Electrolysis system, electrolysis equipment, and method for generating synthesis gas

Abstract

The present invention relates to a fuel cell system (10), a fuel cell facility (30) having the fuel cell system (10) and a synthesis system (20), and a method (1000) for generating synthesis gas by the fuel cell system (10).

Description

Technical Field

[0001] The present invention relates to Electrolysis systems,[[]] Electrolysis facilities, and Electrolysis a method for generating synthesis gas by a system.[[]]

[0002] One possibility to reduce the dependence on the production of fossil raw materials and to reduce CO2 emissions is to replace crude oil with synthetic hydrocarbons made from carbon dioxide (CO2) and water (H2O). In that case, synthesis gas containing hydrogen (H2) and carbon monoxide (CO) can be generated by high-temperature steam electrolysis (abbreviated as SOE for "Solid Oxide Electrolysis" in English) under the supply of an electric current. Synthetic hydrocarbons can be obtained from the synthesis gas in a subsequent synthesis process.[[]]

[0003] The object of the present invention is to easily increase the efficiency of the above-mentioned high-temperature steam electrolysis at low cost.[[]]

[0004] The above object is solved by a Electrolysis system having the features of claim 1, a Electrolysis facility having the features of claim 16, and a method having the features of claim 17. Other features and details of the present invention will become apparent from the dependent claims, the following description, and the drawings. In that case, the features and details described in connection with the Electrolysis system according to the present invention are, of course, also applicable in connection with the Electrolysis facility according to the present invention and the method according to the present invention, and vice versa, whereby the individual aspects of the present invention are always mutually referable or can be referred to with respect to the disclosure of each other.[[]]

[0005] According to the present invention, a Electrolysis system is contemplated, particularly as an electrolysis system, preferably designed to perform co-electrolysis.[[]] Electrolysis The system has a cathode part including a cathode supply part and a cathode discharge part, and an anode part including an anode supply part and an anode discharge part.[[]] Electrolyzer stack Furthermore,[[]] ElectrolysisThe system has an anode gas connection for supplying anode gas to the anode part, which is fluid-technically connected to the anode supply part by means of an anode supply connection (Anodenzufuehrverbindung). Furthermore, Electrolysis the system has an anode discharge connection for discharging the anode exhaust gas generated thereby, which is fluid-technically connected to the anode discharge part by means of an anode discharge connection (Anodenabfuehrverbindung). Electrolyzer stack Furthermore, Electrolysis the system has a cathode gas connection for supplying cathode gas to the cathode part, which is fluid-technically connected to the cathode supply part by means of a cathode supply connection (Kathodenzufuehrverbindung). Furthermore, Electrolysis the system has a cathode discharge connection for discharging the synthesis gas generated thereby, which is fluid-technically connected to the cathode discharge part by means of a cathode discharge connection (Kathodenabfuehrverbindung). Electrolyzer stack Furthermore, Electrolysis the system Also, an electrolyzer stack in a synthesis process for producing synthetic hydrocarbons generates is synthesis gas from and has a residual gas supply connection for providing the residual gas separated therefrom. having Furthermore, Electrolysis the system is fluid-technically connected to the residual gas supply connection by means of a residual gas supply connection and further has two catalysts for catalytic combustion of the residual gas arranged at the anode discharge connection. Furthermore, Electrolysis the system has a second heat exchanger and a third heat exchanger arranged downstream of at least one of the two catalysts in the flow direction at the anode discharge connection.

[0006] Thus, according to the invention, Electrolysis by using the residual gas from the synthesis process for producing synthetic hydrocarbons for catalytic combustion in the two catalysts of the system, ElectrolysisThe efficiency of the system is increased. The heat obtained during catalytic combustion is Electrolysis utilized by at least one heat exchanger within the system. The additional heat can be Electrolysis provided at various locations within the system, particularly at connections, in particular at the anode supply connection and / or the cathode supply connection, especially at supply connections, thereby increasing the efficiency of high-temperature steam electrolysis, in particular high-temperature co-electrolysis (Hochtemperatur-Co-Elektrolyse), which is carried out by Electrolyzer stack to produce synthetic gas, or in other words, syngas. For example, compared to the use of a single catalyst and parallel heat exchangers, the use of two catalysts has the special advantage that the same amount of heat can be supplied to the second and third heat exchangers at a lower catalyst temperature. It is also possible to achieve a higher air temperature and / or reactant temperature at the same outlet target temperature. These and other advantages of the present invention will be explained and become apparent in more detail below.

[0007] Within the scope of this specification, for the sake of simplicity, Electrolyzer stack the term "" is used. This means at least one Electrolyzer stack because, of course, Electrolysis there are a plurality of Electrolyzer stack provided within the system, and it can be contemplated that these can be optionally connected to each other, for example, connected to each other in series or in parallel. In that case, further Each electrolyzer stack each cathode part and each anode part of are fluid-technically connected in the manner described in this specification to the connection parts mentioned in this specification.

[0008] Electrolyzer stack can in particular be a solid oxide type Electrolyzer stack . Therefore, Electrolysis the system can in particular be a solid oxide type Electrolysis system or a solid oxide electrolysis cell system (also known as "Solid Oxide Electrolyzer Cell System" in English SOEC system). ElectrolysisOf the system Electrolyzer stack is to achieve the electrolysis of water (H2O) and carbon dioxide (CO2) , electricity electrolysis mode , at operates in particular in a co - electrolysis mode. Thereby inside the electrolyzer stack hydrogen gas (H2), carbon monoxide (CO), and oxygen (O2) can be produced by the electrolyte of. In that case, for producing synthesis gas Electrolyzer stack it is advantageous if is connected to a current supply source for providing a current from a renewable energy source. By using such a current supply source supplied from a renewable energy source, the high - temperature steam electrolysis operation can be made ecologically sustainable.

[0009] Within the scope of the present invention Electrolysis a system is in particular understood to be an electrolysis system, preferably a co - electrolysis system, and / or a reversible Electrolysis system. In a reversible Electrolysis system, advantageously, it can be switched between a fuel cell operation and an electrolysis operation.

[0010] For the above - mentioned reactions in the electrolysis operation, an anode gas, in particular air, especially fresh air or oxygen, is supplied to the anode part by an anode supply connection. By a cathode supply connection, a cathode gas, in particular carbon dioxide, is supplied to the cathode part. In that case, the cathode supply connection can be connected to various carbon dioxide sources. For example, it is possible to extract carbon dioxide from air, biogas processes, industrial exhaust gases, etc., and water can be supplied to the cathode supply part via a first additional supply connection for supplying water. For this purpose, a first additional supply connection which can be fluid - technologically coupled to the cathode supply connection or the cathode supply part by a first additional supply connection can supply water to the cathode supply part, preferably in the form of steam. Alternatively or additionally ElectrolysisWater can be evaporated in the system to form water vapor. Since the water vapor is supplied to the cathode supply unit, it can be regarded as part of the cathode gas. In some cases, the protective gas supplied to the cathode supply connection part is also supplied to the cathode supply unit, so it can be regarded as part of the cathode gas. The anode exhaust gas is discharged from the anode discharge part to the anode discharge connection part and then to the anode discharge connection part through the anode discharge connection part. The anode exhaust gas discharged at the anode discharge connection part contains, in particular Electrolysis exhaust discharged from the system or oxygen discharged, especially air with added oxygen, and combustion products of catalytic combustion of the residual gas mixed with the catalytic exhaust gas, i.e., the anode exhaust gas, downstream of the catalyst. These can be released, for example, from the anode discharge connection part into the ambient environment. In particular, the generated cathode exhaust gas, which is mainly synthesis gas containing hydrogen gas and carbon monoxide, is supplied from the cathode discharge part to the cathode discharge connection part. This cathode discharge connection part can be connected to a corresponding synthesis system having synthesis equipment to provide synthesis gas for producing synthetic hydrocarbons. In this synthesis process, typically not all of the synthesis gas can be converted. Furthermore, in the synthesis process, short-chain hydrocarbons are generated in addition to long-chain products. The unconverted part of the synthesis gas forms a gas mixture with the short-chain hydrocarbons, and in particular, a part of it is recycled to the synthesis equipment and a part is separated. This separated gas part is referred to herein as the residual gas. That is, surprisingly, this residual gas has a high calorific value and has been found to be advantageously usable for providing heat in high-temperature steam electrolysis, thereby in particular by the method according to the invention Electrolysis the efficiency of the system can be increased.

[0011] For example, in order to distinguish components or elements of the same kind or the same type, such as heat exchangers, shut-off members, partial paths, or bypass paths, etc., the components or elements of the same kind or the same type referred to in this specification are assigned consecutive numbers, and are referred to as the first component, the second component, the third component (or element), etc., that is, for example, the first heat exchanger, the second heat exchanger, etc. This numbered name is merely used to distinguish the components or elements of the same kind or the same type referred to in this specification, and in no way limits the scope of protection. For example, in a claim, when using the term a fourth component of a certain kind or a certain type, this does not necessarily presuppose the first, second, and third components of this kind or this type, apart from the cases where the first, second, and third components of this kind or this type are referred to in the claim.

[0012] The connection parts referred to in this specification are fluid flow connections, especially gas flow connections. These connection parts can be formed via various passages or lines, such as pipes or hoses, which are respectively connected to each other. As mentioned in this specification, various devices that affect the flow can be arranged at the connection parts.

[0013] As long as the terms the arrangement of the heat exchanger in the connection part and the thermal technical connection of the heat exchanger to another connection part are used in this specification, these features should be understood as synonymous based on the function of the heat exchanger. Because in each connection part, the heat from two flows is exchanged with each other by the heat exchanger, for example, in a countercurrent manner. To that extent, the heat exchanger is actually arranged at each of the two connection parts, and the heat exchanger also thermally technically connects the two connection parts to each other.

[0014] In this specification, when the term control or controlling is used, particularly in relation to a shut-off member, this is understood to mean open-loop control and / or closed-loop control. Even if this is not explicitly mentioned, in order to control, corresponding control electronics and control devices beyond the shut-off member, such as a flow meter for example, can be contemplated.

[0015] The shut-off members referred to in this specification are used, at least at the connection, to stop or allow the flow of the fluid flowing therethrough, in particular the flow of gas. It is also possible to control the flow rate depending on the type of shut-off member used. In that case, the shut-off member can be designed in various ways, for example as a valve, shut-off slider, shut-off cock or shut-off flap.

[0016] It is advantageous if two catalysts are coupled to different and branched partial paths of the residual gas supply connection. In this way, the residual gas flow to each of the two catalysts can be controlled. In other words, the amount of residual gas supplied to each of the two catalysts can be controlled. Therefore, the heat released to the heat exchanger arranged downstream of each catalyst can also be controlled.

[0017] For this purpose, advantageously, 5th and / or 6th the shut-off member can be arranged in at least one of the two partial paths. such It is particularly advantageous if the shut-off member is arranged in each of the partial paths. For example, a shut-off flap can be used as the shut-off member. This enables the residual gas flow to the catalyst and, accordingly, the amount of heat generated by catalytic combustion by the catalyst to be controlled easily but accurately.

[0018] For this purpose, it is advantageous if each of the two partial paths is connected to the anode discharge connection upstream of the catalyst supply of one of the two catalysts in order to mix the residual gas and the anode exhaust gas to form a residual gas anode exhaust gas mixture. Thus, the residual gas anode exhaust gas mixture is introduced into the catalyst and catalytically combusted. This not only optimizes the catalytic combustion but also enables the residual gas to be preheated for catalytic combustion by the warm anode exhaust gas from Electrolyzer stack thereby.

[0019] Advantageously, it can also be contemplated that the first catalyst of the two catalysts is arranged downstream of the second catalyst of the two catalysts in the flow direction of the anode discharge connection. Thus, the first catalyst is provided in the first catalyst stage and the second catalyst is provided in the second catalyst stage. In particular, in connection with the partial paths described above, Electrolysis each catalyst stage can be controlled individually, for example switched on or off, or the amount of residual gas supplied can be controlled as required for optimal operation of the system. Correspondingly, one of the second and third heat exchangers can be arranged downstream of the two catalysts in the flow direction at the anode discharge connection, and the other of the second and third heat exchangers can be arranged only downstream of the second catalyst in the flow direction at the anode discharge connection.

[0020] Similarly, it is advantageous if one of the second and third heat exchangers is thermally coupled to the anode supply connection. This enables the heat from the catalytic exhaust gas of one or both catalysts to be discharged to the anode supply connection and thereby warm the anode gas arriving at the anode supply, increasing the efficiency of high-temperature steam electrolysis.

[0021] Alternatively or additionally, it can be contemplated and is advantageous that one of the second and third heat exchangers is thermally coupled to the cathode supply connection. This enables heat from the catalytic exhaust gas of one or both catalysts to be discharged to the cathode supply connection and thereby warm the cathode gas arriving at the cathode supply, enhancing the efficiency of high-temperature steam electrolysis. Preferably, one of the second and third heat exchangers is used for thermal coupling with the anode supply connection and the other is used for thermal coupling with the cathode supply connection.

[0022] Furthermore, a fourth heat exchanger is arranged downstream of the second and third heat exchangers at the anode exhaust connection and is thermally coupled to a first additional supply connection, which advantageously connects the cathode supply connection or the cathode supply to a first additional supply link for supplying water or steam to the cathode supply. Thereby, the residual heat still contained in the catalytic exhaust gas after heat exchange in the second and third heat exchangers at the anode exhaust connection is used to heat the water or steam supplied to the first additional supply link, and thereby Electrolysis it can be utilized to further enhance the efficiency of the system.

[0023] Additionally or alternatively, it can be contemplated and is advantageous that a fifth heat exchanger is arranged downstream of the second and third heat exchangers in the flow direction at the anode exhaust connection and is thermally coupled to the anode supply connection. Thereby, the residual heat still contained in the exhaust gas after heat exchange in the second and third heat exchangers at the anode exhaust connection is used to heat the air transported at the anode supply connection, and thereby Electrolysis it can be utilized to further enhance the efficiency of the system.

[0024] Furthermore, it is advantageous if the first heat exchanger is arranged at the anode supply connection and is technically connected to the anode discharge connection upstream of the two catalysts in the flow direction. Thereby, especially in the first step, the heat of the anode exhaust gas from the anode discharge section, in particular the catalyst exhaust gas containing the discharged air, can be utilized to warm the anode gas, in particular the supplied air. In addition to warming the anode gas, this has the advantage that the anode exhaust gas in the anode section is cooled by heat transfer, so that the self-ignition temperature of the residual gas anode exhaust gas mixture generated by mixing the residual gas and the anode exhaust gas downstream of the first heat exchanger in the flow direction is lower. Because Electrolyzer stack in which oxygen diffuses from the cathode section to the anode section, the anode gas is very oxygen-rich with about 30% oxygen. Lowering it below the self-ignition temperature Electrolysis prevents a high heat load on the components of the system and is purposeful in that it ensures a controlled combustion by the subsequent catalyst.

[0025] In that case, a third bypass path connects the anode supply connection upstream of the first heat exchanger in the flow direction and the anode supply connection downstream of the first heat exchanger in the flow direction to each other, and a third shut-off member is arranged in the third bypass path bypassing the first heat exchanger, and / or at the anode supply connection, downstream of the branch from the anode supply connection to the third bypass path in the flow direction and upstream of the first heat exchanger, a fourth shut-off member is arranged. Thereby, at the anode supply connection, it becomes possible in a simple way for the supplied air to bypass the first heat exchanger. Furthermore, this enables a simple control of the temperature of the anode gas and the anode exhaust gas at each anode connection.

[0026] In that case, advantageously, a first heating device can be arranged in the third bypass path. The first heating device can in particular be an electric heater. In this way, Electrolyzer stack the temperature of the supplied anode gas can be further increased in order to operate at an optimal operating point.

[0027] Furthermore, advantageously, the anode discharge connection is upstream of at least one of the two catalysts in the flow direction, 1st and / or 2nd and is connected to the anode supply connection by a bypass path. In particular, the bypass path connected to the anode supply connection, such i.e., the first bypass path and the second bypass path, can be provided upstream of each of the two catalysts in the flow direction. In particular, in addition to the mixing that has already taken place in which the oxygen-rich exhaust of the anode exhaust gas from the anode discharge part is mixed with the residual gas, additional cold air for catalytic combustion can be introduced to the catalyst, whereby the catalyst can also be cooled. In that case, it is advantageous for a shut-off member to be arranged in the bypass path. Particularly advantageously, a first shut-off member is arranged in the first bypass path and a second shut-off member is arranged in the second bypass path. This makes it possible to control the amount of additional air supplied.

[0028] Furthermore, it is advantageous if at least one of the two catalysts is designed as an oxidation catalyst. In particular, both catalysts can be designed as oxidation catalysts. The oxidation catalyst can oxidize harmful substances such as carbon monoxide and hydrocarbons, but it cannot reduce nitrogen oxides. By using the oxidation catalyst, not only can the energy contained in the residual gas be utilized in the form of heat, but also the conversion of the hydrogen still present in the exhaust gas is achieved.

[0029] Furthermore, Electrolysis the system Electrolyzer stack produces synthesis gas from synthesis synthesis for producing hydrocarbons and it is advantageous if it further has a first additional supply connection for providing heated steam that is heated during the cooling in Electrolysis correspondingly, in order to optimize the efficiency of the system, not only the residual gas from the synthesis process but also the heated steam generated during the cooling in the synthesis process can be made available, whereby a double and synergistic efficiency optimization of high-temperature steam electrolysis is achieved.

[0030] The subject matter of the present invention further relates to a Electrolysis system and a synthesis system including synthesis equipment Electrolysis which is equipment. In that case, the cathode exhaust connection is fluidically connected to the synthesis equipment by a synthesis gas supply connection. Furthermore, the synthesis equipment Electrolyzer stack is configured to synthesize synthesis gas generated by Synthetic hydrocarbons produced from and supplied by the synthesis gas supply connection. Furthermore, the synthesis equipment is fluidically connected to the residual gas supply connection by a residual gas exhaust connection for providing residual gas.

[0031] Electrolysis The equipment is to be understood, within the scope of the present invention, in particular preferably as the entire equipment designed as a so-called "power-to-liquid equipment" or PtL equipment.

[0032] Therefore, the Electrolysis equipment according to the present invention provides the same advantages as those described in detail with reference to the Electrolysis system according to the present invention.

[0033] The subject matter of the present invention further relates to Electrolysis a method for generating synthesis gas by a Electrolysis system, in particular by a Electrolysis system according to the present invention, and more particularly by equipment according to the present invention, the method comprising: - supplying residual gas separated from a synthesis process in which synthesis gas is converted into hydrocarbons to two catalysts of the Electrolysis system; - catalytically combusting the residual gas by two catalysts of the Electrolysis system; - transferring the heat of the catalytic exhaust gas flow of the catalytic combustion of the two catalysts to anode gas and cathode gas respectively by two heat exchangers; - supplying anode gas, cathode gas, and an electric current to the Electrolysis of the Electrolyzer stack system; - generating synthesis gas from the supplied anode gas, cathode gas, and electric current by Electrolyzer stack ; is a method that includes.

[0034] Therefore, the method according to the present invention provides the same advantages as those described in detail according to the present invention. Regarding the battery device brought about.

[0035] In particular, the Electrolysis system according to the present invention and / or the Electrolysis equipment according to the present invention can be set or designed to execute the method according to the present invention.

[0036] Anode gas is understood to be the gas supplied to the anode part, that is, in particular air or oxygen. This does not include anode exhaust gas, that is, the exhaust gas discharged from the anode part, in particular air and / or oxygen. Cathode gas is understood to be the gas supplied to the cathode part, in particular carbon dioxide, water vapor and / or protective gas. This does not include cathode exhaust gas, that is, the synthetic gas discharged from the cathode part.

[0037] It has been found to be advantageous if the residual gas stream is distributed into two partial paths and the residual gas is supplied to each of the two catalysts by each of the two partial paths. This makes it possible to control the flow of residual gas to the catalyst and, accordingly, the heat release between the anode supply connection and the cathode supply connection. In particular, in that case, by appropriately controlling the residual gas flow in the two partial paths, it is possible to advantageously make the heat quantities of the two heat exchangers, and thus the anode supply connection and the cathode supply connection, substantially the same.

[0038] For this purpose, it is advantageous if the catalyst exhaust gas flow in the two partial paths is controlled by a shut-off member in each of the two partial paths downstream of the respective heat exchanger of each of the two partial paths.

[0039] It is also advantageous if the catalytic exhaust gas stream of one of the two catalysts is supplied to the other of the two catalysts by means of an anode exhaust connection. This makes it possible to utilize the catalytic exhaust gas stream of one catalyst for the catalytic combustion of the other catalyst with respect to its calorific value and thereby keep the efficiency high.

[0040] Furthermore, the catalytic exhaust gas stream, for further heat transfer, Electrolysis preferably flows through a fourth heat exchanger for heating the water or steam supplied to the system and / or through a fifth heat exchanger for heating the anode gas. This Electrolysis makes it possible to utilize the residual heat still remaining in the catalytic exhaust gas stream of the catalyst in order to further increase the efficiency of the system.

[0041] Furthermore, it is advantageous if the residual gas is mixed with the anode exhaust gas upstream of the catalyst in the flow direction Electrolyzer stack to form a residual gas - anode exhaust gas mixture. Thus, the temperature of the residual gas - anode exhaust gas mixture can be increased and the oxygen - rich air of the anode exhaust gas can be utilized for controlled catalytic combustion.

[0042] In that case, it is advantageous if the anode exhaust gas transfers heat to the supplied anode gas by means of the first heat exchanger before mixing with the residual gas. Thereby, the supplied anode gas containing air can be heated while the anode exhaust gas containing air can be cooled, in particular, below the auto - ignition temperature of the residual gas - anode gas mixture.

[0043] Furthermore, it is advantageous if anode gas is mixed into the residual gas - anode exhaust gas mixture. This can be done by means of the bypass paths mentioned above, in particular the first and second bypass paths. Thus, the air quantity can be further increased by the anode gas containing fresh air in the residual gas - anode exhaust gas mixture.

[0044] It has been found to be advantageous if the residual gas anode exhaust gas mixture has a temperature in the range of 300 to 550 °C, in particular in the range of 400 to 500 °C. This refers to the temperature of the catalyst supply part of the catalyst. The greatest increase in efficiency when producing synthesis gas could be observed in this temperature range.

[0045] It is advantageous if the catalytic exhaust gas of the catalytic combustion has a temperature in the range of 800 to 1000 °C, in particular in the range of 850 °C to 950 °C. This refers to the temperature of the catalyst discharge part of the catalyst. The greatest increase in efficiency when producing synthesis gas could be observed in this temperature range.

[0046] Advantageously, the produced synthesis gas is fed to a synthesis process, from which residual gas is separated and fed to the two catalysts.

[0047] Furthermore, it is advantageous if the synthesis process is a Fischer-Tropsch process. The combination of high-temperature steam electrolysis, in particular high-temperature co-electrolysis, and Fischer-Tropsch synthesis (abbreviated as FTS) has been found to be a particularly promising method for the production of various hydrocarbons. In FTS, the synthesis gas obtained from high-temperature co-electrolysis is converted into hydrocarbon molecules of various chain lengths, particularly at relatively low to moderate temperatures in the temperature range of 200 to 300 °C and at high pressures in the pressure range of particularly 10 to 30 bar, using in particular Co-based or Fe-based catalysts. The FTS process is accompanied by a large amount of heat generation. In order to be able to maintain the temperature within the specified temperature range, cooling can be carried out along the length of the reactor in the synthesis facility. In that case, the cooling can be carried out by evaporating water at the specified pressure level. Subsequently, the water vapor can be utilized for further process steps and, as described above, for high-temperature steam electrolysis itself by supplying the water vapor to the cathode gas. The distribution of the hydrocarbon chain lengths produced in FTS is represented by the chain growth probability (when the chain growth probability is high, large molecules and, accordingly, a shift in the direction of liquid fuels). However, in that case, the synthesis gas is not completely converted. Furthermore, depending on the chain growth probability, short-chain molecules that cannot be utilized as liquid fuels are produced. The unconverted synthesis gas and the short-chain hydrocarbons generated can be separated as residual gas in the product treatment. Part of the residual gas can be recycled to the FTS, but part of it needs to be removed. In particular, the removed part of the residual gas is utilized by the method according to the invention.

[0048] Other advantages, features and details of the invention will become apparent from the following description, in which embodiments of the invention are described in detail with reference to the drawings.

Brief Description of the Drawings

[0049] [Figure 1] It is a schematic diagram showing a first embodiment of the electrolysis facility according to the invention.

[0050] [Figure 2] It is a schematic diagram showing a second embodiment of the electrolysis facility according to the invention.

[0051] [Figure 3] It is a schematic diagram showing a third embodiment of the electrolysis facility according to the present invention.

[0052] [Figure 4] It is a schematic diagram showing an embodiment of the method according to the present invention.

Embodiments for Carrying Out the Invention

[0053] The same or functionally identical elements are denoted by the same reference numerals in FIGS. 1 to 4, respectively.

[0054] FIG. 1 shows Electrolyzer stack having 100 Electrolysis a system 10 and a synthesis system 20 having a synthesis facility 900. Electrolysis schematically shows the facility 30. Electrolysis The system 10 and the synthesis system 20 are fluidly coupled to each other, as will be described in more detail later.

[0055] In FIG. 1, by way of example, only one Electrolyzer stack 100 is shown. Nevertheless, it is possible to provide a plurality of Electrolyzer stack 100. Electrolyzer stack 100 has a cathode section 110 including a cathode supply section 112 and a cathode discharge section 114. Further, Electrolyzer stack 100 has an anode section 120 having an anode supply section 122 and an anode discharge section 124. Electrolyzer stack A current source 130 that provides a current from renewable energy is connected to 100. Electrolyzer stack 100 is here designed as a solid oxide type Electrolyzer stack and is used in an electrolysis mode for high-temperature co-electrolysis.

[0056] In that case, ElectrolysisIn system 10, anode gas in a fresh form is provided by anode gas connection part 202. The anode gas is supplied for electrolysis via anode supply connection part 200 which is fluidically connected to anode gas connection part 202 and anode supply part 122. Electrolyzer stack It is provided to 100. In that case, a filter device 204 for air filtration, particularly in the form of an air filter, and a blower 206 for transporting the anode gas are arranged at anode supply connection part 200.

[0057] At anode supply connection part 200, in the flow direction of the anode gas from anode gas connection part 202 to anode supply part 122, a first heat exchanger 224 is arranged downstream of filter device 204 and blower 206. The first heat exchanger 224 Electrolyzer stack is utilized for heat exchange with warm anode exhaust gas in the form of exhaust discharged from 100, particularly from anode part 120. For this purpose, the first heat exchanger 224 is thermally connected to anode discharge connection part 300 upstream of a second catalyst 418 in the form of an oxidation catalyst. Anode discharge connection part 300 fluidically connects anode discharge part 124 to anode discharge connection part 308.

[0058] The second catalyst 418 is arranged at anode discharge connection part 300 downstream of the first heat exchanger 224 in the flow direction of the anode exhaust gas and is fluidically connected to residual gas connection part 402 by residual gas supply connection part 400. Residual gas connection part 402 receives residual gas from synthesis facility 900 as will be described in more detail later. The residual gas provided to a second catalyst supply part 420 of the second catalyst 418 is mixed with the anode exhaust gas of anode discharge connection part 300 at the node point of residual gas supply connection part 400 and anode discharge connection part 300 to form a residual gas - anode exhaust gas mixture and is catalytically combusted by the second catalyst 418. High - temperature catalytic exhaust gas having a temperature in the range of 800 to 1000 °C, particularly about 950 °C, flows out from second catalyst discharge part 422.

[0059] The second bypass path 212 in which the second shut-off member 214 is arranged connects the anode supply connection portion 200 upstream of the first heat exchanger 224 in the flow direction of the anode gas to the anode discharge connection portion 300 upstream of the second catalyst supply portion 420, thereby further increasing the air ratio of the residual gas anode exhaust gas mixture before entering the second catalyst 418 and making it possible to further cool the residual gas anode exhaust gas mixture.

[0060] Along with this, a third bypass path 216 having a third shut-off member 218 is provided. This third bypass path connects the anode supply connection portion 200 upstream of the first heat exchanger 224 in the flow direction of the anode gas to the anode supply connection portion 200 downstream of the first heat exchanger 224 in the flow direction of the anode gas, thereby making it possible to control the temperature of the residual gas anode exhaust gas mixture upstream of the second catalyst 418 by adjusting the amount of anode gas flowing through the first heat exchanger 224. Further, a fourth shut-off member 222 is arranged upstream of the second heat exchanger 302 and downstream of the third bypass path 216 in the flow direction.

[0061] The high-temperature catalyst exhaust gas of the second catalyst 418 flows from the second catalyst discharge portion 422 at the anode discharge connection portion 300 through the second heat exchanger 302 thermally coupled to the anode supply connection portion 200. This makes it possible to release the heat of the catalyst exhaust gas of the second catalyst 418 to the anode gas upstream of the anode supply portion 122.

[0062] In addition to the second catalyst 418, ElectrolysisSystem 10 further includes another catalyst, herein referred to as the first catalyst 408. The first catalyst 408 is disposed at the anode exhaust connection 300 downstream of the second catalyst 418 in the flow direction, i.e., downstream of the second heat exchanger 302 and within the catalyst exhaust gas flow of the second catalyst 418. For this purpose, the residual gas supply connection 400 is divided into two individual sub-paths 404, 414, namely the first sub-path 404 and the second sub-path 414. A fifth shut-off member 406 is disposed in the first sub-path 404. A sixth shut-off member 416 is disposed in the second sub-path 414. As such, the shut-off members 406, 416 can control the amount of residual gas supplied to each of the two catalysts 408, 418 and, accordingly, the amount of heat released therefrom by the catalytic combustion with the catalyst exhaust gas. In that case, as already described above, the mixing of the residual gas and the anode exhaust gas takes place at the above-described node point upstream of the second catalyst supply section 420 of the second catalyst 418. Also upstream of the first catalyst supply section 410 of the first catalyst, at the node point where the anode discharge section 300 and the first sub-path 404 merge, a corresponding mixing of the residual gas with the catalyst exhaust gas, which herein is also referred to as the anode exhaust gas as it flows through the anode exhaust connection 300 and which is herein also referred to as the residual gas anode exhaust gas mixture, takes place.

[0063] In the anode exhaust connection part 300, a third heat exchanger 304 is arranged downstream of the first catalyst 408 and its first catalyst discharge part 412 in the flow direction. The third heat exchanger 304 is thermally coupled to the cathode supply connection part 500. The cathode supply connection part 500 fluidly connects the cathode supply connection part 502 to the cathode supply part 112. In the cathode supply connection part 500, cathode gas, especially carbon dioxide, is supplied from the cathode supply connection part 502 to the cathode supply part 112. In the cathode supply connection part 500, a seventh shut-off member 504 and an ejector 506 are arranged upstream of the cathode part 110 in the flow direction of the anode gas. Further, downstream of the ejector 506 in the flow direction of the anode gas, a second heating device 508 in the form of an electric heater is arranged here. The third heat exchanger 304 can warm the cathode gas with the heat from the catalyst exhaust gas of one or both of the catalysts 408, 418.

[0064] The first bypass path 208 where the first shut-off member 210 is arranged connects the anode supply connection part 200 upstream of the first heat exchanger 224, especially upstream of the branch to the second bypass path 212, in the flow direction of the anode gas, to the anode exhaust connection part 300 upstream of the first catalyst supply part 410, thereby making it possible to increase the air ratio of the residual gas anode exhaust gas mixture before it enters the first catalyst 408 and cool the residual gas anode exhaust gas mixture.

[0065] Therefore, ElectrolysisDue to the above-described arrangement of the catalysts 408, 418 in the system 10, it is possible to operate only one of the catalysts 408, 418 or both together, with the latter being preferred. Thus, the oxygen-rich exhaust in the anode exhaust gas is mixed with a first residual gas amount controllable by the sixth shut-off member 416, and a controlled catalytic combustion via the second catalyst 418, which functions as a first oxidation catalyst stage in that regard, and a temperature provision in the second heat exchanger 302, which functions as an air superheater for the air in the anode gas, can be achieved. On the other hand, the continuously oxygen-rich catalytic exhaust gas of the second catalyst 418 can be mixed with a second residual gas amount controllable by the fifth shut-off member 406, and a controlled catalytic combustion via the first catalyst 408, which functions as a second oxidation catalyst stage in that regard, and a temperature provision in the third heat exchanger 304, which functions as a reactant superheater for the cathode gas, can be achieved.

[0066] The two oxidation catalyst stages can ensure the same heat exchange (meaning the total mass flow through both heat exchangers 302, 304 and the same enthalpy amount at a lower temperature) at a lower oxidation catalyst target temperature, or vice versa. For example, in a single-stage system with the two heat exchangers 302, 304 arranged in parallel, there is also the advantage that higher air temperatures and reactant temperatures can be achieved at the same oxidation catalyst target temperature.

[0067] Instead of the arrangement shown in FIG. 1, Electrolysis this interconnection of the catalysts 408, 418 in the system 10 can also be such that the third heat exchanger 304 is arranged within the catalytic exhaust gas flow of the second catalyst 418 and the second heat exchanger 302 is arranged within the catalytic exhaust gas flow of the first catalyst 408. Insofar as the names of the same type or the same kind of components or elements are only used here to distinguish them from each other, it should be mentioned once again that it is by no means in accordance with a technically necessary order or the like.

[0068] In the embodiment of FIG. 1, in the anode exhaust connection part 300, the fourth heat exchanger 306 is located downstream of the second heat exchanger 302 in the flow direction of the catalytic exhaust gas. The fourth heat exchanger 306 is thermally coupled to a first additional supply connection part 700 that fluid-technologically connects a first additional supply connection part 702 to the cathode supply connection part 500. From the first additional supply connection part 702, water or steam is provided for high-temperature co-electrolysis, which is heated by the fourth heat exchanger 306 and flows to the cathode supply connection part 500.

[0069] The cathode exhaust gas in the form of synthesis gas containing hydrogen and carbon monoxide generated by high-temperature co-electrolysis is discharged to the synthesis system 20 by a cathode exhaust connection part 600 that fluid-technologically connects the cathode discharge part 114 to the cathode discharge connection part 612. In that case, two heat exchangers 608, 610, namely the sixth heat exchanger 608 and the seventh heat exchanger 610, are thermally arranged in the cathode exhaust connection part 600, transferring heat from the synthesis gas to the cathode gas, thereby Electrolysis To increase the efficiency of the system 10, it is thermally coupled to the cathode supply connection part 500.

[0070] The fourth bypass path 602 leads from the cathode exhaust part 600 to the ejector 506. A nozzle 604, particularly a Venturi nozzle, and an eighth shut-off member 606, particularly a valve, are arranged in the fourth bypass path 602.

[0071] The second additional supply connection part 800 fluid-technologically connects a second additional supply connection part 802 for supplying a protective gas to the cathode supply connection part 500 upstream of the seventh shut-off member 504 in the flow direction of the cathode supply connection part 500.

[0072] The anode gas containing air and the cathode gas containing carbon dioxide, steam and protective gas are supplied in the manner described above. Electrolyzer stackIn the electrolysis mode by high-temperature co-electrolysis, 100 generates cathode exhaust gas in the form of synthesis gas, which contains hydrogen and carbon monoxide, and anode gas containing exhaust. The anode exhaust gas is catalytically combusted by two catalysts 408, 418 together with the residual gas, whereby the catalytic exhaust gas is Electrolysis separated from the system 10 at the anode discharge connection 308.

[0073] The synthesis gas is provided to the synthesis facility 900 of the synthesis system 20 by a synthesis gas supply connection 906 that fluid-technologically connects the synthesis supply section 902 of the synthesis facility 900 to the cathode discharge connection 612. The synthesis gas is converted into synthetic hydrocarbons through a synthesis process, particularly a Fischer-Tropsch synthesis process, in a reactor not explicitly shown therein. The hydrocarbons are discharged via a hydrocarbon discharge connection 908 that is fluid-technologically connected to the synthesis discharge section 904. However, the synthesis gas and short-chain hydrocarbons that were not converted in the synthesis process remain, a part of which can be returned and supplied to the synthesis process, and a part can be discharged as residual gas to the residual supply connection 402 by the residual gas discharge connection 910, insofar as these are fluid-technologically coupled to each other.

[0074] Figure 2 shows a variant of the embodiment of the facility 30 in Electrolysis Figure 1. Strictly speaking, in Figure 2, the fourth heat exchanger 306 is omitted. Instead, at the anode discharge connection 300, a fifth heat exchanger 310 is installed downstream of the two heat exchangers 302, 304 in the flow direction, which is thermally technologically coupled to the anode supply connection 200, particularly downstream of the blower 206 and upstream of the first heat exchanger 224 in the flow direction of the anode gas. This makes it possible to alternatively provide the residual heat of the anode exhaust gas or the catalytic exhaust gas for the anode gas. Nevertheless, it is of course also possible to provide both the fourth heat exchanger 306 and the fifth heat exchanger 310 in series connection or parallel connection with corresponding shut-off members and bypass paths.

[0075] Furthermore, any configuration of the illustrated heat exchangers 224, 302, 304, 306, 310, 608, 610 is possible, which means that these heat exchangers can be used individually or in any selection in the Electrolysis system 10, and thus Electrolysis it is not necessary for the system 10 to include all of the heat exchangers 224, 302, 304, 306, 310, 608, 610.

[0076] FIG. 3 shows a variant of the installation 30 of the embodiment of FIG. 1, in which the synthesis installation 20 has been Electrolysis modified. In that case, a cooling device is shown in the synthesis installation 900, which in particular cools the corresponding reactor within the synthesis installation 900. In that case, steam is used to cool a reaction that proceeds with a large amount of heat generation during the synthesis process. The steam thus heated is advantageously provided to the corresponding third additional supply connection by the dashed line fluidically connected to the first additional supply connection 702, and thus advantageously provided to the first additional supply connection 702. to the part

[0077] FIG. 4 shows Electrolysis a method 1000 for generating synthesis gas by the system 10, which has already been described with reference to FIGS. 1 to 3 based on the installation 30. In that case, the method 1000 is shown purely schematically based on its method steps 1002, 1004, 1006, 1008, 1010, and additional method steps not explicitly shown can be added. Electrolysis

[0078] In the first method step 1002 of the method 1000, residual gas is separated from the synthesis process proceeding in the synthesis installation 900 in which the synthesis gas from the cathode discharge connection 612 is converted into hydrocarbons. The residual gas is provided to the residual gas supply connection 402 by the residual gas discharge connection 910, and thus Electrolysis is provided to two catalysts 408, 418 by the partial paths 404, 414 of the residual gas supply connection 400 of the system 10.

[0079] In the second method step 1004 of the method 1000, the catalytic combustion of the residual gas is carried out by two catalysts 408, 418. The corresponding catalyst exhaust gas flows out from their catalyst discharge parts 412, 422. The catalyst exhaust gas can have a temperature in the range of 800 to 1000 °C. As can be seen in FIGS. 1 to 3, the upstream residual gas of the second catalyst 418 can be pre-mixed with the anode exhaust gas, that is, Electrolyzer stack the exhaust from 100, and optionally, by the second bypass passage 212, further mixed with the anode gas, that is, the fresh gas, so that a residual gas - anode exhaust gas mixture flows into the second catalyst supply part 420. As can be seen in FIGS. 1 to 3, the residual gas can also be pre-mixed with the anode exhaust gas, that is, the oxygen-rich catalyst exhaust gas from the second catalyst 418, and optionally, by the first bypass passage 208, mixed with the anode gas, that is, the fresh gas, upstream of the first catalyst 408, so that a residual gas - anode exhaust gas mixture flows into the first catalyst supply part 410. The residual gas - anode exhaust gas mixture can each have a temperature in the range of 300 to 550 °C.

[0080] In the third method step 1006 of the method 1000, the heat of the catalyst exhaust gas flow of the two catalysts 408, 418 for catalytic combustion is transferred to the anode gas of the anode supply connection part 200 and the cathode gas of the cathode supply connection part 500 by at least the heat exchangers 302, 304, and preferably, further by the fourth heat exchanger 306 and / or the fifth heat exchanger 310.

[0081] The anode gas and the cathode gas thus heated are supplied to 100 under the supply of current in the fourth method step 1008 of the method 1000. Electrolysis of the system 10 Electrolyzer stack is supplied to 100. Further, in the fifth method step 1010, synthesis gas can be generated by 100 from the supplied anode gas, cathode gas, and current. Electrolyzer stack In that case, the method steps 1002 to 1010 of the method 1000 are continuously executed as indicated by the arrows from the method step 1010 to the method step 1002.

[0082] ​

[0083] The description of the above embodiment only explains the present invention within the scope of exemplification. (Other possible items) (Item 1) An electrolysis system (10) comprising - An electrolyzer stack (100) having a cathode part (110) including a cathode supply part (112) and a cathode discharge part (114), and an anode part (120) including an anode supply part (122) and an anode discharge part (124); - An anode gas connection part (202) for supplying anode gas to the anode part (120), fluidically coupled to the anode supply part (112) by an anode supply connection part (200); - An anode discharge connection part (308) for discharging anode exhaust gas generated by the electrolyzer stack (100), fluidically coupled to the anode discharge part (124) by an anode discharge connection part (300); - A cathode supply connection part (502) for supplying cathode gas to the cathode part (110), fluidically coupled to the cathode supply part (112) by a cathode supply connection part (500); - A cathode exhaust connection part (600) fluidly coupled to the cathode exhaust part (114), a cathode exhaust connection part (612) for discharging the synthesis gas generated by the electrolysis cell stack (100), in an electrolysis system comprising: The electrolysis system (10) is - A residual gas supply connection part (402) for providing residual gas separated during the synthesis process for generating synthetic hydrocarbons from the synthesis gas generated by the electrolysis cell stack (100); - Two catalysts (408, 418) fluidly coupled to the residual gas supply connection part (402) by a residual gas supply connection part (400) and catalytically burning the residual gas disposed in the anode exhaust connection part (300); - In the anode exhaust connection part (300), a second heat exchanger (302) and a third heat exchanger (304) disposed downstream of at least one of the two catalysts (408, 418) in the flow direction; Further comprising This electrolysis system. (Item 2) The two catalysts (408, 418) are coupled to different and distribution sub-paths (404, 414) of the residual gas supply connection part (400), the electrolysis system (10) according to item 1. (Item 3) At least one of the two sub-paths (404, 414) is provided with a fifth and / or sixth shut-off member (406, 416), the electrolysis system (10) according to item 2. (Item 4) In order to mix the residual gas and the anode exhaust gas to form a residual gas anode exhaust gas mixture, each of the two sub-paths (404, 414) is fluidly connected to the anode exhaust connection part (300) upstream of one of the catalyst supply parts (410, 420) of the two catalysts (408, 418), the electrolysis system (10) according to item 2 or 3. (Item 5) The first catalyst (408) of the two catalysts (408, 418) is disposed downstream of the second catalyst (418) of the two catalysts (408, 418) in the flow direction of the anode exhaust connection part (300), the electrolysis system (10) according to any one of items 1 to 4. (Item 6) One of the second heat exchanger and the third heat exchanger (302, 304) is thermally coupled to the anode supply connection part (200), the electrolysis system (10) according to any one of items 1 to 5. (Item 7) The electrolysis system (10) according to any one of items 1 to 6, wherein one of the second heat exchanger and the third heat exchanger (302, 304) is thermally coupled to the cathode supply connection (500). (Item 8) A fourth heat exchanger (306) is arranged downstream of the second heat exchanger and the third heat exchanger (302, 304) in the flow direction at the anode discharge connection (300), and is thermally coupled to a first additional supply connection (700), and the first additional supply connection connects the cathode supply connection (500) or the cathode supply unit (112) to a first additional supply connection part (702) for supplying water or steam to the cathode supply unit (112). The electrolysis system (10) according to any one of items 1 to 7. (Item 9) A fifth heat exchanger (310) is arranged downstream of the second heat exchanger and the third heat exchanger (302, 304) in the flow direction at the anode discharge connection (300), and is thermally coupled to the anode supply connection (200). The electrolysis system (10) according to any one of items 1 to 8. (Item 10) The first heat exchanger (224) is arranged at the anode supply connection (200) and is thermally coupled to the anode discharge connection (300) upstream of the two catalysts (408, 418) in the flow direction. The electrolysis system (10) according to any one of items 1 to 9. (Item 11) A third bypass path (216) connects the anode supply connection (200) upstream of the first heat exchanger (224) in the flow direction and the anode supply connection (200) downstream of the first heat exchanger (224) in the flow direction, and a third shut-off member (218) is arranged in the third bypass path (216) bypassing the first heat exchanger (224), and / or at the anode supply connection (200), a fourth shut-off member (222) is arranged downstream of the branch from the anode supply connection (200) to the third bypass path (216) and upstream of the first heat exchanger (224) in the flow direction. The electrolysis system (10) according to item 10. (Item 12) A first heating device (220) is arranged in the third bypass path (216). The electrolysis system (10) according to item 11. (Item 13) The anode discharge connection part (300) is connected to the anode supply connection part (200) by the first and / or second bypass paths (208, 212) upstream of at least one of the two catalysts (408, 318) in the flow direction, and the electrolysis system (10) according to any one of items 1 to 12. (Item 14) The electrolysis system (10) according to any one of items 1 to 13, wherein at least one of the two catalysts (404) is designed as an oxidation catalyst. (Item 15) The electrolysis system (10) further has a first additional supply connection part (702) for providing heated steam, which is heated during cooling in synthesis for producing synthetic hydrocarbons from the synthesis gas generated by the electrolysis cell stack (100), and the electrolysis system (10) according to any one of items 1 to 14. (Item 16) An electrolysis facility (30) comprising the electrolysis system (10) according to any one of items 1 to 15 and a synthesis system (20) having a synthesis facility (900), - The cathode discharge connection part (612) is fluid-technologically coupled to the synthesis facility (900) by a synthesis gas supply connection part (906), - The synthesis facility (900) is set to synthesize synthetic hydrocarbons produced from the synthesis gas generated by the electrolysis cell stack (100) and supplied by the synthesis gas supply connection part (906), - The synthesis facility (900) is fluid-technologically coupled to the residual gas supply connection part (402) by a residual gas discharge connection part (910) for providing residual gas, and the electrolysis facility. (Item 17) A method (1000) for generating synthesis gas by an electrolysis system (10), - Supplying the residual gas separated from the synthesis process in which the synthesis gas is converted into hydrocarbons to the two catalysts (408, 418) of the electrolysis system (10); - Catalytically burning the residual gas by the two catalysts (408, 418) of the electrolysis system (10); - Transferring the heat of the catalytic exhaust gas flow of the catalytic combustion of the two catalysts (408, 418) to the anode gas and the cathode gas respectively by two heat exchangers (302, 304); - Supplying the anode gas, the cathode gas, and an electric current to the electrolysis cell stack (100) of the electrolysis system (10). -generating the synthesis gas by the electrolysis cell stack (100) from the supplied anode gas, cathode gas, and current. (Item 18) The method (1000) according to item 17, wherein the residual gas is distributed into two partial paths (404, 414), and the residual gas is supplied to each of the two catalysts (408, 418) by each of the two partial paths (404, 414). (Item 19) The method (1000) according to item 18, wherein the supply of the residual gas to each of the two catalysts (408, 418) is controlled by one shut-off member (406, 416) in each of the two partial paths (404, 414). (Item 20) The method (1000) according to any one of items 17 to 19, wherein an exhaust gas flow of one of the two catalysts (408, 418) is supplied to the other of the two catalysts (408, 418) by the anode discharge connection part (300). (Item 21) The method (1000) according to any one of items 17 to 20, wherein the exhaust gas flow of the catalyst passes through a fourth heat exchanger (306) for heating water or steam supplied by the electrolysis system (10) for further heat transfer and / or through a fifth heat exchanger (310) for heating the anode gas. (Item 22) The method (1000) according to any one of items 17 to 21, wherein the residual gas is mixed with the anode exhaust gas of the electrolysis cell stack (100) upstream of the catalyst (408, 418) in the flow direction to form a residual gas - anode exhaust gas mixture. (Item 23) The method (1000) according to item 22, wherein the anode exhaust gas transfers heat to the supplied anode gas by a first heat exchanger (224) before mixing with the residual gas. (Item 24) The method (1000) according to item 22 or 23, wherein anode gas is mixed into the residual gas - anode exhaust gas mixture. (Item 25) The method (1000) according to any one of items 22 to 24, wherein the residual gas - anode exhaust gas mixture has a temperature in the range of 300 to 550 °C. (Item 26) The method (1000) according to any one of items 17 to 25, wherein the exhaust gas of the catalytic combustion has a temperature in the range of 800 to 1000 °C. (Item 27) The method (1000) according to any one of items 17 to 26, wherein the generated synthesis gas is supplied to the synthesis process, the residual gas is separated from the synthesis process, and is supplied to the two catalysts (404). (Item 28) The method (1000) according to any one of items 17 to 27, wherein the synthesis process is a Fischer-Tropsch process.

Explanation of Symbols

[0084] 10 Electrolysis System 20 Synthesis system 30 Electrolysis Facility 100 Electrolytic cell stack 110 Cathode section 112 Cathode supply section 114 Cathode discharge section 120 Anode section 122 Anode supply section 124 Anode discharge section 130 Current supply source 200 Anode supply connection section 202 Anode gas connection section 204 Filter device 206 Blower 208 First bypass path 210 First shut-off member 212 Second bypass path 214 Second shut-off member 216 Third bypass path 218 Third shut-off member 222 Fourth shut-off member 224 First heat exchanger 300 Anode discharge connection section 302 Second heat exchanger 304 Third heat exchanger 306 Fourth heat exchanger 308 Anode discharge connection section 310 Fifth heat exchanger 400 Residual gas supply connection section 402 Residual gas supply connection section 404 First partial path 406 Fifth shut-off member 408 First catalyst 410 First catalyst supply section 412 First catalyst discharge section 414 Second partial path 416 Sixth shut-off member 418 Second catalyst 420 Second catalyst supply section 422 Second catalyst discharge section 500 Cathode supply connection section 502 Cathode supply connection part 504 Seventh shut-off member 506 Ejector 508 Second heating device 600 Cathode discharge connection section 602 Fourth bypass path 604 Nozzle 606 Eighth shut-off member 608 Sixth heat exchanger 610 Seventh heat exchanger 612 Cathode discharge connection part 700 First additional supply connection section 702 First additional supply connection part 800 Second additional supply connection section 802 Second additional supply connection part 900 Synthesis equipment 902 Synthesis supply section 904 Synthesis discharge section 906 Synthesis gas supply connection section 908 Hydrocarbon discharge connection section 910 Residual gas discharge connection Part 1000 Method 1002 First method step 1004 Second method step 1006 Third method step 1008 Fourth method step 1010 Fifth method step

Claims

1. A fuel cell system (10), comprising: - A fuel cell stack (100) having a cathode section (110) including a cathode supply section (112) and a cathode discharge section (114), and an anode section (120) including an anode supply section (122) and an anode discharge section (124); - An anode gas connection section (202) for supplying anode gas to the anode section (120), which is fluid-technologically connected to the anode supply section (112) by an anode supply connection section (200); - An anode discharge connection section (308) for discharging anode exhaust gas generated by a fuel cell stack (20), which is fluid-technologically connected to the anode discharge section (124) by an anode discharge connection section (300); - A cathode supply connection section (502) for supplying cathode gas to the cathode section (110), which is fluid-technologically connected to the cathode supply section (112) by a cathode supply connection section (500); - A cathode discharge connection section (612) for discharging synthesis gas generated by the fuel cell stack (20), which is fluid-technologically connected to the cathode discharge section (114) by a cathode discharge connection section (600), in a fuel cell system comprising: The fuel cell system (10) further comprises: - A residual gas supply connection section (402) for providing residual gas separated during the synthesis of the synthesis gas generated by the fuel cell stack (100); - Two catalysts (408, 418) fluid-technologically connected to the residual gas supply connection section (402) by a residual gas supply connection section (400) and arranged at the anode discharge connection section (300) for catalytically burning the residual gas; - A second heat exchanger (302) and a third heat exchanger (304) arranged downstream of at least one of the two catalysts (408, 418) in the flow direction at the anode discharge connection section (300). The fuel cell system further comprises: A fuel cell system.

2. The fuel cell system (10) according to claim 1, wherein the two catalysts (408, 418) are connected to different distribution sub-paths (404, 414) of the residual gas supply connection section (400).

3. The fuel cell system (10) according to claim 2, wherein a shut-off member (406, 416) is arranged in at least one of the two sub-paths (404, 414).

4. For mixing the residual gas and the anode exhaust gas to form a residual gas - anode exhaust gas mixture, each of the two partial paths (404, 414) is fluid - technically connected to the anode discharge connection part (300) upstream of one of the catalyst supply parts (410, 420) of the two catalysts (408, 418), the fuel cell system (10) according to claim 2 or 3.

5. The first catalyst (408) of the two catalysts (408, 418) is arranged downstream of the second catalyst (418) of the two catalysts (408, 418) in the flow direction of the anode discharge connection part (300), the fuel cell system (10) according to any one of claims 1 to 4.

6. One of the second heat exchanger and the third heat exchanger (302, 304) is thermally - technically coupled to the anode supply connection part (200), the fuel cell system (10) according to any one of claims 1 to 5.

7. One of the second heat exchanger and the third heat exchanger (302, 304) is thermally - technically coupled to the cathode supply connection part (500), the fuel cell system (10) according to any one of claims 1 to 6.

8. A fourth heat exchanger (306) is arranged downstream of the second heat exchanger and the third heat exchanger (302, 304) in the flow direction at the anode discharge connection part (300) and is thermally - technically coupled to a first additional supply connection part (700), and the first additional supply connection part connects the cathode supply connection part (500) or the cathode supply part (112) to a first additional supply connection part (702) for supplying water or steam to the cathode supply part (112), the fuel cell system (10) according to any one of claims 1 to 7.

9. A fifth heat exchanger (310) is arranged downstream of the second heat exchanger and the third heat exchanger (302, 304) in the flow direction at the anode discharge connection part (300) and is thermally - technically coupled to the anode supply connection part (200), the fuel cell system (10) according to any one of claims 1 to 8.

10. The fuel cell system (10) according to any one of claims 1 to 9, wherein a first heat exchanger (224) is arranged at the anode supply connection part (200) and is thermally coupled to the anode discharge connection part (300) upstream of the two catalysts (408, 418) in the flow direction.

11. A third bypass path (216) connects the anode supply connection part (200) upstream of the first heat exchanger (224) in the flow direction and the anode supply connection part (200) downstream of the first heat exchanger (224) in the flow direction to each other. A third shut-off member (218) is arranged in the third bypass path (216) bypassing the first heat exchanger (224), and / or at the anode supply connection part (200), downstream of the branch from the anode supply connection part (200) to the third bypass path (216) in the flow direction and upstream of the first heat exchanger (224), a fourth shut-off member (222) is arranged. The fuel cell system (10) according to claim 10.

12. The fuel cell system (10) according to claim 11, wherein a first heating device (220) is arranged in the third bypass path (216).

13. The anode discharge connection part (300) is connected to the anode supply connection part (200) by bypass paths (208, 212) upstream of at least one of the two catalysts (408, 318) in the flow direction. The fuel cell system (10) according to any one of claims 1 to 12.

14. The fuel cell system (10) according to any one of claims 1 to 13, wherein at least one of the two catalysts (404) is designed as an oxidation catalyst.

15. The fuel cell system (10) further has a first additional supply connection part (702) for providing heated steam that is heated during cooling in the synthesis process of the synthesis gas generated by the fuel cell stack (100). The fuel cell system (10) according to any one of claims 1 to 14.

16. A fuel cell facility (30) comprising the fuel cell system (10) according to any one of claims 1 to 15 and a synthesis system (20) having synthesis equipment (900), - A cathode discharge connection part (612) is fluidly coupled to the synthesis equipment (900) by a synthesis gas supply connection part (906). - The synthesis equipment (900) is configured to synthesize synthesis gas generated by the fuel cell stack (100) and supplied by the synthesis gas supply connection part (906). - The synthesis equipment (900) is a fuel cell equipment that is fluidically connected to the residual gas supply connection part (402) by a residual gas discharge connection part (910) for providing residual gas.

17. A method (1000) for generating synthesis gas by a fuel cell system (10), - A step of supplying residual gas separated from a synthesis process in which synthesis gas is converted into hydrocarbons to two catalysts (408, 418) of the fuel cell system (10); - A step of catalytically burning the residual gas by the two catalysts (408, 418) of the fuel cell system (10); - A step of transferring the heat of the catalytic exhaust gas flow of the catalytic combustion of the two catalysts (408, 418) to the anode gas and the cathode gas respectively by two heat exchangers (302, 304); - A step of supplying the anode gas, the cathode gas, and current to the fuel cell stack (100) of the fuel cell system (10); - A method including a step of generating the synthesis gas by the fuel cell stack (100) from the supplied anode gas, cathode gas, and current.

18. The method (1000) according to claim 17, wherein the residual gas is distributed to two partial paths (404, 414), and the residual gas is supplied to each of the two catalysts (408, 418) by each of the two partial paths (404, 414).

19. The method (1000) according to claim 18, wherein the supply of the residual gas to each of the two catalysts (408, 418) is controlled by one shut-off member (406, 416) in each of the two partial paths (404, 414).

20. The method (1000) according to any one of claims 17 to 19, wherein one of the catalytic exhaust gas flows of the two catalysts (408, 418) is supplied to the other of the two catalysts (408, 418) by an anode discharge connection part (300).

21. The catalyst exhaust gas stream flows through a fourth heat exchanger (306) for warming water or steam supplied by the fuel cell system (10) for further heat transfer and / or through a fifth heat exchanger (310) for warming the anode gas, the method (1000) according to any one of claims 17 to 20.

22. The residual gas is mixed with the anode exhaust gas of the fuel cell stack (100) upstream of the catalyst (408, 418) in the flow direction to form a residual gas anode exhaust gas mixture, the method (1000) according to any one of claims 17 to 21.

23. The anode exhaust gas transfers heat to the supplied anode gas by a first heat exchanger (224) before mixing with the residual gas, the method (1000) according to claim 22.

24. Anode gas is mixed into the residual gas anode exhaust gas mixture, the method (1000) according to claim 22 or 23.

25. The residual gas anode exhaust gas mixture has a temperature in the range of 300 to 550 °C, the method (1000) according to any one of claims 22 to 24.

26. The catalyst exhaust gas of the catalytic combustion has a temperature in the range of 800 to 1000 °C, the method (1000) according to any one of claims 17 to 25.

27. The produced synthesis gas is supplied to the synthesis process, the residual gas is separated from the synthesis process and supplied to the two catalysts (404), the method (1000) according to any one of claims 17 to 26.

28. The synthesis process is a Fischer-Tropsch process, the method (1000) according to any one of claims 17 to 27.

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