area 11). For clarity, only parts of the elements are labeled with reference numerals.

[0129] Figures 9A to 9C Additional reaction tubes used in a reactor according to an embodiment of the invention are shown. The reaction tubes and sections are only partially labeled with reference numerals here. The feed section and extraction section are indicated by the flow arrows shown. The power feed assembly 40 may appear multiple times and may be designed in the manner described above, and is shown as a highly simplified dashed line.

Claims

1. A reactor (100, 200) for performing a chemical reaction, the reactor (100, 200) having a reactor vessel (10) and one or more reaction tubes (20), a plurality of tube segments (21, 22) of the one or more reaction tubes (20) extending inside the reactor vessel, and the tube segments (21, 22) being electrically connected to or capable of being electrically connected to one or more current wirings in a current feeding region (11) to electrically heat the tube segments, characterized in that, A power supply assembly (40) is disposed in the current supply region (11), and one or a group of the pipe segments (21, 22) is electrically connected to the power supply assembly (40). Each power supply assembly (40) has a first portion (41) and a second portion (42). The first portion (41) extends along a longitudinal axis (A) from an element of the corresponding pipe segment (21, 22), or the corresponding group of pipe segments (21, 22), or connected to the corresponding pipe segment (21, 22) or the corresponding group of pipe segments (21, 22). In the region of the power feeding assembly (40), the first portion (41) at least partially surrounds the second portion (42) in a sleeve-like manner or the second portion (42) at least partially surrounds the first portion (41) in a sleeve-like manner, the first portion (41) and the second portion (42) having contact surfaces (41a, 42a) that are inclined relative to the longitudinal axis (A) for mutual contact, and each of the power feeding assemblies (40) extends through the wall (14) of the reactor vessel (10) at the wall channel (15).

2. The reactor (100, 200) according to claim 1, wherein, Material connection is provided between the first portion (41) of the power feeding assembly (40) and the corresponding pipe segment (21, 22) or the group of corresponding pipe segments (21, 22), or wherein, The first portion (41) of the power supply assembly (40) and the corresponding pipe segment (21, 22) are integrally formed.

3. The reactor (100, 200) according to claim 1 or 2, wherein, The contact surfaces (41a, 42a) of the first portion (41) and the second portion (42) of the power feeding assembly (40) are formed into a conical inner surface and a conical outer surface, which can be brought into contact with each other by pushing or pushing the first portion (41) and the second portion (42) of the power feeding assembly (40) together.

4. The reactor (100, 200) according to claim 1 or 2, wherein, The contact surfaces (41a, 42a) are formed as the inner and outer surfaces of a conical shell, or as the inner and outer surfaces of a conical shell with a truncated cone shape.

5. The reactor (100, 200) according to claim 4, wherein, The contact surface includes a cone angle of 40° to 120°.

6. The reactor (100, 200) according to claim 4, wherein, A biasing element (44) capable of elastic deformation is provided, which pushes the second part (42) of the power feeding assembly (40) toward the first part (41) along the longitudinal axis (A).

7. The reactor (100, 200) according to claim 1 or 2, wherein, The contact surfaces (41a, 42a) are formed as threaded surfaces.

8. The reactor (100, 200) according to claim 1 or 2, wherein, The second part (42) of the power feeding assembly (40) is provided with a surface enlargement element (45) and / or connected to the surface enlargement element (45).

9. The reactor (100, 200) according to claim 1 or 2, wherein, The power supply components (40) are each capable of moving longitudinally through the wall (14) of the reactor vessel (10) in their respective wall channels (15).

10. The reactor (100, 200) according to claim 1 or 2, wherein, The power supply assembly (40) outside the reactor vessel (10) is electrically connected to or can be electrically connected to the power terminal of the power source (50) by means of a flexible connecting element.

11. The reactor (100) according to claim 1 or 2, wherein, The one or more reaction tubes (20) include one or more reverse bends (23) in the reactor vessel (10).

12. The reactor (200) according to claim 1 or 2, wherein, Without the reverse bend (23), multiple reaction tubes (22) extend in the reactor vessel (10).

13. The reactor (100) according to claim 11, wherein, The reactor (100) is designed as a reactor (100) for steam cracking.

14. The reactor (200) according to claim 12, wherein, The reactor (200) is designed as a reactor (200) for steam reforming, dry reforming, or catalytic dehydrogenation of alkanes.

15. The reactor (100, 200) according to claim 1 or 2, wherein, The second part (42) is formed of a material composed of a single metal or metal alloy selected from molybdenum, tungsten, tantalum, niobium, and chromium, wherein the metal alloy contains at least 50% by weight of at least one material selected from the group consisting of molybdenum, tungsten, tantalum, niobium, nickel, and chromium.

16. A method for performing a chemical reaction using a reactor (100, 200), said reactor (100, 200) having a reactor vessel (10) and one or more reaction tubes (20), wherein, Multiple tube segments (21, 22) of the one or more reaction tubes (20) extend in the reactor vessel, and each of the tube segments (21, 22) is electrically connected to or can be electrically connected to one or more current wirings in a current feeding region (11) to electrically heat the tube segment, characterized in that, using the reactor (100, 200), in the reactor (100, 200), a power feeding assembly (40) is disposed in the current feeding region (11), one of the tube segments (21, 22) or a group of the tube segments (21, 22) is electrically connected to each of the power feeding assemblies (40), each of the power feeding assemblies (40) having a first portion (41) and a second portion (42), the first portion (41) being from the corresponding tube segment (21, 22), or a... The corresponding group of pipe segments (21, 22), or the element connected to the corresponding group of pipe segments (21, 22) or the corresponding group of pipe segments (21, 22) extends along the longitudinal axis (A). In the region of each of the power feeding assemblies (40), the first portion (41) at least partially surrounds the second portion (42) in a sleeve-like manner, or the second portion (42) at least partially surrounds the first portion (41) in a sleeve-like manner. The first portion (41) and the second portion (42) have contact surfaces (41a, 42a) that are inclined relative to the longitudinal axis (A) for mutual contact. Each of the power feeding assemblies (40) extends through the wall (14) of the reactor vessel (10) at the wall channel (15).

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