Reactor for carrying out exothermic reactions, and use and method for operating such a reactor

Abstract

The present invention relates to a reactor (1) comprising: a plate heat exchanger (2) having a plurality of adjacent plates (3) between which gap channels (4, 5) are defined, said gap channels (4, 5) being divided into a plurality of fluidically interconnected primary gap channels (4) and a plurality of fluidically interconnected secondary gap channels (5), wherein a catalyst material (6) for an exothermic reaction is provided in at least one of the primary gap channels (4), and wherein primary fluid supply means (7) for supplying a primary fluid to the primary gap channels (4) and secondary fluid supply means (10) for supplying a secondary fluid to the secondary gap channels (5) are provided; a pressure vessel (18) that encloses the plate heat exchanger (2); and pressure fluid supply means (19) that are designed to supply a pressure fluid to the pressure vessel (18).

Description

Reactor for carrying out exothermic reactions, and use and method for Operating such a reactor The invention relates to a reactor for carrying out exothermic reactions. Furthermore, the invention relates to the use of, and a method for operating such a reactor. The applicant is aware that various designs are used for heat-transfer devices. The purpose of such devices is to transfer heat from a hot side (heat source) to a cold side (heat sink). In the simplest case, heat sources and sinks can be heat transfer fluids, such as water (steam) or thermal oil. Specifically, heat sinks can be endothermic reactions and heat sources can be exothermic reactions. Specific examples of heat sinks include catalyzed endothermic reactions. The applicant is aware that the following reactor types are sometimes used for such applications: - Heated tube-bundle reactors - Adiabatic beds with intermediate heating (batch reactor) - Heated fluidized bed reactors Plate reactors are also known from the prior art. These offer the advantage of a large heat transfer surface area. However, particularly due to their rectangular shape, they are only moderately pressure-stable. Chemical reactions, such as endothermic reactions, often proceed under excess pressure, which can pose a major challenge to the reactors used. Examples of endothermic reactions that proceed under excess pressure, along with the reactor types used to the applicant’s knowledge, include: - Ammonia cracking - batch and tube-bundle reactors - Methane steam reforming -tube-bundle reactor - Methanol steam reforming -tube-bundle reactor - Propane and butane dehydrogenation (Oleflex) - batch reactor The aforementioned reactor designs all have disadvantages. In the case of adiabatic beds with intermediate cooling, the catalyst beds typically become very large because the catalyst is not utilized efficiently. In addition, a comparatively large amount of equipment is required for the intermediate heat exchangers used. Although heated tube-bundle reactors offer comparatively good catalyst utilization, they are generally very expensive because their cost scales with the number of tubes. In the field of electrolysis and fuel cell technology, electrolysis and fuel cell stacks arranged within a pressure vessel are known. For example, a high-pressure electrolysis cell is described in JP 5 524 227 B2. US 6 153 083 A discloses an electrolyzer for the electrolysis of water into hydrogen and oxygen, comprising a number of electrolytic cells, each containing one anode and one cathode, which are connected in series within a cell block enclosed by a pressure vessel. US 6 689 499 B2 discloses pressurized fuel cell generator modules protected by purge gas. JP 3 845 780 B2 discloses both atmospheric and pressurized SOFC power generation systems. It is therefore an objective of the present invention to provide an alternative reactor for carrying out exothermic reactions, which avoids or at least reduces the aforementioned disadvantages and can be manufactured with comparatively little effort. It is further an objective of the invention to provide a method for operating such a reactor. The first-mentioned objective is solved by the invention through a reactor for carrying out exothermic reactions, comprising -     a plate heat exchanger having a plurality of adjacent plates, in par ticular plates oriented at least substantially parallel to one another, between which gap channels are defined, wherein the gap channels are subdivided into several primary gap channels that are fluidically connected, in particular fluidically connected in parallel, and several secondary gap channels that are fluidically connected, in particular fluidically connected in parallel, wherein in at least one of the primary gap channels, preferably in all primary gap channel, a catalyst material for an exothermic reaction, in particular for a catalytic oxidation reaction, preferably for a catalytic oxidation reaction of hydrogen, and most preferably for a catalytic combustion of hydrogen with oxygen, is provided, and wherein primary fluid supply means are provided for supplying a primary fluid to the primary gap channels and secondary fluid supply means are provided for supplying a secondary fluid to the secondary gap channels, -     a pressure vessel surrounding the plate heat exchanger, -     pressure fluid supply means configured to supply a pressure fluid to the pressure vessel and, in particular, to generate an elevated pressure of at least 2 bar, in particular of at least 5 bar, preferably of at least 10 bar, and most preferably of at least 20 bar, within the pressure vessel. The second-mentioned objective is solved according to the invention by a method for operating a reactor according to the invention, comprising the steps - a primary fluid is supplied to at least one primary gap channel, preferably all primary gap channels, and in the at least one primary gap channel, preferably in all primary gap channels, an exothermic reaction, in particular an oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, is carried out, - a secondary fluid is supplied to at least one secondary gap channel, preferably to all secondary gap channels, - a pressure fluid, in particular a pressure gas, is supplied to the pressure vessel, preferably, wherein the pressure fluid comprises N2 and / or liquid water and / or water vapor and / or air, or is provided thereby. - In other words, the present invention proposes the use of a plate heat exchanger to carry out chemical reactions. A plate heat exchanger comprises, in a manner well known in the art, a plurality of plates, wherein a gap channel is formed between each pair of adjacent plates. The gap channels are typically divided into two groups, and the gap channels of one group usually alternate with those of the other group. The two groups of gap channels are separated from one another in terms of fluid flow but are thermally coupled to one another. In conventional operation of a plate heat exchanger, for example, a heat transfer fluid flows through the gap channels of both groups, and an efficient exchange of thermal energy takes place between the heat transfer fluids. According to the invention, selected gap channels, in particular, at least one group of gap channels, are used to carry out or operate an exothermic reaction therein. These gap channels intended for or used in the exothermic reaction are referred to herein as primary gap channels. According to the invention, a catalyst material is provided in the primary gap channels, in particular one suitable for an oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen. A primary fluid is supplied to the primary gap channels for the reaction. This can also be referred to as a reaction fluid. The other group of gap channels, referred to herein as secondary gap channels, can be used, for example, to dissipate heat released during the exothermic reaction. In this configuration, one can also say that the primary gap channels serve as reaction gap channels and the secondary gap channels serve as cooling gap channels. A secondary fluid is supplied to the secondary gap channels. If this fluid is used for heat removal, the secondary fluid can be said to serve as a cooling medium. It may be a “classic” heat transfer fluid, such as water or thermal oil, which is heated by the heat from the exothermic oxidation reaction. For example, water can be heated to saturated steam or superheated steam. It is also possible to use the heat from the exothermic oxidation reaction on the primary side to drive an endothermic reaction on the secondary side, or to achieve cooling via an endothermic reaction on the secondary side. Optionally, a catalyst material may therefore also be provided in the secondary gap channels. A catalyst material that may be present in the secondary gap channels, which, for the sake of distinction, may also be referred to as “secondary catalyst material”, may differ from the catalyst material in the primary gap channels. Within the scope of the present invention, various exothermic and endothermic reactions can be combined with one another. Alternatively or additionally, secondary gap channels can be used as heating / cooling channels and can be flowed through by a heat transfer fluid for this purpose. The reactor according to the invention is, in particular, a thermocatalytic reactor. The reactor of the invention is not an electrolytic reactor. In other words, it is not a reactor in which electrical current-driven chemical reactions—in particular, redox reactions forced by electrical energy—can occur or do occur. Accordingly, within the scope of the method of the invention, no electrolytic reactions are carried out in the primary or secondary gap channels. Preferably, the primary gap channels and the secondary gap channels are not fluidically connected to one another. It has also proven particularly advantageous in the reactor according to the invention for the primary gap channels and the secondary gap channels to be arranged alternately; in other words, for a primary gap channel to alternate with a secondary gap channel. This allows, for example, particularly efficient cooling of an exothermic reaction on the primary side. The invention further provides that the plate heat exchanger is installed in a pressure vessel in which an elevated pressure exists or can be achieved during operation. The plate heat exchanger is arranged within the interior of the pressure vessel, making it possible that no or only a small pressure difference to the outside—in other words, relative to the pressurized interior of the pressure vessel—exists during operation. The plate heat exchanger can therefore be designed with a relatively simple construction. High pressures and temperatures can prevail in the secondary gap channels and / or the primary gap channels during operation without requiring complex sealing of the plate heat exchanger or the secondary and / or primary gap channels. In particular, the pressure in the pressure vessel and on the high-pressure side of the plate heat exchanger—which may specifically be the secondary side—may be at least approximately equal during operation. It should be noted that it is also not excluded that a reactor according to the invention may comprise more than one plate heat exchanger arranged within the pressure vessel. The present invention combines various advantages. On the one hand, the reactor according to the invention can be manufactured at a comparatively low cost. At the same time, it offers a high degree of safety. It also provides good heat integration, particularly in comparison with adiabatic beds with intermediate cooling. There is a high degree of load flexibility, and rapid load changes are also possible. This is particularly true because cooling can be used instead of adiabatic beds. Furthermore, the reactor according to the invention can also be started up relatively quickly. For example, the secondary fluid can also be used for preheating or heating during a startup phase, as will be discussed in more detail below. In a preferred embodiment, the pressure vessel has an at least substantially cylindrical, in particular circular-cylindrical, shape. It may comprise a (circular) hollow cylindrical shell that is closed at both ends. It may have rounded, in particular outwardly convex, ends or end walls, which has proven to be a particularly advantageous shape for pressure vessels. A cylindrical pressure vessel with rounded, outwardly curved end faces can represent a good compromise between the ideal shape of a spherical shell, on the one hand, and comparatively simple, cost-effective manufacturing while still providing very good compressive strength, on the other hand. The pressure vessel is preferably designed to be explosion-proof, so that a particularly high level of safety can be achieved. The pressure vessel may be provided on the inside with an insulating layer made of a thermally insulating material. Examples of thermally insulating materials include fireclay bricks, glass fabric, and / or ceramic fabric, such as polycrystalline mullite / alumina wool (PCW). Alternatively or additionally, the pressure vessel may comprise steel, in particular a steel outer shell. If the pressure vessel comprises an internal thermal insulating layer, this prevents its outer shell from heating up to high temperatures during operation. This enables to provide an outer shell even from materials with lower temperature resistance, in particular one made of cost-effective steels that can withstand, for example, temperatures of up to 250°C, preferably up to 220°C, and most preferably up to 100°C. A leak sensor may also be provided for monitoring the plate heat exchanger. The plate heat exchanger can be monitored for leaks using a leak sensor. The leak sensor for monitoring the plate heat exchanger is preferably located inside the pressure vessel. If the pressure vessel is filled with an inert gas, it is appropriate to monitor for a component from the plate heat exchanger that is dissimilar to the inert gas. For example, if the pressure vessel is filled with dry air or nitrogen, and high-pressure steam is generated on the secondary side of the plate heat exchanger, the moisture content in the pressure vessel can be monitored. For example, if endothermic methanol steam reforming is taking place and N2 is supplied to the pressure vessel as a pressurizing gas, in other words, if the vessel is purged with N2, the leakage sensor is suitably used to test for or monitor H2, CO2, or H2O. In principle, various catalyst materials can be used within the scope of the present invention. The catalyst material provided in the primary gap channel(s) may, for example, comprise at least one noble metal, in particular platinum and / or palladium, preferably platinum provided on a metal oxide support, in particular platinum provided on an aluminium oxide support. As noted, a catalyst material for an endothermic reaction, in particular a catalyst material for a hydrogen release reaction, specifically for NH3 cracking or methanol dehydrogenation, methanol reforming, DME reforming, methane steam reforming, LPG reforming, or butane or propane dehydrogenation, may be provided in at least one of the secondary gap channels. If a catalyst material is also provided in the secondary gap channels, it may comprise, for example, copper and / or palladium and / or zinc. The catalyst material provided in the primary gap channel(s) and a catalyst material possibly provided in the secondary gap channels may also be supported on a carrier material. The (respective) catalyst material or its support material may, for example, be granular. It may be in the form of pellets, or pellets comprising the catalyst material may be provided in the primary gap channels. Alternatively or additionally, the catalyst material may also be present in the form of at least one coating, obtained, for example, by a washcoat process. For example, plates of the plate heat exchanger may be coated with the catalyst material or with a coating material comprising the catalyst material. One or more insert plates may also be positioned in the primary gap channels and / or in the secondary gap channels, which consist of the catalyst material or are coated with the catalyst material, for example, via a washcoat, which can simplify manufacturing. It is also possible for the catalyst material to be present in the form of catalytically active structures. By way of example, catalytically active networks may be provided in the primary gap channels and / or in the secondary gap channels. In a particularly preferred embodiment, a catalytic oxidation reaction is carried out in the primary gap channel(s). An oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, may be carried out. Accordingly, in a preferred embodiment, the primary gap channel(s) comprise a catalyst material for such a reaction. The following may apply: H2(g) + ½ O2(g) -> H2O(g)    A H° = -242 kJ mol-1 A combustion mixture comprising a gaseous fuel and a gaseous oxidizing agent can be supplied to the at least one primary gap channel as a primary fluid. In a particularly advantageous embodiment, catalytic oxidation of hydrogen takes place under the conditions described in DE 10 2023 200 245 B3. In particular, a primary fluid comprising or consisting of a mixture of hydrogen and oxygen is supplied to the at least one primary gap channel, preferably such that the primary fluid supplied is outside the explosive range. The oxygen concentration of the primary fluid is advantageously below the oxygen limit concentration. The explosive range is the range of mixing ratios of the primary fluid’s components within which the primary fluid is explosive. The primary fluid is preferably outside the explosive range; in particular, the oxygen concentration of the primary fluid is below the limiting oxygen concentration. The limiting oxygen concentration specifies the oxygen content below which a total mixture is no longer explosive. There is not enough oxygen present to enable an explosion. Thus, a flame independent of the ignition source can no longer propagate on its own. In particular, an explosive primary fluid is not present at any point in the method according to the invention. How this is achieved in terms of process engineering can be found in DE 10 2023 200 245 B3. In this way, the technical effort can be significantly reduced. At the same time, safety can be ensured in a simple and effective manner. Additionally, the combustion process is particularly efficient. Furthermore, no NOx emissions are produced. In an advantageous configuration water can be heated to saturated steam or superheated steam by means of the exothermic reaction taking place in the primary gap channels, in particular, by the catalytic oxidation reaction of hydrogen. In this case, liquid water is fed into the secondary gap channels as the secondary fluid and is vaporized by absorbing heat from the exothermic reaction taking place in the primary gap channels, such as the catalytic oxidation of hydrogen. For example, a pressure of 165 bar may be present in the secondary gap channels, and liquid water at 340°C may be supplied to the secondary gap channels as the secondary fluid. The pressure vessel then preferably maintains at least a similar pressure, in particular also a pressure of 165 bar. In the primary gap channels, such a pressure, or another pressure, such as atmospheric pressure, may also be present. It is also possible for a retentate stream, originating in particular from product processing, to be used as the primary fluid or to be a component of the primary fluid. In a further preferred embodiment, it may be provided that a primary fluid comprising a retentate or a retentate stream, originating in particular from product processing, is supplied to the at least one primary gap channel. Another preferred embodiment is characterized in that methanol reforming is carried out in the at least one secondary gap channel and a catalytic oxidation reaction of a portion of the product stream exiting the at least one secondary gap channel is carried out in the at least one primary gap channel. This combination of an endothermic reaction on the secondary side and an exothermic reaction on the primary side has proven to be particularly suitable in the context of the present invention. In particular, the following may apply: CH3OH + H2O -> CO2 + 3 H2 A H° = +49.7 kJ mol-1 The secondary gap channels, in which methanol reforming takes place, then contain a methanol reforming catalyst comprising or consisting of, for example, Cu or Pd / Zn. Catalytic oxidation takes place in the primary gap channels for heating purposes. A portion of the product stream is primarily used for this purpose; this stream consists mainly of hydrogen (and CO2) and contains smaller amounts of methanol, H2O, and CO. The hydrogen, as a valuable byproduct, can be further utilized, for example, in chemical reactions for steel production or for electricity generation. Typically, a separation process takes place, such as membrane separation or pressure-swing adsorption, which yields a retentate (low in hydrogen, rich in CO2) and a permeate (rich in hydrogen). The hydrogen-rich permeate serves as a valuable product. The retentate still contains oxidizable substances (hydrogen, CO, methanol) that can be used for heating. Preferably, the retentate or a portion of the retentate is used for heating. In other words, it may be provided that the retentate from a separation process of the product stream, for example, from membrane separation or pressure-swing adsorption, is supplied to the at least one primary gap channel as the primary fluid or as a component of the primary fluid. It is further preferred that oxidizable species, in particular hydrogen and / or methanol and / or CO, are oxidized with an oxidizing agent, such as atmospheric oxygen, to form CO2, thereby providing the heat required for the endothermic reaction on the secondary side. For the combination of methanol reforming (endothermic, secondary side) and catalytic oxidation reaction (exothermic, primary side), it is preferred that a pressure of up to 25 bar prevails in the pressure vessel (similar to the methanol reforming pressure in the secondary gap channels). The reactor according to the invention may comprise pressure control means that are embodied and / or configured such that the pressure difference that exists during operation of the reactor between the pressure in the pressure vessel and the pressure in at least one of the secondary gap channels, preferably in all secondary gap channels, can be controlled, preferably regulated with the pressure control means. In a preferred embodiment of the method according to the invention, the reactor is operated such that the pressure in the pressure vessel is at most 20%, in particular at most 10%, preferably at most 5%, and most preferably at most 1% above or below the pressure in at least one of the secondary gap channels, preferably in all secondary gap channels, which has proven to be particularly suitable. Alternatively or additionally, the reactor may be operated such that the pressure in the pressure vessel is at most 5 bar, in particular at most 1 bar, preferably at most 100 mbar, above or below the pressure in at least one of the secondary gap channels, preferably in all secondary gap channels. In other words, when setting or controlling a maximum pressure difference between the interior of the pressure vessel and the pressure in one or more secondary gap channels, the control may be based on a percentage difference and / or absolute deviations. Pressure control means of the reactor according to the invention may be embodied and / or configured to achieve this. In other words, the pressure inside the pressure vessel is then equal to or at least similar to the pressure in one or more secondary gap channels. To achieve this, the pressure of the pressurized gas can, for example, be adjusted during operation to match the pressure in the secondary gap chan-nel(s). The pressure control means may be embodied and / or configured accordingly. If pressure control means are present, these may alternatively or additionally be embodied and / or configured such that the pressure difference, which, during operation of the reactor, exists between the pressure in at least one of the primary gap channels (preferably in all primary gap channels) and the pressure in at least one of the secondary gap channels (preferably in all secondary gap channels), can be controlled, preferably regulated. The reactor can also be operated such that the pressure in at least one of the secondary gap channels, preferably the pressure in all secondary gap channels, is maintained at most 20%, in particular by a maximum of 10%, preferably by a maximum of 5%, and most preferably by a maximum of 1%, above or below the pressure in at least one of the primary gap channels, preferably in all primary gap channels. Alternatively or additionally, the reactor can be operated such that the pressure in at least one of the secondary channels, preferably the pressure in all secondary gap channels, is at most 5 bar, in particular at most 1 bar, preferably at most 100 mbar, above or below the pressure in at least one of the primary gap channels, preferably in all primary gap channels. Pressure control means of the reactor according to the invention may be embodied and / or configured to achieve this. In other words, operation may also be carried out such that the secondary gap channels have the same or similar pressure as the primary gap channels. However, a pressure difference may also exist, and (significantly) different pressures are also possible in principle. The secondary gap channels and / or the primary gap channels, or the plates defining the secondary gap channels and / or the plates defining the primary gap channels, may then, in particular, be welded together, or suitable seals and sufficient contact pressure between the plates may be provided to accommodate even higher pressure differentials. It may also be provided that the primary gap channels and / or the secondary gap channels are equipped with stabilizing elements, in particular stabilizing ribs. The stabilizing elements can increase stability. Particularly for applications in which larger pressure differentials between the primary and secondary gap channels (may) occur, it can be advantageous to reinforce the gap channels accordingly. Stabilizing elements, for example in the form of stabilizing ribs, can extend between two adjacent plates and be supported by the adjacent plates. In the event that a larger pressure difference between the primary and secondary gap channels occurs during operation or is anticipated, such as a pressure difference of more than 5 bar, or, if necessary, significantly more than 5 bar, the sealing of the plate heat exchanger can be specifically embodied such that the side with higher pressure (primary or secondary side) keeps the side with lower pressure (secondary or primary side) sealed during operation. In particular, sealing elements of the plate heat exchanger can be specifically arranged accordingly. For example, such that during operation, due to the higher pressure on one side (primary or secondary), at least one element, such as a plate of the plate heat exchanger, is pressed against at least one other element of the plate heat exchanger. In a further advantageous embodiment, a control device is provided by means of which the pressure in the pressure vessel and / or the pressure difference between the pressure in the pressure vessel and the pressure in at least one of the secondary gap channels can be controlled, preferably regulated. Alternatively or additionally, the control device may be used to set, and preferably regulate, the pressure in the primary gap channels. Usually, the pressure in the secondary gap channel(s) and the pressure in the secondary fluid supply to the secondary gap channels and / or in the secondary fluid discharge from the secondary gap channels are nearly identical. This applies in particular when no valve or similar device is arranged between the plate heat exchanger or its secondary gap channels and at least one supply or discharge pipe. The same applies with regard to the primary gap channels and the pressure vessel, as well as at least one supply or discharge pipe in each case. Here, too, the pressure is nearly identical, particularly when no valve or similar device is arranged between the primary gap channels or the pressure vessel and a supply or discharge pipe. Accordingly, the optionally provided pressure control means may be embodied and / or configured such that they can be used to control, and preferably regulate, the pressure difference that, during operation of the device, exists between, on the one hand, the pressure in the pressure vessel and / or the pressure in at least one pipe upstream or downstream of the pressure vessel, and, on the other hand, the pressure in at least one of the secondary gap channels, preferably in all secondary gap channels, and / or in at least one pipe upstream or downstream of the secondary gap channels, on the other hand, can be controlled, preferably regulated. A pressure measuring device may also be provided for measuring the pressure in the pressure vessel and / or in at least one, preferably exactly one, pipe upstream of the pressure vessel. Alternatively or additionally, a pressure measuring device may be provided for measuring the pressure in at least one, preferably exactly one, pipe downstream of the pressure vessel. This may, for example, be a pressure measuring device for measuring the pressure in a pressure inlet pipe and / or for measuring the pressure in a pressure outlet pipe, through which pressure fluid can be supplied to or discharged from the pressure vessel. Furthermore, at least one secondary pressure measuring device may be provided for measuring the pressure in one, or even several, or possibly all, secondary gap channels. Alternatively or additionally, a secondary pressure measuring device may be provided for measuring the pressure in at least one, preferably exactly one, pipe upstream of the secondary gap channels and / or the pressure in at least one, preferably exactly one, pipe downstream of the secondary gap channels. Alternatively or additionally, the reactor according to the invention may comprise a secondary differential pressure measuring device for measuring the pressure difference between the pressure in the pressure vessel and / or in at least one, preferably exactly one, pipe upstream of the pressure vessel and the pressure in at least one of the secondary gap channels. If a secondary differential pressure measuring device is present, it may be embodied, either alternatively or in addition, to measure the pressure difference between the pressure in the pressure vessel and / or in at least one pipe upstream of it, on the one hand, and the pressure in at least one pipe upstream of the secondary gap channels and / or in at least one pipe downstream of the secondary gap channels, on the other hand. At least one primary pressure measuring device may also be provided for measuring the pressure in one, or even several, or possibly all, primary gap channels. Alternatively or additionally, a primary pressure measuring device may be provided for measuring the pressure in at least one, preferably exactly one, pipe upstream of the primary gap channels and / or the pressure in at least one, preferably exactly one, pipe downstream of the primary gap channels. Alternatively or additionally, the reactor according to the invention may comprise a primary differential pressure measuring device for measuring the pressure difference between the pressure in the pressure vessel and / or in at least one pipe upstream of the pressure vessel and / or in at least one pipe downstream of the pressure vessel, on the one hand, and the pressure in at least one of the primary gap channels, on the other hand. If a primary differential pressure measuring device is present, it may be embodied, either alternatively or in addition, to measure the pressure difference between the pressure in the pressure vessel or in at least one pipe upstream of it and / or in at least one pipe downstream of it, on the one hand, and the pressure in at least one pipe upstream of the primary gap channels and / or in at least one pipe downstream of the primary gap channels, on the other hand. The pipe upstream of the secondary gap channel(s), in which the pressure can be measured either alternatively or additionally, may be, for example, a secondary inlet pipe and / or a secondary distribution channel or one of several branches of a secondary distribution channel. The pipe is fluidically upstream of the secondary gap channel(s) and may be connected directly to one or more of the secondary gap channels, or via one or more additional pipes. Similarly, the pipe located downstream of the secondary gap channel(s), in which the pressure can be measured either alternatively or additionally, may, for example, be a secondary outlet pipe and / or a secondary collector channel, or one of several branches of a secondary collector channel. The pipe is fluidically downstream of the secondary gap channel(s) and may be connected directly to one or more of the secondary gap channels, or via one or more additional pipes. Furthermore, the line upstream of the primary gap channels, in which the pressure can be measured either alternatively or additionally, may, for example, be a primary inlet line and / or a primary distributor channel or one of several branches of a primary distributor channel. ’s line is fluidically upstream of the primary gap channel(s) and may be connected directly to one or more of the primary gap channels, or via one or more additional lines. The line located downstream of the primary gap channels, in which pressure can be measured either alternatively or additionally, may be, for example, a primary outlet line and / or a primary collector channel or one of several branches of a primary collector channel. The line is fluidically downstream of the primary gap channel(s) and may be connected directly to one or more of the primary gap channels, or via one or more additional lines. The pipe upstream of the pressure vessel may, for example, be a pressure inlet pipe, and the pipe downstream of the pressure vessel may, for example, be a pressure outlet pipe. The pressure measuring device and / or the secondary pressure measuring device and / or the primary pressure measuring device and / or the secondary differential pressure measuring device and / or the primary differential pressure measuring device may be part of the reactor's pressure control system. A control device of the pressure control means may also be connected to the pressure measuring device and / or the secondary pressure measuring device and / or the primary pressure measuring device and / or the secondary differential pressure measuring device and / or the primary differential pressure measuring device. Depending on the measured pressure (differential) values, for example, at least one valve and / or at least one pump and / or at least one compressor can be controlled to achieve the desired pressure conditions. The pressure fluid supply means, which may comprise at least one valve and / or at least one pump and / or at least one compressor, may also be connected to the pressure control means, in particular a control device thereof. It has also proven particularly advantageous when the pressure control means, in particular a control device thereof, are embodied and / or configured such that the pressure in the pressure vessel and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the pressure vessel can be controlled, in particular regulated, as a function of the pressure in at least one of the secondary gap channels and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the secondary gap channels. Alternatively or additionally, it may be provided that the pressure control means, in particular a control device thereof, are embodied and / or configured such that the pressure in the pressure vessel and / or in at least one pipe upstream or downstream of the pressure vessel can be controlled, in particular regulated, as a function of the pressure difference between the pressure in the pressure vessel and / or in at least one pipe upstream or downstream of the pressure vessel on the one hand, and the pressure in at least one of the secondary gap channels and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the secondary gap channels, on the other hand. Alternatively or additionally, the pressure control means, in particular, a control device thereof, may be embodied and / or configured such that, by means thereof, the pressure in at least one of the primary gap channels and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the primary gap channels, can be controlled, in particular regulated, as a function of the pressure in at least one of the secondary gap channels and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the secondary gap channels. Furthermore, the pressure control means, in particular, a control device thereof, may be embodied and / or configured such that, by means thereof, the pressure in at least one of the primary gap channels and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the primary gap channels, can be controlled, in particular regulated, as a function of the pressure difference between the pressure in the pressure vessel and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the pressure vessel, on the one hand, and the pressure in at least one of the primary gap channels and / or in at least one, preferably exactly one, pipe connected upstream or downstream of the primary gap channels, on the other hand. For example, the control device for the pressure control means may advantageously be connected to the primary fluid and / or secondary fluid supply means. The control device may further be embodied and / or configured to maintain maximum pressure deviations within the aforementioned ranges. The primary fluid supply means and / or the secondary fluid supply means and / or the pressure fluid supply means may each comprise at least one pipe or be provided by at least one pipe. The primary fluid supply means may also comprise at least one compressor and / or at least one pump and / or at least one valve, which has proven to be particularly advantageous. Similarly, the secondary fluid supply means may comprise at least one compressor and / or at least one pump and / or at least one valve. The pressure fluid supply means may also comprise at least one compressor and / or at least one pump and / or at least one valve. It should be emphasized that, even though the aforementioned supply means may each comprise at least one compressor and / or at least one pump and / or at least one valve, this is by no means a requirement. In the simplest case, these may each consist solely of a supply pipe or an inlet. The pressure fluid supplied to the pressure vessel may, for example, comprise or consist of N and / or liquid water and / or water vapor and / or air. It should be noted that, in a preferred embodiment, the primary fluid is preheated before entering the primary fluid channel(s), for example by means of a heat exchanger provided for preheating the primary fluid. In an advantageous embodiment, the pressure fluid may further be temperature-controlled, in particular heated or cooled. The reactor according to the invention may accordingly comprise a pressure fluid temperature-control device for temperature-controlling the pressure fluid. Provisions may be made for the pressure fluid to be cooled and / or heated before entering the pressure vessel and / or after exiting the pressure vessel. The pressure fluid temperature control device, if present, may be designed and arranged accordingly. A further advantageous embodiment is also characterized in that the pressure fluid is at least partially replaced repeatedly or continuously. Alternatively or additionally, it may be provided that pressure fluid withdrawn from the pressure vessel is returned to the pressure vessel, preferably following cooling and / or heating. The reactor according to the invention may comprise a pressure fluid circuit through which pressure fluid can be discharged from the pressure vessel and returned to the pressure vessel. It may be provided that at least one, preferably all, of the secondary gap channels are supplied with, in particular, boiling methanol or, in particular, boiling water or thermal oil or a molten salt or gas, e.g., compressed air, as a secondary fluid. The plate heat exchanger of the reactor according to the invention, in particular its secondary gap channels, may be embodied accordingly in a further embodiment, for example, made of a suitable material. A suitable heat transfer medium as a secondary fluid, which can be heated by the exothermic reaction on the primary side, may be selected in particular depending on the temperature. Boiling methanol, for example, has proven particularly suitable for a temperature range of 70°C to 130°C. Boiling water is suitable for a temperature range of 130°C to 350°C, which corresponds approximately to a boiling pressure of 2.7 to 165 bar. Thermal oil is particularly suitable for a comparatively high temperature range of 250°C to 450°C, preferably 300°C to 450°C. The same applies to a molten salt, which has proven to be particularly suitable for a temperature range greater than or equal to 400°C, for example in the range of 400°C to 650°C. It is also possible to carry out an endothermic reaction on the secondary side of the plate heat exchanger, which has proven to be particularly advantageous. Accordingly, the reactor according to the invention may be characterized, in a further advantageous embodiment, in that a catalyst material for an endothermic reaction, in particular a catalyst material for a hydrogen release reaction, preferably for ammonia cracking or DME reforming or methane steam reforming or LPG reforming or butane or propane dehydrogenation, is provided in at least one of the secondary gap channels, preferably in all secondary gap channels. In the method according to the invention, it may be provided that a reaction fluid for an endothermic reaction is also supplied to the at least one secondary gap channel as a secondary fluid, and an endothermic reaction, in particular a hydrogen-releasing reaction, preferably ammonia cracking, DME reforming, methane steam reforming, LPG reforming, or butane or propane dehydrogenation, is carried out in the at least one secondary gap channel. For example, a hydrogen-rich compound may be supplied as a secondary fluid to the at least one secondary gap channel, preferably to all secondary gap channels. During a startup phase to initiate the endothermic process, or when electricity costs are low, the plate heat exchanger may preferably be heated electrically to provide heat for the endothermic reaction and to start or maintain that reaction, in particular, a hydrogen release reaction. In a preferred embodiment, the plate heat exchanger of the invention may comprise an electric heating device. For example, one or more plates of the plate heat exchanger may preferably be heated electrically by means of the heating device. If a heating device is present, it can be used to provide heat for an endothermic reaction in the secondary gap channels during a startup phase or when electricity costs are low. It is also possible, during a startup phase, to supply a heated fluid or gas to at least one primary gap channel, preferably all primary gap channels, in order to preheat the catalyst and initiate the endothermic reaction. This form of heating may be performed as an alternative to or in addition to an electric heating of the plate heat exchanger, such as of its plates. Alternatively or in addition, the secondary side can be used to heat the reactor at startup. For example, if thermal oil is supplied as the secondary fluid, the thermal oil or the thermal oil circuit can be heated. The reactor according to the invention may, for design purposes, include heating means for heating the secondary fluid. In this case, for example, electric heating plates in the reactor may be dispensed with. Another advantageous embodiment of the invention is characterized in that the secondary fluid vaporizes and / or becomes superheated as a result of absorbing the heat released during the exothermic reaction in the at least one primary gap channel. It is also possible to use the heated secondary fluid to generate steam, in particular superheated steam. The generated and / or superheated steam can then, for example, be supplied to at least one solid-oxide electrolyzer cell to produce hydrogen, preferably, wherein the produced hydrogen is subsequently used to produce ammonia (NH3). Such a configuration has proven to be particularly energy efficient. The reactor according to the invention may accordingly comprise at least one solid-oxide electrolyzer cell. Furthermore, it may be provided that at least one of the secondary gap channels is subdivided into several sub-secondary gap channels that preferably are fluidically connected in parallel with one another. Such a subdivision, so to speak, into several “sub-secondary gap channels” may also be provided for all secondary gap channels. Alternatively or additionally, at least one of the secondary gap channels, or even all of the secondary gap channels, may have a meandering course. If there is a subdivision into several “sub-secondary gap channels,” these may also be meandering. Furthermore, it has proven advantageous for the primary gap channels to be connected to one another via a primary distribution channel and a primary collector channel. Alternatively or additionally, it may be provided in a similar manner that the secondary gap channels are connected to one another via a secondary distribution channel and a secondary collector channel. For example, each plate may have four holes, specifically round holes, wherein the holes in all plates are located at identical positions and the holes of all plates are aligned, and aligned holes form a preferably cylindrical primary / secondary distribution or collection channel extending across the plates and the gap channels defined between them. If four holes are provided in each plate, a primary distribution channel and a primary collection channel, as well as a secondary distribution channel and a secondary collection channel, are formed or defined. The holes are preferably located in the peripheral region of the plates. If the plates are quadrilateral, in particular, at least substantially rectangular or square, one of the holes may be located, for example, in or near each corner of each plate. Another advantageous embodiment of the invention is characterized in that the primary gap channels of the plate heat exchanger are connected to a preferably central primary inlet pipe, and a preferably central primary outlet pipe. Similarly, the secondary gap channels may be connected to a preferably central secondary inlet line and a preferably central secondary outlet line. The primary gap channels may, for example, be connected to a primary inlet pipe via a primary distribution channel and to a primary outlet pipe via a primary collector channel. The secondary gap channels may be connected in a similar manner via a secondary distribution channel to a secondary inlet pipe and via a secondary collector channel to a secondary outlet pipe. Usually, the plates of the plate heat exchanger will have the same shape, for example, all will be at least approximately rectangular, and / or will have the same external dimensions. It is also possible that several, or even all, of the plates in the plate heat exchanger are of identical construction. The plates are preferably made of metal or incorporate metal. Alternatively or additionally, the plates have a textured surface or profiling on at least one side. Preferably, the at least one side that has a textured surface or profiling is a side that defines or delimits a gap channel. In an advantageous further embodiment, the plate heat exchanger may be provided on the outside with an insulating layer made of a thermally insulating material. In this way, excessive heating of the pressure vessel surrounding the plate heat exchanger during operation can be prevented. The plate heat exchanger may further comprise a housing. In this case, the housing, in particular, may include an insulating layer made of a thermally insulating material. The invention also relates to the use of a reactor according to the invention for a catalytic oxidation reaction, in particular for a catalytic oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, and / or for a hydrogen release reaction, in particular for NH3 cracking or methanol reforming or DME reforming or methane steam reforming or LPG reforming or butane or propane dehydrogenation, and / or for heating water to produce saturated steam or superheated steam. The combination of a catalytic oxidation reaction (exothermic), in particular a catalytic oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, on the primary side, and the heating of water to saturated steam or superheated steam on the secondary side (using the heat released on the primary side) has proven to be particularly suitable. Another particularly advantageous combination consists of a catalytic oxidation reaction (exothermic), in particular a catalytic oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, on the primary side, and methanol reforming (endothermic) on the secondary side. With regard to the embodiments of the invention, reference is also made to the subclaims and to the following description with reference to the accompanying drawing. The drawing shows: Figure 1    an exemplary embodiment of a reactor according to the inven tion in a purely schematic cross-sectional view, Figure 2    a perspective exterior view of the reactor shown in Figure 1, and Figure 3    a further purely schematic cross-sectional view of the reactor shown in Figure 1. Identical reference numerals are used in the figures for identical or similar components and elements. Figure 1 shows, in a purely schematic cross-sectional view, a first embodiment of a reactor 1 according to the invention. Figure 2 shows reactor 1 in a perspective exterior view, and Figure 3 shows another schematic crosssectional view. The reactor 1 is designed to carry out exothermic reactions. The reactor 1 comprises a plate heat exchanger 2 with a plurality of adjacent plates 3, which are oriented, in particular, at least substantially parallel to one another. In Figure 1, only a few of the plates 3 are shown as examples and are designated by the reference numeral 3. In the embodiment shown here, the plates 3, which are made of metal, all have a rectangular outer contour and the same dimensions; in other words, they are all the same size. Gap channels 4 and 5 are defined between the plates 3; specifically, there is one gap channel 4 between each pair of adjacent plates 3, 5. The gap channels 4, 5 are divided into two groups, namely several primary gap channels 4 that are fluidically connected to one another, in particular fluidically connected in parallel,, and several secondary gap channels 5 that are flu-idically connected to one another, in particular fluidically connected in parallel. The gap channels 4 of one group, the primary gap channels 4, alternate with the gap channels 5 of the other group, the secondary gap channels 5. Accordingly, each primary gap channel 4 is located between two secondary gap channels 5 or, in the case of the primary gap channel 4 on the far left in the figure, adjacent to a secondary gap channel 5. Similarly, a secondary gap channel 5 is located between two primary gap channels 4 or, in the case of the secondary gap channel 5 on the far right edge of the figure, adjacent to a primary gap channel 4. Each of the primary gap channels 4 contains a catalyst material 6 for an exothermic reaction. In the highly simplified, purely schematic Figure 1, the catalyst material 6 is shown only as an example in some of the primary gap channels 4. In Figure 1, a granular catalyst material 6 is schematically illustrated by way of example, and this is shown only over a section of the respective primary gap channel 4. It is understood that the primary gap channels 4 may be filled with a catalyst material 6, for example, a granular catalyst material, over their entire length. Alternatively or additionally, the plates 3 may be coated with catalyst material 6 or with a coating material comprising catalyst material 6. One or more insert plates may also be positioned in the primary gap channels 4, which consist of the catalyst material or are coated with the catalyst material, for example by a washcoat, which can simplify manufacturing. It is also possible for the catalyst material to be present in the form of catalytically active structures. By way of example, catalytically active networks may be provided in the primary gap channels and / or the secondary gap channels. It should be noted that the internal structure of the plate heat exchanger 2, including the plates 3, primary and secondary gap channels 4, 5, and the catalyst material 6, is shown only in Figure 1 but is not depicted again in Figure 2. In the present case, the catalyst material 6 is intended for a catalytic oxidation reaction of hydrogen, in particular a catalytic combustion of hydrogen with oxygen. The oxidation reaction is as follows: H2(g) + ½ O2(g) ^ H2O(g) A H° = -242 kJ morl In the illustrated embodiment, the primary gap channels 4 contain a catalyst material 6 comprising or consisting of platinum, specifically, platinum deposited on a metal oxide support. All primary gap channels 4 contain the same catalyst material 6. The reactor 1 further comprises primary fluid supply means 7 for supplying a primary fluid to the primary gap channels 4. In the example shown, a combustion mixture comprising a gaseous fuel and a gaseous oxidizing agent is supplied as the primary fluid. Specifically, a primary fluid comprising a mixture of hydrogen and oxygen is supplied. The primary fluid is outside the explosive range. The oxygen concentration of the primary fluid is below the limiting oxygen concentration. The primary fluid can also be referred to as a reaction fluid or reaction gas. The primary fluid supply means 7 comprise at least one blower / compressor and / or at least one valve, which are not shown separately in the purely schematic Figure 1. As can be seen in Figure 1, the primary gap channels 4 are all fluidically connected on the inlet side to a central primary distribution channel 8, which, in the illustrated embodiment, is part of the primary fluid supply means 7. During operation, the primary fluid enters the primary distribution channel 8 via the central primary inlet pipe 9 of the primary fluid supply means 7, indicated by an arrow in Figure 1. The primary fluid supplied can be distributed to all primary gap channels 4 via the primary distribution channel 8. The reactor 1 also includes secondary fluid supply means 10 for supplying a secondary fluid to the secondary gap channels 5. The secondary fluid supply means 10 comprise at least one pump and / or at least one valve, which are not shown separately in the purely schematic Figure 1. The secondary gap channels 5 are, similar to the primary gap channels 4, all fluidically connected on the inlet side to a central secondary distribution channel 11, which, in the illustrated embodiment, is part of the secondary fluid supply means 10. During operation, the secondary fluid enters the secondary distribution channel 11 via the upstream, central secondary inlet pipe 12 of the secondary fluid supply means 10. On the outlet side of the primary gap channels 4, a primary collector channel 13 is provided, in which fluid exiting all primary gap channels 4 can be collected and discharged from the plate heat exchanger 2 via a central primary outlet pipe 14. On the outlet side of the secondary gap channels 5, a secondary collector channel 15 is provided in a similar manner, in which fluid exiting all secondary gap channels 5 is collected and can exit the plate heat exchanger 2 via a central secondary outlet pipe 16. The primary gap channels 4 and the secondary gap channels 5 are not flu-idically connected to one another. In the embodiment shown here, the plate heat exchanger 2 has a rectangular housing 17, through the wall of which the inlet and outlet pipes 9, 12, 14, 16 for the primary and secondary fluids extend. It should be noted that, in the schematic Figure 1, the two distribution and collection channels 8, 11, 13, 15 are shown above and below the plates 3, respectively, for the sake of clarity. However, these channels may also extend through the plates 3 and may, in particular, be defined by recesses provided in the plates 3. For example, four holes—in particular round holes (not shown in the figure)—may be provided in each plate 3, with the holes located at identical positions in all plates 3 and the holes of all plates 3 being aligned, whereby aligned holes form a primary or secondary distribution or collection channel 8, 11, 13, 15—in particular a cylindrical channel— extending transversely through the plates 3 and the gap channels 4, 5 defined between them. This is known from conventional or conventionally used plate heat exchangers. The connection of the respective distribution or collection channels 8, 11, 13, 15 to the associated gap channels, or their separation therefrom, can then be achieved by means of gaskets (not shown), as is well known from conventional plate heat exchangers. The holes are preferably located in the edge region of the plates 3. If the plates 3 are rectangular, as in the illustrated embodiment, one of the holes may be located in or near each corner. In the embodiment shown here, which involves an exothermic reaction on the primary side, the secondary fluid used is, for example, a cooling fluid such as boiling methanol, boiling water, thermal oil, or a molten salt. The reactor 1 also comprises a pressure vessel 18 that surrounds the plate heat exchanger 2. As can be seen in the figures, the pressure vessel 18 has a hollow cylindrical jacket section and rounded, outwardly curved end faces. The cube- or rectangular-shaped plate heat exchanger 2 is arranged inside the pressure vessel 18. The pressure vessel 18 comprises an outer shell made of cost-effective steel, the inner surface of which is provided with an insulating layer of a thermally insulating material. The thermal insulation ensures or helps ensure that the outer shell reaches a maximum temperature of 200°C, preferably a maximum of 70°C, during operation, which enables the use of cost-effective steels. It should be noted that, alternatively or in addition, the plate heat exchanger 2, for example, its housing 17, may be provided with an insulating layer made of a thermally insulating material. The pressure vessel 18 is constructed in two parts: a first part 18a and a second part 18b. The two parts 18a and 18b are detachably connected to one another via integrally formed flanges 18c and screws not shown in the figures. The plate heat exchanger 2 is held in the pressure vessel 18 by a bracket 18d, which is preferably attached to the flanges 18c, at a distance from the pressure vessel wall (see Figure 3). Additionally, depending on the length of the plate heat exchanger 2, further brackets may be provided, in particular in the pressure vessel section 18a. It should be noted that the two-part design of the pressure vessel 18 is not visible in the purely schematic, simplified Figure 1. Pressure fluid supply means 19 are also provided, which are configured to supply a pressure fluid to the interior 20 of the pressure vessel 18 and to generate an elevated pressure of at least 2 bar, in particular at least 5 bar, preferably at least 10 bar, and most preferably at least 20 bar, within the interior 20 of the pressure vessel 18. The pressure fluid supply means 19 comprise at least one compressor and / or at least one valve, which are not shown separately in the schematic Figure 1. The pressure vessel 18 and the pressure fluid supply means 19 ensure that, during operation of the plate heat exchanger 2, when the exothermic reaction takes place on the primary side and, if applicable, an endothermic reaction on the secondary side, there is no pressure difference, or only a small one, particularly between the secondary gap channels 5 and the interior 20 of the pressure vessel 18, and the plate heat exchanger 2 can therefore be designed with simpler seals. It should be noted that in the schematic, highly simplified Figure 1, the seals, which, in particular, prevent the escape of primary and secondary fluids into the pressure vessel 18 and the entry of pressure fluid into the primary and secondary gap channels 4, 5, are not shown. A pressure fluid, such as nitrogen, water, steam, or air, can be supplied to the pressure vessel 18 via the pressure fluid supply means 19. Temperature control of the pressure fluid may be provided. The reactor 1 shown in Figure 1 comprises a pressure fluid circuit 21 with a pressure fluid temperature control device, which comprises a heat exchanger 22 or is provided thereby. Pressurized gas can be withdrawn from the pressure vessel 18 via the pressure fluid circuit 21, cooled or heated by the pressure fluid temperature control device, in particular by the heat exchanger 22, and returned to the pressure vessel 18. The circuit 21 also includes a compres-sor / pump 23. Additional cooling can be achieved using a recirculated, cooled pressure fluid. The pressure vessel 18 may also be equipped with a leak sensor (not shown). Pressure control means are provided, which are designed and / or configured such that they allow the pressure difference, which exists during operation of the reactor 1 between the pressure in the pressure vessel 18 and the pressure in the secondary gap channels 5, to be controlled, preferably regulated. Reactor 1, in particular the pressure control means, specifically comprises a control device 24 by means of which the pressure in the interior 20 of the pressure vessel 18 can be controlled, preferably regulated. The control device 24 can also be used to control, preferably regulate, the pressure in the secondary gap channels 5. For this purpose, the control device 24 is suitably connected to the secondary fluid supply means 10 and the pressure fluid supply means 19, such as compressors thereof. Pressure measuring devices, such as pressure sensors, may be provided for measuring the pressure in the pressure vessel 18 and / or the pressure in at least one secondary gap channel 5. Alternatively or additionally, a secondary differential pressure measuring device may be provided to measure the pressure difference between the pressure in the pressure vessel 18 and the pressure in at least one of the secondary gap channels 5. Alternatively or additionally, a pressure measuring device may be provided to measure the pressure in at least one primary gap channel 4. The pressure measuring devices and / or the secondary differential pressure measuring device may be part of the pressure control means. The control device 24 may be connected to the pressure measuring device and / or the differential pressure measuring device in order to perform control or regulation based on the measured pressure values. It should be noted that, as an alternative or in addition to measuring pressure in the pressure vessel 18 or at least one secondary gap channel 5, the pressure may also be measured in the supply pipe, specifically, in at least one pipe connected upstream of the pressure vessel 18 in the fluid system or in at least one pipe connected upstream of one or more, or possibly all, secondary gap channels 5. By way of example, at least one pressure measuring device, e.g., at least one pressure sensor, is provided for measuring the pressure in the secondary inlet pipe 12 and / or the secondary distributor channel 11, for instance in at least one of its multiple branches. Even in the case of differential pressure measurement, the measurement can be based on the supply pipe, specifically, at least one pipe upstream of the pressure vessel 18 or at least one secondary gap channel 5. With regard to the primary gap channels 4, it may alternatively or additionally be the case that at least one pressure measuring device, e.g., at least one pressure sensor, is provided for measuring the pressure in the primary inlet pipe 8 and / or the primary distribution channel 8, for example in at least one of the multiple branches thereof. Even in the case of differential pressure measurement, the measurement can be performed on the supply pipe—specifically, at least one pipe upstream of the pressure vessel 18 or at least one primary gap channel 4 or secondary gap channel 5. Alternatively or in addition to performing the pressure measurement in a supply pipe, it may also be performed in at least one downstream pipe. By way of example, at least one pressure measuring device, e.g., at least one pressure sensor, is provided for measuring the pressure in the secondary collector channel 15, for example in at least one of its multiple branches. In the case of differential pressure measurement as well, the discharge, specifically, at least one pipe downstream of the pressure vessel 18 or at least one secondary gap channel 5, can be shut off. The same applies to the primary gap channels 4. Thus, at least one pressure measuring device, e.g., at least one pressure sensor, may be provided for measuring the pressure in the primary outlet pipe 14 and / or the primary collector channel 13, for example in at least one of its multiple branches. In the case of differential pressure measurement as well, the pressure can be diverted to the discharge pipe, specifically, at least one pipe connected downstream of at least one primary gap channel 4 or secondary gap channel 5. It goes without saying that other combinations of pressure measuring devices are also possible and that the foregoing is provided by way of example. The pressure vessel 18 has a pressure fluid outlet pipe 25 in which an outlet valve 26 is arranged. Pressure fluid can exit the pressure vessel 18 via the pressure fluid outlet pipe 25. A safety valve may additionally be provided that opens when the pressure becomes too high (not shown in the figure). Pressure fluid can then flow through such safety valve to, for example, a flare or a safe location. There also is a vent valve 27 for the plate heat exchanger 2. During operation of the reactor 1, the primary fluid is supplied to the primary gap channels 4—in other words, the primary side of the plate heat exchanger 2, and water, for example, is supplied as the secondary fluid to the secondary gap channels 5, i.e., the secondary side. At the same time, a pressure fluid, in this case, nitrogen or air, is supplied to the pressure vessel. It should be noted that the primary fluid and / or secondary fluid can be preheated before entering the primary gap channels 4 and secondary gap channels 5, respectively. Reactor 1 may include a heat exchanger for preheating the primary fluid and / or the secondary fluid (not shown). In the primary gap channels 4, hydrogen is oxidized according to the above equation, releasing heat. Cooling takes place via the secondary side of the plate heat exchanger 2, using water flowing through the secondary gap channels 5. Specifically, the water in the secondary gap channels 5 is heated to 165 bar and 350°C, resulting in saturated steam or superheated steam, due to the exothermic, catalytic oxidation reaction of hydrogen on the primary side. In the process, water enters the plate heat exchanger 2, specifically, the secondary gap channels 5, in liquid form at 340°C. Saturated steam or superheated steam at 350°C or more than 350°C exits into the secondary outlet pipe 16. The catalytic oxidation of hydrogen takes place in the primary gap channels 4, preferably under the conditions described in DE 10 2023 200 245 B3. In the embodiment shown in Figure 1, additional cooling can be provided by the cooled pressure fluid The pressure in the pressure vessel 18 is adjusted to the pressure in the secondary gap channels 5 by means of the control device 24. Specifically, reactor 1 is operated such that the pressure in pressure vessel 18, by means of control device 24, is maintained at a level that is at most 20%, in particular at most 10%, preferably at most 5%, and most preferably at most 1% above or below the pressure in the secondary gap channels 5. In the embodiment described here, reactor 1 is operated such that the pressure in the pressure vessel 18 is at most 5 bar, in particular at most 1 bar, preferably at most 100 mbar, above or below the pressure in the secondary gap channels 5. The control device 24 is embodied and / or configured accordingly. The primary side, specifically, the primary gap channels 4, may be at the same or a similar pressure, or even at a (significantly) different pressure, such as atmospheric pressure. If the same or a similar pressure is desired, the reactor 1 can, for example, be operated such that the pressure in the primary gap channels 4 is at most 20%, in particular at most 10%, preferably at most 5%, and most preferably at most 1% above or below the pressure in the secondary gap channels 5. Specifically, reactor 1 can be operated such that the pressure in the primary gap channels 4 is at most 5 bar, in particular at most 1 bar, preferably at most 100 mbar, above or below the pressure in the secondary gap channels 5. The control device 24 is embodied and / or configured accordingly. In particular, if a plate heat exchanger 2 with a more complex seal and stabilizing webs is used, operation with more significantly differing pressures is also possible. The leak sensor of the pressure vessel 18 monitors for the absence of gas. In particular, the leak sensor detects a leak between the secondary gap channels 5 and the pressure vessel 18 when the pressure in the secondary gap channel 5 is slightly higher than that in the pressure vessel 18. Primary fluid exiting the primary gap channels 4 on the outlet side after the reaction is collected in the primary collector channel 13 and can be discharged via the primary outlet pipe 14 from the plate heat exchanger 2 and the pressure vessel 18 and supplied to a desired application, e.g., heat recovery as described in DE 10 2023 200 245 B3. Heated secondary fluid, in this case, in the form of saturated steam or superheated steam, emerges from the secondary gap channels 5 on the outlet side. The saturated steam or superheated steam can also be directed to a desired application. It is also possible to carry out an endothermic reaction, e.g., a hydrogen release reaction, on the secondary side of the plate heat exchanger 2 and to use this reaction to absorb and remove the heat released during the exothermic reaction, in this case, the catalytic oxidation of hydrogen, in the primary gap channels 4. If this is the case, a catalyst material for an endothermic reaction, such as a hydrogen release reaction, is advantageously provided in the secondary gap channels 5 (not shown in Figure 1). In other words, not only the primary gap channels 4 but also the secondary gap channels 5 can be filled with a catalyst material. In this case, a reaction fluid for the endothermic reaction is supplied to the secondary gap channels 5 as the secondary fluid. In other words, a reaction fluid for an endothermic reaction is used as the secondary fluid for cooling. For a hydrogen release reaction, for example, a hydrogen-rich compound would be supplied as the secondary fluid, and hydrogen would be released while absorbing heat from the reaction side. Methanol reforming is an example of a hydrogen-releasing reaction carried out on the secondary side. In this case, a methanol reforming catalyst material 6, which comprises or consists of Cu or Pd / Zn, is suitably arranged in the secondary gap channels 5. It has proven particularly advantageous to carry out methanol reforming in the secondary gap channels 5 and a catalytic oxidation reaction of a portion of the product stream in the primary gap channels 4. The product stream may consist predominantly of hydrogen (and CO2) and may contain smaller amounts of methanol and CO. In particular, the retentate from a separation process of the product stream, e.g., from membrane separation or pressure-swing adsorption, can be used as the primary fluid. Together with an oxidizing agent, such as atmospheric oxygen, the oxidizable species (hydrogen, methanol, CO) can be oxidized on the primary side to CO2, thereby providing the heat required for the endothermic methanol reforming on the secondary side. In the pressure vessel 18, a pressure is suitably set to 20 bar (similar to the methanol reforming pressure that prevails in the secondary gap channels 5 during operation) or deviates by no more than the aforementioned pressure or percentage values from 20 bar. This is done in exactly the same way as described above using the example of heating water to saturated steam (secondary side) by means of the catalytic oxidation reaction (primary side). The pressure in the primary gap channels 4 may also correspond at least approximately to this pressure or deviate more significantly from it, for example, corresponding to atmospheric pressure. Other endothermic reactions whose implementation on the secondary side has also proven to be particularly suitable as an alternative to methanol reforming include -     NH3 cracking -     DME reforming -     Methane steam reforming -     LPG reforming -     Butane / propane dehydrogenation In all of these reactions, a retentate stream from product preparation can be used to provide heat through oxidation (via the primary side). The catalytic oxidation of hydrogen in the primary gap channels 4 can take place in all cases under the conditions described in DE 10 2023 200 245 B3. If an endothermic reaction is carried out on the secondary side, the plate heat exchanger 2 may be designed to be (electrically) heatable in order to provide heat for the endothermic reaction during a startup phase and / or when electricity costs are low. It is also possible to heat the secondary fluid, particularly by external means. If an endothermic reaction, such as an endothermic hydrogen release reaction, is utilized on the secondary side, a hydrogen-rich compound can be supplied to the secondary gap channels 5 as a secondary fluid. In the secondary gap channels 5, which, in this case, are equipped with a suitable catalyst material for the endothermic reaction, hydrogen is released, and hydrogen and a hydrogen-poor compound exit the secondary gap channels 5 on the outlet side and enter the secondary collector channel 15. In the case of a hydrogen release reaction, it has proven particularly efficient to recirculate the hydrogen obtained on the secondary side back to the primary side. The reactor 1 may be designed accordingly, in particular to include suitable pipes for such recirculation. During a startup phase to initiate the process, it is then appropriate to first electrically heat the plate heat exchanger 2 in order to provide heat for the hydrogen release reaction and to initiate it. Heated nitrogen may also be fed into the primary gap channels 4 during the startup phase in order to preheat the catalyst for the endothermic reaction and initiate the reaction. Until hydrogen becomes available via the hydrogen release reaction, it is preferably supplied to the primary side initially. For this purpose, another source may be used temporarily, e.g., an electrolyzer or a separate hydrogen release reaction unit. List of References 1     Reactor 2     Plate heat exchanger 3     Plate 4     Primary gap channel 5    Secondary gap channel 6     Catalyst material 7     Primary fluid supply means 8     Primary distribution channel 9     Primary inlet pipe 10   Secondary fluid supply means 11    Secondary distribution channel 12    Secondary inlet pipe 13    Primary collector channel 14    Primary outlet pipe 15    Secondary collector channel 16   Secondary outlet pipe 17   Housing 18    Pressure vessel 18a  Part 18b  Part 18c  Flange 18d  Mounting Bracket 19    Pressure fluid supply means 20    Interior of the pressure vessel 21    Pressure fluid circuit 22   Heat exchanger 23   Compressor 24    Control unit 25    Pressure outlet pipe 26    Discharge valve 27    Vent valve

Claims

1. Reactor (1) for carrying out exothermic reactions, comprising-     a plate heat exchanger (2) having a plurality of adjacent plates (3),in particular plates oriented at least substantially parallel to one another, between which gap channels (4, 5) are defined, wherein the gap channels (4, 5) are subdivided into several primary gap channels (4) that are fluidically connected, in particular fluidically connected in parallel, and several secondary gap channels (5) that are fluidically connected, in particular fluidically connected in parallel, wherein in at least one of the primary gap channels (4), preferably in all primary gap channels (4), a catalyst material (6) for an exothermic reaction, in particular for a catalytic oxidation reaction, preferably for a catalytic oxidation reaction of hydrogen, and most preferably for a catalytic combustion of hydrogen with oxygen, is provided, and wherein primary fluid supply means (7) are provided for supplying a primary fluid to the primary gap channels (4) and secondary fluid supply means (10) are provided for supplying a secondary fluid to the secondary gap channels (5),-     a pressure vessel (18) surrounding the plate heat exchanger (2),-     pressure fluid supply means (19) configured to supply a pressurefluid to the pressure vessel (18) and, in particular, to generate an elevated pressure of at least 2 bar, in particular of at least 5 bar, preferably of at least 10 bar, and most preferably of at least 20 bar, within the pressure vessel (18).

2. Reactor (1) according to claim 1, characterized in that pressurecontrol means are provided, and the pressure control means are embodied and / or configured such that the pressure difference that exists duringoperation of the reactor (1) between the pressure in the pressure vessel (18) and the pressure in at least one of the secondary gap channels (5), preferably in all secondary gap channels (5), can be controlled, preferably regulated, with the pressure control means, in particular, wherein the pressure control means are embodied and / or configured to maintain, during operation of the reactor (1), the pressure in the pressure vessel (18) at a level that is at most 20%, in particular at most 10%, preferably at most 5%, and most preferably at most 1% above or below the pressure in at least one secondary gap channel (5), preferably in all secondary gap channels (5),and / or to maintain, during operation of the reactor (1), the pressure in the pressure vessel (18) at a level that is at most 5 bar, in particular at most 1 bar, preferably at most 100 mbar, above or below the pressure in at least one of the secondary gap channels (5), preferably in all secondary gap channels (5).

3. Reactor (1) according to claim 2, characterized in that the pressurecontrol means comprise a pressure measuring device for measuring the pressure in the pressure vessel (18) and / or the pressure in at least one pipe upstream of the pressure vessel (18) and / or in at least one pipe downstream of the pressure vessel (18), and a secondary pressure measuring device for measuring the pressure in at least one of the secondary gap channels (5) and / or the pressure in at least one pipe upstream of the secondary gap channels (4) and / or in at least one pipe downstream of the secondary gap channels (4),and / or in that the pressure control means comprise a secondary differential pressure measuring device for measuring the pressure difference between the pressure in the pressure vessel (18) and / or the pressure in at least one pipe upstream of the pressure vessel (18) and / or in at least one pipe downstream of the pressure vessel (18) on the one hand, and the pressure in at least one of the secondary gap channels (5) and / or the pressure in at leastone pipe upstream of the secondary gap channels (4) and / or in at least one pipe downstream of the secondary gap channels (4), on the other hand.

4. Reactor (1) according to any one of the preceding claims, characterized in that in at least one of the secondary gap channels (5), preferably in all secondary gap channels (5), a catalyst material for an endothermic reaction, in particular a catalyst material for a hydrogen release reaction, specifically for NH3 cracking or methanol dehydrogenation or methanol reforming or DME reforming or methane steam reforming or LPG reforming or butane or propane dehydrogenation, is provided.

5. Reactor (1) according to any one of the preceding claims, characterized in that the plate heat exchanger (2) comprises a preferably electric heating device, in particular, wherein one or more plates (3) of the plate heat exchanger (2) can preferably be heated electrically by means of the heating device, and / or in that a heating device arranged outside the pressure vessel (18) is provided, by means of which the secondary medium, which can be supplied to the secondary gap channels (5) by means of the secondary fluid supply means, can be heated.

6. Reactor (1) according to any one of the preceding claims, characterized in that the catalyst material provided in the primary gap channel(s) (4) comprises at least one noble metal, in particular platinum and / or palladium, specifically platinum provided on an aluminum oxide support.

7. Reactor (1) according to any one of the preceding claims, characterized in that the primary gap channels (4) and / or the secondary gap channels (5) are provided with stabilizing elements, in particular stabilizing ribs.

8. Reactor (1) according to any one of the preceding claims, characterized in that the pressure vessel (18) is provided on the inside with an insulating layer made of a thermally insulating material, and / or that the pressure vessel (18) comprises steel, in particular a steel outer shell, and / or in that a leak sensor is provided for monitoring the plate heat exchanger (2), wherein the leak sensor is preferably arranged inside the pressure vessel (18).

9. Reactor (1) according to any one of the preceding claims, characterized in that the plate heat exchanger (2) is provided on the outside with an insulating layer made of a thermally insulating material, and / or in that the plates (3) of the plate heat exchanger (2) are at least substantially rectangular in shape and / or have a textured surface on at least one side.

10. Reactor (1) according to any one of the preceding claims, characterized in that the primary gap channels (4) and the secondary gap channels (5) are not fluidically connected to one another, and / or that the primary gap channels (4) and the secondary gap channels (5) are arranged alternately.

11. Reactor (1) according to any one of the preceding claims, characterized in that a pressure fluid circuit (21) is provided, via which pressure fluid can be discharged from the pressure vessel (18) and returned to the pressure vessel (18), and / or that a pressure fluid temperature control device for cooling and / or heating the pressure fluid is provided, preferably, wherein the pressure fluid temperature control device is embodied and arranged such that pressure fluid can be cooled and / or heated by means thereof before entering the pressure vessel (18) and / or after exiting the pressure vessel (18).

12. Use of a reactor (1) according to any one of the preceding claims for a catalytic oxidation reaction, in particular for a catalytic oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, and / or for a hydrogen release reaction, in particular for NH3 cracking or methanol reforming or DME reforming or methane steam reforming or LPG reforming or butane or propane dehydrogenation, and / or for heating water to produce saturated steam or superheated steam.

13. Method for operating a reactor (1) according to any one of claims 1 to 11, comprising the steps- a primary fluid is supplied to at least one primary gap channel (4), preferably all primary gap channels (4), and in the at least one primary gap channel (4), preferably in all primary gap channels (4), an exothermic reaction, in particular an oxidation reaction of hydrogen, preferably a catalytic combustion of hydrogen with oxygen, is carried out,- a secondary fluid is supplied to at least one secondary gap channel (5), preferably to all secondary gap channels (5),- a pressure fluid, in particular a pressure gas, is supplied to the pressure vessel (18), preferably, wherein the pressure fluid comprises N2 and / or liquid water and / or water vapor and / or air, or is provided thereby.

14. Method according to claim 13, characterized in that the reactor (1) is operated such that the pressure in the pressure vessel (18) is at most 20%, in particular at most 10%, preferably at most 5%, and most preferably at most 1% above or below the pressure in at least one of the secondary gap channels (5), preferably in all secondary gap channels (5), and / or that the reactor (1) is operated such that the pressure in the pressure vessel (18) is at most 5 bar, in particular at most 1 bar, preferably atmost 100 mbar, above or below the pressure in at least one of the secondary gap channels (5), preferably in all secondary gap channels (5).

15. Method according to any one of claims 13 or 14, characterized in that the pressure fluid is at least partially exchanged repeatedly or continuously, and / or that pressure fluid withdrawn from the pressure vessel (18) is returned to the pressure vessel (18), preferably after cooling and / or heating.

16. Method according to any one of claims 13 to 15, characterized in that a primary fluid comprising or consisting of a mixture of hydrogen and oxygen is supplied to the at least one primary gap channel (4), preferably wherein a primary fluid is supplied that is outside the explosive range, and / or in that a primary fluid comprising a retentate, in particular a reten-tate originating from product processing, is supplied to the at least one primary gap channel (4).

17. Method according to any one of claims 13 to 16, characterized in that preferably boiling methanol or preferably boiling water, or a thermal oil, or a molten salt, or a gas, in particular compressed air, is supplied to the at least one secondary gap channel (5) as a secondary fluid.

18. Method according to any one of claims 13 to 17, characterized in that a reaction fluid for an endothermic reaction is supplied to the at least one secondary gap channel (5) as a secondary fluid, and an endothermic reaction, in particular a hydrogen release reaction, preferably NH3 cracking or DME reforming or methane steam reforming or methanol reforming or LPG reforming or butane or propane dehydrogenation, is carried out in the at least one secondary gap channel (5).

19. Method according to claim 18, characterized in that, during a startup phase, the plate heat exchanger (2) is heated to provide heat for the endothermic reaction.5   20. Method according to claim 18 or 19, characterized in that methanolreforming is carried out in the at least one secondary gap channel (5) and that a catalytic oxidation reaction of a portion of the product stream is carried out in the at least one primary gap channel (4).10   21. Method according to any one of claims 13 to 20, characterized inthat the secondary fluid is vaporized and / or superheated as a result of absorbing the heat released during the exothermic reaction in the at least one primary gap channel (4), or that heated secondary fluid is used to generate and / or superheat steam.1522. Method according to any one of claims 13 to 21, characterized in that saturated steam or superheated steam is generated in at least one of the secondary gap channels (5), preferably in all secondary gap channels (5).

Images