Methanation facility for producing methane and / or methanol and method for operating such a methanation facility

Abstract

The present disclosure relates to a methanation facility (100) for producing methane (8) and / or methanol and to a method for operating the methanation facility (100), the methanation facility (100) comprises a methane production unit (1) with a methanation reactor (25) configured to produce the methane (8) and / or the methanol by an exothermic reaction, thereby releasing reaction thermal energy (150), the methanation facility (100) further comprises a power source (109) configured to generate electric energy (3), which is used by the methane production unit (1) during its operation, and a thermal energy storage unit (120), which comprises a thermal circuit (121) and is configured for receiving and storing the reaction thermal energy (150) from the methanation reactor (25), wherein the thermal energy storage unit (120) is further configured to provide stored thermal energy (152) back to the methane production unit (1) during its operation.

Description

[0001] P28902PC00 23 Oktober 2025

[0002] 1 / 30

[0003] METHANATION FACILITY FOR PRODUCING METHANE AND / OR METHANOL AND METHOD FOR OPERATING SUCH A METHANATION FACILITY

[0004] FIELD OF THE DISCLOSURE

[0005] The present disclosure relates to a methanation facility for producing methane and I or methanol, the methanation facility comprising at least a methanation reactor, a power source and a thermal energy storage unit. The present disclosure further relates to a method for operating a methanation facility comprising at least a methanation reactor, a power source and a thermal energy storage unit for producing methane and I or methanol.

[0006] BACKGROUND OF THE DISCLOSURE

[0007] Methanation plants are designed to produce methane and I or methanol as an alternative source of these products with respect to natural occurrences. Natural occurrences include e.g. gas and oil fields, which are used to extract the above-mentioned products. These products comprise carbon dioxide, which is released in the atmosphere when these products are used. E.g. the burning of methane (natural gas, natural gas liquids or liquefied petroleum gas) produces heat and carbon dioxide. This carbon dioxide gathers in the earth’s atmosphere and is as greenhouse gas jointly responsible for the man-made climate change.

[0008] Nevertheless, natural gas plays a huge role in the industrial energy demand. Many industries rely on natural gas, e.g. for heat production. Further, natural gas is also used as a heat source for individual homes. Reducing the consumption of natural gas is one of P28902PC00 23 Oktober 2025

[0009] 2 / 30 the world population targets to reduce or mitigate the negative impacts of the man-made climate change.

[0010] A part of the solution could be to reduce the natural gas consumption or to replace it with other gases like green hydrogen. Nevertheless, the handling of hydrogen is extremely challenging and it cannot be fed into the existing gas pipeline system of countries or regions. Hydrogen would require a completely new pipeline system, which is extremely expensive.

[0011] Another option could be to use green natural gas, in particular, green methane or green methanol (synthetic or substitute natural gas - SNG). Green natural gas could be defined in that is has been synthesized, in particular via the sabatier-process, using renewable energy and I or renewable base products for the synthesis. The renewable energy may be provided via solar, nuclear or wind power plants etc. and the renewable base products are e.g. provided as waste or by-products from other processes. Alternatively, water may also be supplied from standard water grid.

[0012] The synthesis of methane is a complex procedure, which requires a plurality of components and input products. Further, the known methanation plants need preferably a constant energy supply and product inflow for an optimized output. The problem with renewable energy, e.g. from wind and solar power plants, is that the supply is not as constant as a conventional energy source like from a coal power plant. The production of green gas therefore requires new devices and methods of controlling the methanation plant in order to dynamically and efficiently operate the methanation facility for the desired green methane production. P28902PC00 23 Oktober 2025

[0013] 3 / 30

[0014] SUMMARY OF THE DISCLOSURE

[0015] It is an object of the present disclosure to provide a methanation facility for producing methane and I or methanol and to provide a method for operating the methanation facility, which address at least one of the disadvantages of the known methanation facilities of the respective methods. It is in particular an object of the present disclosure to provide a methanation facility and a method for operating the methanation facility for efficiently producing methane and I or methanol, in particular green methane and I or green methanol.

[0016] According to the present disclosure, these objects are addressed by the features of the independent claims. In addition, advantageous embodiments follow from the dependent claims, figures and the description.

[0017] According to the present disclosure, a methanation facility for producing methane and I or methanol is specified. The methanation facility comprises a methane production unit. The methane production unit is the portion or area of the methanation facility, which is configured to produce the methane and I or methanol. The methanation facility may further comprise additional components, e.g. peripheral units or auxiliary units, not forming part of the methane production unit.

[0018] The methane production unit comprises at least one methanation reactor, which is configured to produce the methane and I or the methanol by an exothermic reaction, thereby releasing reaction thermal energy. Producing methane and I or methanol is a strong exothermic reaction, which releases thermal energy or heat. This thermal energy should be removed from the reactor such that the reactor is kept within its desired working temperature range for increasing the product quality and the product yield. P28902PC00 23 Oktober 2025

[0019] 4 / 30

[0020] The methanation facility further comprises a power source configured to provide electric energy or electricity, which is at least partially used directly by the methane production unit during its operation. The operation of the methane production unit requires electric energy for its operation, which is at least partially provided by the power source. The power source may be a connection to the general power grit and / or a connection to a power plant or a power plant itself. The power source, which does according to the present determination not form part of the methane production unit, is configured to provide electric energy for the operation of the methane production unit and I or other components of the methanation facility.

[0021] The methanation facility further comprises a thermal energy storage unit, which is configured to store thermal energy. The thermal energy storage unit comprises a thermal circuit using a thermal working fluid. The thermal working fluid is the medium, which is configured to store the thermal energy, and which is further configured to transport the thermal energy from point A to point B. The thermal energy storage unit is further configured to receive and store the reaction thermal energy from the methanation reactor. In other words, the reaction thermal energy released during the synthesis of methane is at least partially transported to and stored by the thermal energy storage unit. The thermal energy storage unit is further configured to provide the stored thermal energy back to the methane production unit during its operation. The thermal energy storage unit may comprise one or a plurality of thermal circuits using the same or different working fluids.

[0022] The methanation facility according to the present disclosure enables that the reaction thermal energy released by the methanation reactor is reused or recycled via the thermal energy storage unit, which stores and provides the received thermal energy back to the methane production unit. Further, having the power source as a portion of the methanation facility increases its overall efficiency and controllability. Overall, the methanation facility according to the present disclosure enables that the production of methane and / P28902PC00 23 Oktober 2025

[0023] 5 / 30 or methanol is realizable more efficiently compared to conventional methane production facilities.

[0024] It is possible to further increase the efficiency of the methanation facility when the thermal energy storage unit is further configured for receiving and storing excess electric energy from the power source, which is not directly used by the methane production unit. In other words, excess electric energy from the power source, which is currently not required by the methane production unit for its operation, is provided to the thermal energy storage unit and stored by the thermal energy storage unit. E.g. ordered electric energy, e.g. form an electric energy exchange, which is not needed by the methane production unit can be stored by the thermal energy storage unit. Further, in case the power source is a power plant, it is possible to use excess electric energy of the power plant, which would otherwise be unusable, in particular if the power plant is not connected to a general electric grid and only build for the methanation facility. According to this variation, the overall efficiency is further increased.

[0025] The excess electric energy from the power source, in particular in case of the power plant, is advantageously storable in the thermal energy storage unit when the thermal energy storage unit comprises an energy converter, in particular an electric heater, which is configured to transform the excess electric energy from the power source into thermal energy of the thermal energy storage unit, in particular by heating the working fluid of the thermal energy storage unit. The thermal heater is e.g. a resistance heater, which is arranged in the working fluid and which heats the working fluid when electric current flows through the resistance heater thereby heating the working fluid and transforming the electric energy into thermal energy. The electric heater is a particular simple and reliable variation for transforming the electric current into thermal energy. P28902PC00 23 Oktober 2025

[0026] 6 / 30

[0027] In a preferred variation comprises the methane production unit further an electrolysis unit configured to generate hydrogen used in the methanation reactor, wherein ohmic thermal energy from the electrolysis unit is provided to and stored by the thermal energy storage unit. The electrolysis unit may comprise one or a plurality of electrolyzers, which are configured to produce hydrogen using water and electric energy from the power plant. The process of producing hydrogen by the electrolysis unit also produces thermal energy in particular ohmic thermal energy since it is released during the usage of electric energy, which is provided to and stored by the thermal energy storage unit as thermal energy, which is afterwards further provided to and used by the methane production unit. By using additionally the ohmic thermal energy it is further possible to increase the overall efficiency of the methanation facility. The ohmic thermal energy provide more energy compared to the reaction thermal energy but on a lower temperature level. Nevertheless, both types of energy, the ohmic thermal energy and the reaction thermal energy help to further increase the overall efficiency of the system.

[0028] An advantageous and efficient use of the stored thermal energy from the thermal energy storage unit is realizable when the stored thermal energy is used for preheating input fluid streams of the methane production unit. The input fluid streams include the water stream as input for the electrolysis unit and I or the hydrogen stream and I or the carbon oxide input stream, in particular carbon dioxide and I or carbon monoxide, as input for the methanation reactor. All of the different input stream are preferably temperature regulated such that the respective process or reaction is executable as effective and efficient as possible. It is therefore crucial to control the temperature of the input fluid streams respectively. This increases the overall efficiency and the yield of the methanation facility. Further, by using the thermal energy stored in the thermal energy storage unit for the temperature regulation of the input fluid streams the efficiency and the yield of the entire methanation facility is advantageously increased. P28902PC00 23 Oktober 2025

[0029] 7 / 30

[0030] It is further preferred that the methanation facility comprises at least one thermal heat consuming facility, which is thermally connected to the thermal energy storage unit, wherein the thermal energy storage unit is configured to provide thermal energy not required by the methane production unit to the thermal heat consuming facility. The thermal heat consuming facility is for example a consumer of heat or a heat sink forming part of the methanation facility. The methanation reaction and I or the electrolysis may provide further e.g. in combination with excess electric energy from the power plant more thermal energy as required by the methane production unit during its operation. At some point in time, the storing capacity of the thermal energy storage unit may be reached which could result in that further thermal energy could no longer be stored and used. By providing the thermal heat consuming facility, in particular a thermal connection of the thermal heat consuming facility to the thermal energy storage unit it is further possible to use the thermal energy not required by the methane production unit. The thermal heat consuming facility may also be a heat exchanger, which is connected to a heat sink arranged outside of the methanation facility e.g. a public or private swimming pool, spa, a public heat network or anything else, which requires thermal heat. The respective heat exchanger may form part of the methanation facility, the public or private swimming pool may not.

[0031] A particular advantageous transfer of thermal energy is realizable when a heat exchanger is arranged between the thermal heat consuming facility and the thermal energy storage unit, which thermally connect at least one cooling circuit of the thermal heat consuming facility with the at least one thermal circuit of the thermal energy storage unit. The heat exchanger enables the thermal energy transfer and at the same time to keep the respective thermal circuits separated. For example, it is thereby possible that different working fluids exchange thermal energy with each other.

[0032] In a further variation, the methanation facility comprises an electric energy storage unit, which is electrically connected to the power source and to the methane production unit, P28902PC00 23 Oktober 2025

[0033] 8 / 30 in particular the electrolysis unit, and which is configured to buffer electrical energy from the power source. The electric energy storage unit or battery unit is electrically connected to the power source for receiving electric energy from the power source and to the methane producing unit for providing the stored electric energy to the methane production unit. The electric energy storage unit may further be electrically connected to the thermal energy storage unit, in particular its electric heater, to also provide electric energy to the thermal energy storage unit, for transforming it and storing it as thermal energy. The electric energy storage unit enables that peak loads from the power source are buffered and further enables to store electric energy for using it directly by the methane production unit or indirectly via the thermal energy storage unit. The electric energy storage unit makes the entire methanation facility more versatile and more efficient.

[0034] In a further preferred variation, the methanation facility comprises a biogas plant, which is configured to produce and provide carbon oxide as input for the methanation reactor. Carbon oxide, monoxide or dioxide, is a waste product of the biogas plant, which can be advantageously used in the methanation reactor, thereby increasing the overall efficiency. Further, the thermal excess heat from the thermal energy storage unit may be provided to the biogas plant. The biogas plant is in this variation the thermal heat consuming facility, which uses the thermal excess energy for its operation, e.g. for drying biological material. In addition, a product or byproduct of the biogas plant could be bioethanol, which could also be used as a source of carbon oxide for the methanation reactor.

[0035] In a further preferred variation, the methanation facility comprises a direct carbon oxide capture plant, which is configured to produce and provide carbon oxide, in particular carbon monoxide and I or dioxide as input for the methanation reactor and I or wherein the stored thermal energy from the thermal energy storage unit is provided to the direct P28902PC00 23 Oktober 2025

[0036] 9 / 30 carbon oxide capture plant for its operation, thereby functioning as the thermal heat consuming facility. Further, the direct carbon oxide capture plant may be connected to the electric energy storage unit or to the power source and configured to use stored electrical energy from the electric energy storage unit or directly from the power source for its operation. The direct carbon oxide capture plant advantageously provides the required carbon oxide for the methane production.

[0037] It is further preferred that the power source is a power plant, which is configured to generate the electric energy, which is at least partially used directly by the methane production unit during its operation. The excess electric energy may be provided to the thermal energy storage unit. In a further embodiment, the power plant comprises at least one renewable power plant, in particular a photovoltaic power plant, a wind power plant, a hydroelectric power plant, nuclear power plant and / or a biogas power plant. The desired green methane is only produceable when using renewable energy for the operation of the methane production unit. Further, renewable power plants provide a more fluctuating electric current. The methanation facility as described above and hereinafter advantageously enable to handle and use the fluctuating electric current as efficient as possible.

[0038] The power plant may be located at the same site as the methane production unit or within electric energy transfer distance. In other words, the power plant may also be arranged relative far away, but its electric energy is at least partially used by the methane production unit. The electric energy is respectively transmitted to the methane production unit.

[0039] An advantageous thermal energy storage and transportation is realizable when the thermal energy storage unit comprises and uses as the thermal working fluid water, oil, ammoniac, alcohol or potassium hydroxide or a mixture thereof. It may also be conceivable that the thermal energy storage unit uses in different thermal circuits different working fluids. P28902PC00 23 Oktober 2025

[0040] 10 / 30

[0041] It is further preferred that a heat exchanger is arranged between the methanation reactor and the thermal energy storage unit, which thermally connects at least one cooling circuit of the methanation reactor with the thermal circuit of the thermal energy storage unit. It is thereby possible to thermally connect and fluidically separate the cooling circuit of the methanation reactor using e.g. cooling oil to I with the thermal circuit of the thermal energy storage unit using e.g. water as its working fluid.

[0042] It is further preferred that a heat exchanger is arranged between the electrolysis unit and the thermal energy storage unit, which thermally connects at least one cooling circuit of the electrolysis unit with the thermal circuit of the thermal energy storage unit. It is thereby possible to thermally connect and fluidically separate the cooling circuit of the electrolysis unit using e.g. a potassium hydroxide mixture as working fluid to I with the thermal circuit of the thermal energy storage unit using e.g. water as its working fluid.

[0043] It is in particular preferred that the thermal energy storage unit is further configured to provide stored thermal energy to the methane production unit, in particular to the methanation reactor, during its ramp up-process. The ramp up process or initiating process is the process of the methane production unit, during which the operation of the respective components of the methane production unit is initiated or started. The ramp up process of the methane production unit requires more thermal energy, e.g. for preheating the methanation reactor or for preheating the input fluid streams, compared to the standard operation of the methane production unit. Further, the usage of renewable energy, which is not available as reliable as conventional energy for the production of methane may require that the methane production unit needs to be stopped and restarted more often compared to methane production units, which only use conventionally produced electric power. Using the stored thermal energy in the thermal energy storage unit for the ramp-up process helps to further increase the efficiency of the entire methanation facility. P28902PC00 23 Oktober 2025

[0044] 11 / 30

[0045] According to a further aspect of the present disclosure, a method for operating a methanation facility for producing methane is specified. The method comprises a plurality of steps as described below. The sequence of the steps may vary.

[0046] In a first step, a methanation facility as described above and hereinafter is provided. The methanation facility may comprise all of the features described above and hereinafter, with the respective functionality.

[0047] A second step comprises to provide, by the power source, in particular the power plant, electric energy, which is at least partially used by the methane production unit for its operation.

[0048] A third step comprises to produce, by the methanation reactor methane and I or methanol by an exothermic reaction, thereby releasing reaction thermal energy.

[0049] A fourth step comprises to transfer and store the reaction thermal energy from the methanation reactor in the thermal energy storage unit of the methanation facility.

[0050] A fifth step comprises to provide the stored thermal energy back to the methane production unit for its operation and or to a heat consuming facility like a biogas plant.

[0051] The method may further comprise additional steps in particular as described above and hereinafter with respect to the methanation facility.

[0052] Each feature and any respective advantage disclosed and described with respect to the methanation facility for producing methane is also applicable mutatis mutandis to the above disclosed aspect of the method of operating the methanation facility. In particular each feature disclosed and described with respect to the methanation facility may be used to limit the method of operating the methanation facility and vice versa. P28902PC00 23 Oktober 2025

[0053] 12 / 30

[0054] It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings, which should not be considered limiting to the disclosure described in the appended claims. The drawings are showing:

[0057] Fig. 1 a schematic view of a methanation of methane and I or methanol using a methane production unit;

[0058] Fig. 2 a schematic representation of a methanation facility; Fig. 3 a schematic representation of a methanation facility according to Figure 2 with a more detailed representation of its components:

[0059] Fig. 4 shows a flow diagram illustrating schematically a plurality of steps of a method of operating a methanation facility as shown e.g. in the Figures 2 and 3. P28902PC00 23 Oktober 2025

[0060] 13 / 30

[0061] DESCRIPTION OF THE EMBODIMENTS

[0062] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0063] Figure 1 shows a schematic view of a methanation of methane and I or methanol using a methane production unit 1. Figure 1 focuses on the fluid and energy input 2 and output streams 7, which are required to produce the desired methane and I or methanol. The methane production unit 1 comprises at least one electrolyser20 and at least one reactor 25. The electrolyser 20 is configured to produce hydrogen 6 and oxygen 10 using water 5 and electric energy 3, and the reactor 25 is configured to produce methane 8 and I or methanol using the produced hydrogen 6, carbon oxide 4 (dioxide and / or monoxide) and electric energy 3. The electric energy 3, the water 5 and the carbon oxide 4 are the input fluid streams 2. In another embodiment, the hydrogen 6 is not produced by the methane production unit 1 itself, but may be supplied directly to the methane production unit 1. In this case also the hydrogen 6 would form an input fluid stream 2 into the methane production unit 1 and not only between the electrolyser 20 and the reactor 25. The methane production unit 1 is configured to perform the electrolysis of water 5 using one or more electrolysers 20 to disperse water 5 into hydrogen 6 and oxygen 10. At least the hydrogen 6 is further used in the reactor 25 of the methane production unit 1. The reactor 25 is configured to produce methane 8 and I or methanol using the produced hydrogen 6, supplied carbon oxide 4 and electric energy 3. A side product of the reactor 25 is waste water 9. The waste water 9 may be reused as input water 5 for the methane production unit 1. A further side product of the at least one electrolysers 20 is the oxygen 20. The P28902PC00 23 Oktober 2025

[0064] 14 / 30 methane 8 and I or methanol, the waste water 9 and the oxygen 10 are output variables 7 of the methanation plant 1.

[0065] Figure 1 shows the methane production unit 1 in a super simplified manner, nevertheless, the most relevant fluid streams 2 and the resulting output fluid streams 7 are advantageously shown in Figure 1.

[0066] Figure 2 shows a methanation facility 100, comprising the methane production unit 1 and further components. Figure 2 advantageously the methanation facility 100 comprising a power source 109, in particular a power plant 110, configured to generate electric energy 3, which is at least partially used by the methane production unit 1 during its operation. The methane production unit 1 of Figure 2 comprises a methanation reactor 25 configured to produce the methane and I or the methanol by an exothermic reaction, thereby releasing reaction thermal energy 150. The methane production unit 1 further comprises an electrolysis unit 18 comprising all of the electrolyzers 20 (shown in Figure 3). The electrolysis unit 18 is configured to generate hydrogen 6 used in the methanation reactor 25, wherein ohmic thermal energy 154 is released by the electrolysis unit 18 during its operation. The reactor 25 may comprise a plurality of reactors 25 arranged in series. The reactor 25 is further connected to a methane grid 32, which receives the produced methane 8 and transports the methane 8 to the consumers.

[0067] The power plant 110, as power source 109, is electrically connected to the methane production unit 1 via a respective electric connection 160. The power plant 110 is preferably a renewable power plant 110, producing renewable electric energy 3. The power plant 110 may be a photovoltaic power plant 111 , a wind power plant 112, biogas power plant 113 and / or a hydroelectric power plant 114. A plurality of power plants 110 are also conceivable. Figure 2 further shows a thermal energy storage unit 120, which comprises a thermal circuit 121 using a working fluid 122. The thermal energy storage unit P28902PC00 23 Oktober 2025

[0068] 15 / 30

[0069] 120 is further configured for receiving and storing the reaction thermal energy 150 from the methanation reactor 25 and I or the ohmic thermal energy 154 from the electrolysis unit 18. The thermal energy storage unit 120 is further configured to provide the stored thermal energy 152 back to the methane production unit 1 during its operation. The working fluid 122 used in the thermal circuit 121 of the thermal energy storage unit 120 comprises e.g. water, oil, ammoniac alcohol. A combination of these working fluids is also conceivable. Figure 2 further shows that the power plant 110 is also electrically connected to the thermal energy storage unit 120. The thermal energy storage unit 120 is further configured for receiving and storing excess electric energy 3 from the power plant 110, via the respective electric connection 160 or the power source 109, which is not directly used by the methane production unit 1. The thermal energy storage unit 120 comprises an energy converter, in particular an electric heater 124, which is configured to transform the excess electric energy 3 from the power plant 110 into thermal energy 152 of the thermal energy storage unit 120 by heating the thermal working fluid 122 of the thermal energy storage unit 120. The electric heater 124 is for example an immersion heater, which is arranged in the thermal working fluid 122 of the thermal circuit 121 of the thermal energy storage unit.

[0070] Figure 2 further shows a plurality of thermal heat consuming facilities 130, in particular two thermal heat consuming facilities 130. The first one shown one shown on the right side of figure 2 is for example a public facility like a swimming pool of a connection to a district heating grid. The sored thermal energy 152 may be provided to the thermal heat consuming facilities 130. The second thermal heat consuming facility 130 is in this embodiment a biogas plant 134 or a direct carbon oxide capture plant 135, in particular a biogas power plant 113. The biogas plant 134, which is configured to produce and provide carbon oxide 4 (monoxide and I or dioxide) as input for the methanation reactor 25 and I or wherein the stored thermal energy 152 from the thermal energy storage unit 120 is provided to the biogas plant 134 for its operation. The biogas plant 134 could further P28902PC00 23 Oktober 2025

[0071] 16 / 30 produce bioethanol as a product or byproduct, which could also be a source of carbon oxide for the methanation reactor 25. The thermal energy 152 from the thermal energy storage unit 120 is e.g. used for drying biodegradable material. Further, in case of the biogas power plant 113, produced electric energy 3 may also be provided to the methane production unit 1 for its operation. It is further visible in Figure 2 that respective heat exchangers 132 are arranged between the thermal heat consuming facilities 130 and the thermal energy storage unit 120, which thermally connect at least one thermal circuit of the respective thermal heat consuming facility 130 with the thermal circuit 121 of the thermal energy storage unit 121. Thermal energy transfer is enabled but the respective working fluids can be kept separated. In case of the direct carbon oxide capture plant 134, the produced carbon oxide 4 is provided to the methane production unit 1 and thermal energy 152 and or excess electric energy 3 may be provided to the direct carbon oxide capture plant 134 for its operation.

[0072] Figure 2 further shows a respective heat exchanger 142 between the reactor 25 and the thermal energy storage unit 120 and a respective heat exchanger 144 between the electrolysis unit 18 and the thermal energy storage unit 120. The thermal circuit of the reactor 25 may use as working fluid a cooling oil and the thermal circuit of the electrolysis unit 18 may us as working fluid potassium hydroxide. The working fluid 122 of the thermal energy storage unit 120 is e.g. water. The respective heat exchanger 142 and 144 enable the required energy transfer but keep the working fluids separate at the same time.

[0073] Figure 2 further shows an additional heat exchanger 146, which is arranged upstream of the electrolysis unit 18 and which is configured to control the temperature of the input fluid streams 2 into the electrolysis unit 18. Similarly such a heat exchanger 146 may also be arranged downstream of the electrolysis unit 18 and upstream of the reactor 25. In this case, not shown in the Figures, the temperatures of the input fluid streams 2 into the reactor 25 may be controlled respectively. P28902PC00 23 Oktober 2025

[0074] 17 / 30

[0075] Figure 2 further shows an electric energy storage unit 140 or battery, which is electrically connected via respective electric connections 160 to the power plant 110, the methane production unit 1 , in particular to the electrolysis unit 18 and the thermal energy storage unit 120, in particular the electric heater 124. The electric energy storage unit 140 is configured to receive and store electrical energy from the power plant 110 and to provide the stored electric energy to the methane production unit 1 and I or to the thermal energy storage unit 120. In case the electric energy 3 generated by the power plant 110 is larger as required for the operation of the methane production unit 1 , the excess electric energy 3 from the power plant 110, may be stored in the electric energy storage unit 140 and I or in the thermal energy storage unit 120. E.g. the excess electric energy 3 is stored in the electric energy storage unit 140 till it is full. Afterwards, the excess electric energy 3 is stored in the thermal energy storage unit 120.

[0076] Figure 3 shows the methanation facility 100 comprising the methane production unit 1 and the further components also described e.g. in Figure 2 schematically in a more detailed manner. The methane production unit 1 comprises six electrolysers 20 in its electrolysis unit 18, which are configured to produce the required hydrogen 6. More or less electrolysers 20, e.g. three each having a capacity of 3 MW is also conceivable. Each of the electrolysers 20 is supplied with electric energy 3 and water 5. The water 5 may be waste water 9 from the facility 100 itself or fresh water or water from a biogas plant 134 or a mixture thereof. The methane production unit 1 further comprises according to this embodiment a CO2 and I or CO tank 21 , which is configured to provide carbon oxide 4 to the methane production unit 1. Further, the biogas plant 134 may also provide the required carbon oxide 4. In another embodiment the methane production unit 1 may have access to carbon oxide 4 via respective carbon dioxide grid or a CO2 tank 21 outside of the methane production unit 1. The carbon oxide 4 used is preferably biogenic carbon oxide 4. In another embodiment, the methane production unit 1 may produce its own carbon oxide 4. The methane production unit 1 further comprises a gas mixer 22, which P28902PC00 23 Oktober 2025

[0077] 18 / 30 is configured to collect and mix the hydrogen 6 produced from the electrolysers 20 and the carbon oxide 4 from the CO2 CO tank 21 and of from the biogas plant 134. In other words, the gas mixer 22 forms the desired gas composition using at least the hydrogen 6 and the carbon oxide 4. The methane production unit 1 further comprises a compressor 23, which is configured to set the gas pressure of the hydrogen and carbon oxide mixture as desired. In another embodiment, the compressor 23 may be arranged upstream of the gas mixer 22 and is configured to compress only the hydrogen 6. Another compressor may compress the carbon oxide 4. The compressor 23 is supplied with electric energy 3 for its operation. The methane production unit 1 further comprises a heater or heat exchanger 24, which is configured to set the gas mixture temperature as desired e.g. by heating or by cooling of the gas mixture. The compressor 23 and the heater 24 are configured to set the properties of the gas mixture such as desired for the methanation. The heat exchanger 24 may also be at least partially supplied with stored thermal energy 152 from the thermal energy storage unit 120 or may provide excess thermal energy to the thermal energy storage unit 120 as indicated in Figure 3. The methane production unit 1 further comprises two reactors 25 arranged in series, which are configured to receive the gas mixture and to synthesize methane 8 out of the supplied carbon oxide 4 and hydrogen 6. In other variations, only one or a plurality of reactors 25 may be used, which are arranged parallel or in series with each other. Using a plurality of reactors 25 in series may increase the product yield.

[0078] The synthesis of methane 8 (methanation) from CO2 (as well as CO) is a strongly exothermic reaction that requires efficient heat removal from the reaction zone, particularly when carried out catalytically with short reaction times. Conventionally, random fixed- bed reactors are used. Catalyst pellets may be arranged randomly unstructured and may move freely. An alternative to the random fixed-bed reactors are structured fixed-bed reactors with a plurality of channels, which comprise a catalyst coating. These reactors comprise a solid body structure, which define the channels. The reactants stream P28902PC00 23 Oktober 2025

[0079] 19 / 30 through the channels and react in the channels with the catalyst coating. The reaction zone is therefore within the channels. For example, the document DE 10 2016 125 641 A1 discloses a process for production of a natural gas substitute from hydrogen-contain- ing gas mixtures using a reactor with channels.

[0080] Regardless of the reactor type employed, the strongly exothermic nature of methane synthesis requires careful control of the heat removal from the reaction zone for controlling the temperature inside the reactor zone. Heat removal of the reaction zone is particularly critical and challenging for structured fixed-bed catalysts. The methane production unit 1 comprises therefore a coolant circuit 26 for controlling of the temperature inside of at least one of the reactors 25, in the embodiment of figure 3 of the upstream arranged reactor 25, which is important for ensuring a high quality and high purity product and for ensuring high yields of the target product. In particular, the chemical equilibrium of the different chemical reactions taking place is temperature dependent. Typically, it is desirable to maintain the temperature within a narrow target temperature range, in which the balance between high product yield, high product purity and a fast reaction is advantageous. The coolant circuit 26 comprises a coolant heater 27 and a coolant pump 28. The coolant heater 27 is configured to set the temperature of the coolant and the coolant pump 28 is configured to set the flow rate of the coolant. The coolant used are e.g. coolant oils, water etc. The coolant circuit 26, in particular its components are supplied with electric energy 3 for the desired operation.

[0081] The methane production unit 1 further comprises a water separator 29 arranged downstream of the reactor 25 which is configured to separate the water 9 out of the product gas of the reactor 25. The separated wastewater 9 may be reused by the methane production unit 1 itself. The water separator 29 may also be supplied with electric energy 3 for its operation. The methane production unit 1 further may comprise additional post processing components 30 like heaters filters etc. These components may also need P28902PC00 23 Oktober 2025

[0082] 20 / 30 electric energy 3 for their operation. The methane production unit 1 additionally comprises downstream of the separator 29 a compressor 31 , which is configured to set the pressure of the resulting methane 8 or green natural gas. The compressor 31 may additionally require for its operation electric energy 3. The resulting green natural gas 8 is supplied with the desired high purity quality and pressure to a gas grid 32, which is configured to transport the methane 8 to customers. In other embodiments, the produced methane 8 may be directly supplied to a single or more customers.

[0083] Figure 3 further indicates a control unit 40, which is configured to control the methanation facility 100, in particular all of the described components such that the components work together as desired for producing the methane 8 using the available input fluid streams 2. Figure 2 further indicates exemplary a sensor 33, which is configured to provide a sensor signal 34 to the control unit 40 indicative of a parameter of a component of the methane production unit 1 . A plurality of sensors 33 in particular for each of the different components is also conceivable.

[0084] Figure 3 further shows the additional components of the methanation facility 100 not forming part of the methane production unit 1 as also explained with respect to Figure 2. Figure 3 also shows as the power source 109 the power plant 110 configured to generate the electric energy 3 used at least partially directly by the methane production unit 1 , in particular by the different components described above during their operation. Figure 3 indicates that the power plant 110 might be a photovoltaic power plant 111 , a wind power plantl 12 a biogas power plant 113 or a hydroelectric power plant 114 a combination would also be conceivable. Figure 3 further shows the electric energy storage unit 140 electrically connected to the methane production unit 1 , the power plant 110 and the thermal energy storage unit 120. The electric energy storage unit 140 is configured to receive excess electric energy 3 from the power plant 110, which is not required by the P28902PC00 23 Oktober 2025

[0085] 21 / 30 methane production unit 1. Furthermore, the electric energy storage unit 140 might also be configured to transfer stored electric energy 3 to the thermal energy storage unit 120.

[0086] The thermal energy storage unit 120 comprises the thermal circuit 121 using e.g. water as the thermal working fluid 122. The thermal energy storage unit 120 further comprises an electric heater 124, which is configured to transform the received electric energy 3 from the power plant 110 or the electric energy storage unit 140 into thermal energy 152. The thermal energy storage unit 120 may further com prise a reservoir or tank in particular insulated tank for storing the thermal working fluid.

[0087] Figure 3 further shows the thermal heat consuming facilities 130, which are thermally connected to the thermal energy storage unit 120. One of the thermal heat consuming facilities 130 is e.g. the direct carbon oxide capture plant 134 and I or the biogas plant 134, which uses the thermal heat 152 for drying the biological material used for its operation, and which provides the carbon oxide 4 to the methane production unit 1. Further, the biogas plant 134 may also produce electric energy 3, which is also provided to the methane production unit 1. In this case, the biogas plant 134 is a biogas power plant 113. The other thermal heat consuming facility 130 may be a public swimming pool outside of the methanation facility 100. Figure 3 further shows the heat exchangers 132 arranged between the thermal heat consuming facilities 132 and the thermal energy storage unit 120, which thermally connect both with each other and at the same time keep the respective thermal working fluid circuits fluidically separated.

[0088] Figure 3 further shows the thermal connections of the thermal energy storage unit 120 to the electrolysis unit 18, the input fluid streams 2 into the reactor 25 and to the cooling circuit 26 of the reactor 25. These thermal connections are arranged and configured such that the reaction thermal energy 150 from the methanation reactor 25 and the ohmic thermal energy 154 from the electrolysis unit 18 is transmittable to the thermal energy P28902PC00 23 Oktober 2025

[0089] 22 / 30 storage unit 120, in particular via respect heat exchangers 142, 144. Furthermore, the thermal connections enable that thermal energy 152 from the thermal energy storage unit 120 can be transferred to methane production unit 1 , in particular for heating the input fluid streams 2 into the electrolysis unit 18 and I or the methanation reactors 25.

[0090] The control unit 40 is according to this embodiment configured to control the operation of the entire methanation facility 100, in particular of the methane production unit 1 , thermal energy storage unit 120, the power plant 110, the thermal heat consuming facilities 130 and the electric energy storage unit 140.

[0091] Figure 4 shows a flow diagram illustrating schematically a plurality of steps for operating the methanation facility 100 as illustrated with respect to Figure 3. The methanation facility 100 is e.g. controlled by the control unit 40 respectively. In the following paragraphs, described with reference to Figure 4 is a possible sequence of steps for operating the methanation facility 100.

[0092] In step SO, the methanation facility 100 as described above and hereinafter is provided. In other words, the methanation facility 100 as described above and hereinafter is used to produce methane 8 and I or methanol.

[0093] In step S1 , the power plant 110 generates electric energy 3, which is used by the methane production unit 1 of the methanation facility 100 for its operation.

[0094] In step S2, the methanation reactor 25 produces methane 8 and I or methanol by an exothermic reaction, thereby releasing reaction thermal energy 150.

[0095] In step S3, the reaction thermal energy 150 from the methanation reactor 25 is transferred to and stored by the thermal energy storage unit 120. P28902PC00 23 Oktober 2025

[0096] 23 / 30

[0097] In step S4, the stored thermal energy 152 from the thermal energy storage unit 120 is provided back to the methane production unit 1 for its operation.

[0098] The method may further comprise additional steps in particular as described above and hereinafter with respect to the methanation facility.

[0099] P28902PC00 23 Oktober 2025

[0100] 24 / 30

[0101] LIST OF DESIGNATIONS

[0102] 1 Methane production unit 30 109 power source

[0103] 2 Input fluid streams 110 power plant

[0104] 3 Electric energy 111 photovoltaic power plant

[0105] 4 Carbon oxide (CO, CO2) 112 wind power plant

[0106] 5 Water 113 biogas power plant

[0107] 6 Hydrogen (H2) 35 114 hydroelectric power plant

[0108] 7 Output fluid streams 120 thermal energy storage unit

[0109] 8 Methane CH4 121 thermal circuit

[0110] 9 waste water 122 thermal working fluid

[0111] 10 Oxygen 124 electric heater

[0112] 18 Electrolysis unit 40 130 thermal heat consuming facility

[0113] 20 Electrolyzer 132 heat exchanger

[0114] 21 CO2 Tank 134 biogas plant

[0115] 22 Gas mixer 135 direct carbon oxide capture plant

[0116] 23 Compressor 140 electric energy storage unit

[0117] 24 Heater I heat exchanger 45 142 heat exchanger

[0118] 25 Methane reactor 144 heat exchanger

[0119] 26 Coolant circuit 146 heat exchanger

[0120] 27 Coolant heater 150 reaction thermal energy

[0121] 28 Coolant pump 152 stored thermal energy

[0122] 29 H2O Separator 50 154 ohmic thermal energy

[0123] 30 Post processing (heater etc.) 160 electric connection

[0124] 31 Compressor 50 Providing

[0125] 32 Methane grid 51 Generating

[0126] 33 Sensor 52 Producing

[0127] 34 Sensor signal 55 S3 Transferring and Storing

[0128] 40 Control unit S4 Providing

[0129] 100 Methanation facility

Claims

P28902PC00 23 Oktober 202525 / 30PATENT CLAIMS1. A methanation facility (100) for producing methane (8) and I or methanol, the methanation facility (100) comprises: a. a methane production unit (1) comprising: i. a methanation reactor (25) configured to produce the methane (8) and I or the methanol by an exothermic reaction, thereby releasing reaction thermal energy (150); b. a power source (109) configured to provide electric energy (3), which is at least partially used directly by the methane production unit (1) during its operation; c. a thermal energy storage unit (120), which comprises a thermal circuit (121) using a thermal working fluid (122), and which is configured for receiving and storing the reaction thermal energy (150) from the methanation reactor (25), wherein the thermal energy storage unit (120) is further configured to provide stored thermal energy (152) back to the methane production unit (1) during its operation.

2. The methanation facility (100) according to claim 1 , wherein the thermal energy storage unit (120) is further configured for receiving and storing excess electric energy (3) from the power source (109), which is not directly used by the methane production unit (1).P28902PC00 23 Oktober 202526 / 303. The methanation facility (100) according to claim 2, wherein the thermal energy storage unit (120) comprises an energy converter, in particular an electric heater (124), which is configured to transform the excess electric energy (3) from the power source (109) into thermal energy (152) of the thermal energy storage unit (120) by heating the thermal working fluid (122) of the thermal energy storage unit (120).

4. The methanation facility (100) according to any one of the preceding claims, wherein the methane production unit (1) further comprises: i. an electrolysis unit (18) configured to generate hydrogen (6) used in the methanation reactor (25), wherein ohmic thermal energy (154) released by the electrolysis unit (18) during its operation is provided to and stored by the thermal energy storage unit (120).

5. The methanation facility (100) according to any one of the preceding claims, wherein the stored thermal energy (152) from the thermal energy storage unit (120) is used for preheating input fluid streams (2) of the methane production unit (1), in particular of the methanation reactor (25) and I or of the electrolysis unit (18).

6. The methanation facility (100) according to any one of the preceding claims, further comprising: a. at least one thermal heat consuming facility (130), which is thermally connected to the thermal energy storage unit (120), wherein the thermal energy storage unit (120) is configured to provide the stored thermal energy (152) not required by the methane production unit (1) for its operation to the thermal heat consuming facility (130).P28902PC00 23 Oktober 202527 / 307. The methanation facility (100) according to claim 6, wherein a heat exchanger (132) is arranged between the thermal heat consuming facility (130) and the thermal energy storage unit (120), which thermally connect at least one thermal circuit of the thermal heat consuming facility (130) with the thermal circuit (121) of the thermal energy storage unit (121).

8. The methanation facility (100) according to any one of the preceding claims, further comprising: a. an electric energy storage unit (140), which is electrically connected to the power source (109) and to the methane production unit (1), in particular to the electrolysis unit (18), and I or to the thermal energy storage unit (120), wherein the electric energy storage unit (140) is configured to receive and store electrical energy from the power source (109) and to provide the stored electric energy to the methane production unit (1) and I or to the thermal energy storage unit (120).

9. The methanation facility (100) according to any one of the preceding claims, further comprising: a. a biogas plant (134), which is configured to produce and provide carbon oxide (4) as input for the methanation reactor (25) and I or wherein the stored thermal energy (152) from the thermal energy storage unit (120) is provided to the biogas plant (134) for its operation, thereby functioning as the thermal heat consuming facility (130), and I or b. a direct carbon oxide capture plant (135), which is configured to produce and provide carbon oxide (4) as input for the methanation reactor (25) and / or wherein the stored thermal energy (152) from the thermal energyP28902PC00 23 Oktober 202528 / 30 storage unit (120) is provided to the direct carbon oxide capture plant (135) for its operation, thereby functioning as the thermal heat consuming facility (130), and I or the stored electrical energy from the electric energy storage unit (140) is provided to the direct carbon oxide capture plant (135) for its operation.

10. The methanation facility (100) according to any one of the preceding claims, wherein the power source (109) is a power plant (110), which is configured to generate the electric energy (3), which is at least partially used directly by the methane production unit (1) during its operation, the power plant (110) is preferably a a renewable power plant, in particular at least one of: a photovoltaic power plant (111), a wind power plant (112), biogas power plant (113) or a hydroelectric power plant (114).

11. The methanation facility (100) according to any one of the preceding claims, wherein the thermal energy storage unit (120) comprises and uses as the thermal working fluid (122) at least one of: water, oil, ammoniac or alcohol.

12. The methanation facility (100) according to any one of the preceding claims, wherein a heat exchanger (142) is arranged between the methanation reactor (25) and the thermal energy storage unit (120), which thermally connects at least one cooling circuit of the methanation reactor (25) with the thermal circuit (121) of the thermal energy storage unit (120).

13. The methanation facility (100) according to any one of the claims 2 to 11 , wherein a heat exchanger (144) is arranged between the electrolysis unit (18) and the thermal energy storage unit (120), which thermally connects at least one cooling circuitP28902PC00 23 Oktober 202529 / 30 of the electrolysis unit (18) with the thermal circuit (121) of the thermal energy storage unit (120).

14. The methanation facility (100) according to any one of the preceding claims, wherein the thermal energy storage unit (120) is further configured to provide stored thermal energy (152) to the methane production unit (1), in particular to the methanation reactor (25), during its ramp up-process.

15. A method for operating a methanation facility for producing methane (8) and I or methanol: a. Providing (SO) a methanation facility (100) according to any one of the preceding claims; b. Providing (S1), by the power source (109) electric energy (3), which is used by the methane production unit (1) for its operation; c. Producing (S2), by the methanation reactor (25) methane (8) and I or methanol by an exothermic reaction, thereby releasing reaction thermal energy (150); d. Transferring and storing (S3) the reaction thermal energy (150) from the methanation reactor (25) in the thermal energy storage unit (120); e. Providing (S4) the stored thermal energy (152) from the thermal energy storage unit (120) back to the methane production unit (1) for its operation.

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