Methanation with turbocharger

Abstract

This invention relates to an improved methanation process, wherein the energy released during the methanation process is used to drive a turbocharger to drive and / or sustain the process. The invention also relates to a system for producing methane-rich gas and power from hydrogen and carbonaceous feedstock, the system comprising at least one methanation reactor and at least one turbocharger.

Description

Technical Field

[0001] This invention relates to an improved methanation process, wherein energy released during the methanation process is used to drive a turbocharger to drive and / or sustain the process. The invention also relates to a system for producing methane-rich gas and optional power from hydrogen and carbonaceous feedstock, the system comprising at least one methanation reactor and at least one turbocharger. Background Technology

[0002] Methanation refers to the conversion of carbon monoxide (CO) and / or carbon dioxide (CO2) into methane (CH4) via hydrogenation. This process was discovered in the early 20th century. The following exemplary reactions illustrate the methanation of carbon monoxide and carbon dioxide, respectively:

[0003] CO + 3H₂ → CH₄ + H₂O

[0004] 4H2 + CO2 → CH4 + 2H2O

[0005] Methanation is an exothermic reaction.

[0006] Examples of possible starting materials are CO2 from biogas treatment plants and H2 from high-temperature electrolysis plants. Examples of prior art methanation processes include those from Haldor. The Topsoe Cycle Energy-Saving Methanation Process (TREMP) TM Due to the TREMP TM The process utilizes the MCR-2X methanation catalyst, which can operate at temperatures up to 937 K. This MCR-2X catalyst allows for heat recovery of the reaction in the form of high-pressure superheated steam and a low recycle ratio, ensuring energy savings. CO methanation takes place in a fixed-bed adiabatic reactor. The exothermic reaction causes the temperature to rise to a relatively high level. The reaction products (methane-rich gas) produced in this process are partially recycled to control the temperature rise in the methanation reactor. Over the past decade, interest in alternatives to natural gas has intensified, and technological efforts have been restarted, with knowledge gained over the years being used to improve tested and proven technologies and catalysts. A demonstration plant (Westfield Gasification Plant) has been built in Scotland, producing 2.46 million Nm³ of coal. 3 / h of SNG. The methanation unit used in this plant consists of a fixed-bed reactor with gas circulation.

[0007] A further development by British Gas is the HICOM process, in which methane-rich gas is directly produced from purified gasifier product gas by reacting it with steam over a catalyst; temperature rise is controlled through hot gas recirculation and splitting operations.

[0008] In Germany, Linde developed an isothermal fixed bed reactor with indirect heat exchange. The reactor itself is able to generate steam by the heat of the exothermic methanation reaction. Before feeding a part of the steam to the isothermal and adiabatic methanation reactor, this part of the steam is added to the syngas mixture to minimize the risk of carbon deposition.

[0009] All of the above processes use fixed bed reactors with recirculated cooled product gas and / or added steam. This is necessary in order to effectively dissipate the high reaction enthalpy (about 20% of the heating value of the feed gas) and, if necessary, to advantageously use it for the generation of steam and optionally superheated steam.

[0010] On the other hand, in smaller systems, a single-stage and almost isothermal reactor arrangement is usually used and is often used in combination with a heat power plant. The heat generated in the methanation process is used to heat a working medium located in the heat power plant. Usually, the working medium is water and by providing a boiling water reactor the reaction temperature in the methanation reactor is controlled. Alternative working media are hot oil and molten salt. The water is heated to generate steam. The steam is then expanded in a steam turbine to generate electricity.

[0011] CO / CO2 methanation has many practical applications. It is a process to export carbon oxides from process gases and it is also considered as an alternative to the preferential oxidation (PROX) of carbon monoxide in a gas mixture by a catalyst in a fuel processing system for mobile fuel cell applications. Since the 1970s, methanation has been considered as a method to produce synthetic natural gas. Recently, it has been considered as a way to store solar or wind generated energy using a power-to-gas system in combination with existing natural gas storage. The demand for seasonal energy storage can increase as part of the energy transition. If 80% of the electricity is generated with renewable energy, 30 TWh of storage capacity is expected to be needed in Germany.

[0012] The power-to-gas process is the most promising technology for seasonal energy storage, in which energy is stored by the synthesis of gases using excess electrical energy. The main storage media are hydrogen and methane. Methane has the advantage over hydrogen that existing infrastructure (natural gas pipelines and natural gas storage tanks) can be used. In 2018, there were 128 power-to-gas research and demonstration plants in Europe, which shows great interest in this technology.

[0013] For a methanation process to be economically and technically feasible, the resulting methane must meet several requirements. The methane produced during methanation needs to be of high purity, as insufficiently pure methane cannot be fed into the natural gas network. Furthermore, the methane must be pressurized before being fed into the natural gas network. Therefore, a satisfactory methanation process must produce high-purity, pressurized methane.

[0014] However, the possible sources of feedstock for the methanation process are biogas plants that provide CO2 and high-temperature electrolysis plants that provide H2. These plants typically produce low-pressure products. Therefore, some existing methanation plants operate at low pressure, resulting in lower methane purity. This methane needs to be purified and pressurized before being fed into the natural gas network.

[0015] Therefore, a process for producing pressurized methane by compressing feedstock has been developed. Methanation is typically carried out at elevated pressures to shift the equilibrium towards methane according to Le Chatelier's principle. Depending on the application, the target is typically a maximum residual hydrogen content of 2%–5%. For feed gases with low initial inlet pressures, electric compressors are usually used. To improve the equilibrium position, (partial) intermediate condensation of water vapor formed between the two methanation stages can also be provided. This shifts the equilibrium accordingly to the right side of the equation.

[0016] Pressurizing raw materials to obtain pressurized pure methane requires energy. In existing technologies, electric compressors that require external energy (e.g., electricity) are typically used to pressurize the raw materials. The cost associated with this part of the process accounts for 50% of the total system cost. Therefore, a process is needed that can minimize the costs associated with pressurizing the raw materials. To achieve this, energy needs to be used efficiently to make the process economically and technically feasible.

[0017] Therefore, there is a need for an improved methanation process and system that effectively utilizes the energy provided by the exothermic reaction, minimizes the need for external energy use, and thus efficiently provides sufficiently pure, pressurized, methane-rich gas for feed into natural gas pipelines. Summary of the Invention

[0018] This invention provides an improved methanation process and system that effectively utilizes the energy provided by the exothermic reaction, minimizing the need for external energy use, thereby efficiently providing pressurized methane-rich gas and even pure methane for feeding into natural gas pipelines or for other downstream applications.

[0019] This invention uses a turbocharger driven by the heat of reaction generated in a methanation reactor to pressurize the raw materials and / or methane-rich gas produced in the system, thereby significantly reducing the cost associated with using an electric compressor.

[0020] The improved methanation process and system of the present invention utilizes a novel combination of one or more methanation stages and one or more turbochargers, which may be supplemented by heat exchangers. The methanation process can be adiabatic in each stage. However, the methanation process can also be isothermal in one or more stages.

[0021] The improved methanation process and system of the present invention can be implemented in a variety of ways.

[0022] In one embodiment, the gas to be methanated (feed gas) or the methane-rich (methanated) gas (product gas) flows completely through both components of the turbocharger.

[0023] In another embodiment, the gas to be methanated or the methanated gas flows only through the compressor of the turbocharger.

[0024] In one embodiment of the invention, the methanation gas is not fed into the methanation reactor that produces the methanation gas. The methanation gas is transported downstream through a continuous gas pipeline and completely discharged from the system. In other words, all the generated methanation gas can be discharged at the outlet of the continuous gas pipeline. Discharging all the methanation gas from the system means that the methane-rich gas generated in the process will not be returned to one or more methanation reactors from the outlet of the continuous gas pipeline. Avoiding methanation gas recirculation simplifies the system structure and avoids the need for relatively expensive high-temperature compressors or intermediate cooling steps, as described in the prior art TREM process.

[0025] In another embodiment, a portion of the methane-rich gas can be recycled and fed into the methanation reactor to control the reaction temperature.

[0026] In another embodiment, a portion of the methane-rich gas can be recirculated via a simple control valve without the need for an additional recirculation compressor. This is likely because the turbocharger's compression of the main gas flow results in a higher pressure at the system outlet than at the inlet.

[0027] The main advantage of this invention is that an increased pressure is achieved at the system outlet compared to the initial pressure of the feedstock. The pressurized methane-rich gas can be used directly in downstream applications, such as being fed into a natural gas pipeline, without requiring further pressurization. Therefore, the process and system of this invention can use feedstock at low pressure (e.g., atmospheric pressure) while still providing pressurized methane-rich gas. Consequently, the process and system of this invention do not require feedstock at high pressure, and thus avoid, for example, the high process costs associated with using electrical energy for pressurizing feedstock in a compressor. Furthermore, with the process and system of this invention, further pressurization is not required before using the methane-rich gas in downstream processes. Therefore, the costs associated with this pressurization step are also avoided.

[0028] Therefore, the present invention provides an improved methanation process and system that can effectively utilize the energy provided by the exothermic reaction and minimize the need for external energy use, thereby effectively providing pressurized methane-rich gas, and even pure methane, for feeding into a natural gas pipeline network. Attached Figure Description

[0029] Figure 1 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a turbocharger 2 and an integrated adiabatic methanation reactor 1.

[0030] Figure 2 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a turbocharger, an integrated adiabatic methanation reactor, and a heat exchanger 8. The heat exchanger is a recuperator, wherein the produced methane-rich gas heats the hydrogen and carbonaceous raw materials leaving the compressor 3.

[0031] Figure 3 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a turbocharger, a methanation reactor 1 disposed downstream of the turbocharger, and a heat exchanger 8. The heat exchanger is a regenerator in which the produced methane-rich gas heats the hydrogen and carbonaceous raw materials leaving the compressor.

[0032] Figure 4 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a turbocharger and a methanation reactor 1 disposed upstream of the turbocharger. The system also includes two heat exchangers 8.

[0033] Figure 5 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to...Figure 4 The system shown. The heat flow 10 from the methanation reaction is used to recover the methane-rich gas produced before it enters the turbine.

[0034] Figure 6 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a turbocharger with countercurrent flow of the produced methane-rich gas, which enters the turbine before entering the compressor of the turbocharger.

[0035] Figure 7 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 1 The system also includes the injection of water 11, which is pressurized by pump 12 and preheated and / or partially or completely evaporated in preheating elements / evaporators 8c / 8d into the methanation reactor for temperature control and increasing mass flow rate.

[0036] Figure 8 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 7 The system comprises two methanation reactors. The first methanation reactor is an adiabatic methanation reactor; the second methanation reactor is an isothermal methanation reactor.

[0037] Figure 9 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes two methanation reactors. The first methanation reactor is cooled by a boiling water cooler. The methanation process in the first methanation reactor is isothermal. The second methanation reactor is an adiabatic methanation reactor.

[0038] Figure 10 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 1 The system includes two turbochargers, wherein an intercooling element 8b is arranged between the compressors of the respective turbochargers.

[0039] Figure 11 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 10 The system includes a second adiabatic methanation reactor arranged between the turbines of the respective turbochargers.

[0040] Figure 12 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 11The system includes a separate regenerator.

[0041] Figure 13 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbon-containing raw materials according to the present invention is shown, the system being... Figure 12 The system is similar, but includes a third methanation reactor and a thermal power plant for generating electricity, wherein an isothermal methanation process occurs in the third methanation reactor.

[0042] Figure 14 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes two turbochargers, both of which are arranged upstream of an adiabatic methanation reactor, and a regenerator is used to transfer heat from the product gas to the feed gas before it enters the first turbine.

[0043] Figure 15 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 14 The system includes an additional adiabatic methanation reactor and an additional regenerator.

[0044] Figure 16 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a two-stage methanation process with co-current and turbochargers located downstream of their respective methanation reactors, wherein the methane-rich gas produced in each methanation reactor enters the turbine (counter-current) before entering the compressor.

[0045] Figure 17 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown. This system is a combination of the following: [corresponding to...] Figure 1 The system consists of a first stage, a second stage with a countercurrent flow of methane-rich gas produced in a second methanation reactor in a downstream turbocharger, a third stage including a third methanation reactor with an isothermal methanation process controlled by a steam circuit, and a fourth methanation reactor that is polished to obtain a very high methane content in the methane-rich gas leaving the system.

[0046] Figure 18 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system including a turbocharger located downstream of the methanation reactor.

[0047] Figure 19 A schematic diagram of a system for producing methane from hydrogen and carbon-containing raw materials according to the present invention is shown, the system being similar toFigure 18 The system includes an additional regenerator arranged between the compressor and the heat exchanger, utilizing the heat flow from the methanation reactor.

[0048] Figure 20 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 18 The system includes an additional methanation stage.

[0049] Figure 21 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 18 The system includes an adiabatic methanation reactor and a downstream regenerator.

[0050] Figure 22 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 21 The system includes additional isothermal methanation stages and thermal power plants.

[0051] Figure 23 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbon-containing raw materials according to the present invention is shown. This system is similar to... Figure 16 The system includes an additional third methanation stage.

[0052] Figure 24 A schematic diagram of a complex exemplary system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, which combines several advantages of the system shown in the previous figure. Detailed Implementation

[0053] This invention relates to a method for producing methane-rich gas or methane and optionally power from hydrogen and carbonaceous feedstock in a system comprising at least one primary or multi-stage methanation process, comprising the following process steps:

[0054] a) Provide

[0055] Methanation reactor 1 is used for at least one or more stages of methanation process, wherein each methanation reactor includes an inlet for introducing feed gas and an outlet for methane-rich product gas, wherein the feed gas includes hydrogen and carbonaceous raw materials or methane-rich gas from a prior methanation stage.

[0056] A continuous gas pipeline having an inlet 6 for introducing hydrogen and carbonaceous raw materials and an outlet 7 for discharging methane-rich gas from the system; and

[0057] At least one turbocharger 2, comprising a compressor 3 and a turbine 4 mechanically connected via a common shaft 5, wherein the methanation reactor and the at least one turbocharger are connected via a continuous gas pipeline;

[0058] In this embodiment, at least one compressor is connected to and arranged in a portion of a continuous gas pipeline that defines the path from the introduction of raw materials to the output of methane-rich gas, particularly upstream, midway or downstream of the methanation reactor.

[0059] b) Introduce hydrogen and carbon-containing raw materials into the inlet of a continuous gas pipeline.

[0060] c) Producing methane-rich gas in a methanation reactor; and

[0061] d) The system pressure in a continuous gas pipeline is increased by using energy released during the methanation process via at least one compressor.

[0062] The present invention also relates to a system for producing methane-rich gas or methane and optional power from hydrogen and carbonaceous feedstock in at least one or more stages of methanation. The present invention further relates to a system for maintaining the production of methane-rich gas or methane and power from hydrogen and carbonaceous feedstock in at least one or more stages of methanation.

[0063] The system is used in the process of the present invention, comprising:

[0064] Methanation reactor 1 for at least one or more stages of methanation process, wherein each methanation reactor includes an inlet for introducing feed gas and an outlet for methane-rich product gas, wherein the feed gas includes hydrogen and carbonaceous raw materials or methane-rich gas from a prior methanation stage.

[0065] A continuous gas pipeline having an inlet 6 for introducing hydrogen and carbonaceous raw materials and an outlet 7 for discharging methane-rich gas from the system; and

[0066] At least one turbocharger 2, which includes a compressor 3 and a turbine 4 mechanically connected via a common shaft 5;

[0067] In this embodiment, at least one compressor is connected to and arranged in a portion of a continuous gas pipeline that defines the path from the introduction of raw materials to the output of methane-rich gas, particularly upstream, midway, or downstream of the methanation reactor.

[0068] Another aspect of the present invention is the use of the system according to the present invention in the methanation method described in the present invention.

[0069] The methanation process can be effectively maintained by using the method or system of the present invention, which utilizes the heat generated in the methanation reactor to drive a turbocharger to increase the pressure in the system. Therefore, the present invention can also be described as a process or system for maintaining the production of methane-rich gas or methane from hydrogen and carbonaceous feedstocks, with optional power, in a system comprising at least one single-stage or multi-stage methanation process as described above.

[0070] In the context of this invention, the feed gas is the gas entering the methanation reactor, and prior to the first methanation stage, the feed gas entering the methanation reactor comprises hydrogen and a carbon-containing raw material. The feed gas in subsequent methanation stages comprises the product gas from the previous methanation stage, which is a methane-rich gas produced in the previous methanation stage. In the context of this invention, the product gas is the gas exiting the methanation reactor. The product gas is a methane-rich or methanated gas, wherein the methane content is increased compared to the feed gas entering the same methanation reactor. Depending on the composition of the feed gas, such as the methane content in the feed gas, and the reaction conditions in the methanation reactor, the methane-rich product gas can have a methane concentration greater than about 97%. The carbon-containing raw material is preferably CO2 and / or CO.

[0071] The process and system can be operated using parameters that are known to those skilled in the art.

[0072] Carbonaceous raw materials are preferably supplied at atmospheric pressure. By using the compressor according to the invention, the pressure at the outlet of the continuous gas line is higher than the pressure at the inlet of the continuous gas line. Preferably, the pressure can be in the range of 0.1 bar to 100 bar, more preferably 1.5 bar to 25 bar, and even more preferably 2 bar to 8 bar. In a typical setup, the turbocharger compressor increases the pressure by 2 to 8 times, while the turbine decreases the pressure by 1.5 to 3 times. Specific performance depends on the quality of the turbocharger. For each turbocharger stage, a pressure increase of approximately 1.5 to 3 times can be expected. In Example 1 and... Figure 1 In the system shown, the inlet pressure is 1 bar. After the compressor, the pressure increases to 3 bar. The methanation process occurs at 3 bar. In the turbine, the pressure drops to 1.5 bar. The product gas leaves the system at a pressure of 1.5 bar.

[0073] In Example 12 and Figure 12 In the two-stage system shown, the pressure after the first compressor increases from 3 bar to 9 bar after the second compressor (a factor of 3 per stage). The first methanation process occurs at 9 bar. In the first turbine, the pressure drops to 4.5 bar. The second methanation process occurs at a temperature of 4.5 bar. In the second turbine, the pressure drops to 2.25 bar. The product gas exits the system at a pressure of 2.25 bar.

[0074] The process and system of the present invention are particularly effective for maintaining an ongoing methanation process. However, the above-described process and system can also be used to initiate a new methanation reaction. To initiate a new methanation reaction, the process of the present invention may further include preheating the methanation reactor before introducing hydrogen and carbonaceous feedstock into the inlet of a continuous gas pipeline. The temperature of the feedstock at the inlet of the continuous gas pipeline can range from ambient temperature (e.g., room temperature) to 100°C. The temperature at the inlet of the first methanation reactor is preferably at least about 130°C to 150°C, within which the exothermic reaction in the reactor sustains itself. The methanation process begins at a reactor temperature of about 200°C, more preferably about 250°C. The feed gas containing hydrogen and carbonaceous feedstock is electrically heated to about 200°C and fed into the system, thereby allowing the process to be started.

[0075] The process described in this invention may further include an additional step between steps b) and c): injecting water or steam directly into at least one methanation reactor, or into a continuous gas line upstream of the inlet for the feed gas introduced into at least one methanation reactor. This provides the advantage of increasing the mass flow rate in the turbine compared to a compressor, thereby allowing the compressor to provide an increased pressurization ratio. Furthermore, if desired, the temperature in the reactor can be limited by injecting steam or water directly into the methanation reaction or before it enters the methanation reactor. In these embodiments including the water / steam injection step, the system of this invention includes a water / steam injection unit for injecting water or steam directly into at least one methanation reactor or into a continuous gas line located upstream of the inlet for the feed gas. The water / steam injection unit includes a pipeline for transporting water and / or steam. Water is pumped toward the methanation reactor or the continuous gas line before entering the methanation reactor. Before the product gas leaves the system, the water is converted into steam or hot water in a heat exchanger element using the heat provided by the product gas.

[0076] The process of the present invention may also include, additionally or optionally, providing external energy to the compressor to facilitate initial compression of the hydrogen and carbonaceous raw materials prior to the start of the methanation process.

[0077] The location of the compressor in the process and system of this invention is not particularly limited, as long as the compressor is located where it can pressurize the gas in the continuous gas line. In one alternative, the compressor increases the pressure within the continuous gas line at a location between the inlet of the continuous gas line and the inlet of the methanation reactor; that is, the compressor can be located before the methanation reaction in the continuous gas line. This provides the advantage that the methanation process occurs at an increased pressure level. In another alternative, the compressor increases the pressure within the continuous gas line at a location between the outlet of the methanation reactor and the outlet of the continuous gas line; that is, the compressor can also be located after the methanation reactor in the continuous gas line. This provides the advantage of reducing the volumetric flow rate in the compressor. In the methanation reaction, four H2 molecules and one CO2 molecule react with two water molecules and one methane molecule, which corresponds to a volume reduction to approximately 3 / 5. Reducing the volumetric flow rate in the compressor allows for improved compressor performance.

[0078] In another alternative, the turbine can be located upstream of the compressor. This offers the advantage of further reducing the volumetric flow rate within the compressor. Before entering the compressor, the gas leaving the turbine can be cooled, and water vapor can be condensed and discharged. This further reduces the gas volume, especially when comparing the gas volume in the turbine to the gas volume in the compressor.

[0079] In embodiments with more than one turbocharger, one compressor may be located before the first methanation reactor, and another compressor may be located after the last methanation reactor. One or more compressors may also be located between any two methanation reactors.

[0080] In the process or system of the present invention, at least one turbocharger may be located upstream of the methanation reactor, and the heat generated in the methanation reaction may be supplied to the turbocharger via at least one heat exchanger at a location between the turbine and the compressor. Optionally, at least one turbocharger may be located downstream of the methanation reactor, and the heat generated in the methanation reaction may be supplied to the turbocharger via at least one heat exchanger at a location between the turbine and the compressor. Even when the turbocharger is located upstream or downstream of the methanation reactor, the heat exchanger ensures that heat is transferred to the turbocharger between its compressor and turbine components. Optionally, at least one turbocharger may be located between two methanation reactors, and the heat generated in the methanation reactor upstream of the turbocharger is supplied to the turbocharger via at least one heat exchanger before the turbocharger turbine inlet, preferably at a location between the turbine and the compressor.

[0081] The process or system described in this invention includes at least one turbocharger, and may also include multiple turbochargers. In some embodiments, two, three, or more turbochargers may be used. Each additional turbocharger increases the pressure in the system.

[0082] The process or system of the present invention can also be controlled by intermediate cooling or intermediate heating via a continuous gas pipeline through a heat exchanger element.

[0083] As used in this specification, the term "heat exchanger element / heat exchanger" may refer to an intercooling element, an interheating element, a regenerator, a gas cooling element, a preheating element, a condenser, and / or an evaporator. In a preferred embodiment, the heat exchanger may be a regenerator, wherein the regenerator transfers heat from the gas leaving the turbine to the hydrogen and carbonaceous feedstock for entry into the methanation reactor.

[0084] In the process or system described in this invention, at least one primary methanation process can be adiabatic, or at least one stage in a multi-stage methanation process can be adiabatic. During adiabatic processes, the gas temperature increases, improving turbine performance. In a preferred embodiment, the first stage takes place in an adiabatic methanation reactor, generating the highest temperature in the system. The highest temperature reached in the reactor can range from 350°C to 800°C, for example, 500°C to 800°C, and depends on the gas composition and pressure. A preferred highest temperature range is from about 430°C to about 720°C, for example, 630°C to about 720°C. The use of an adiabatic process allows the heat flow generated during the adiabatic process to be used to drive a turbocharger, particularly the compressor of the turbocharger. Further stages can also be adiabatic.

[0085] In the process or system described in this invention, at least one primary methanation process can be isothermal, or at least one stage of a multi-stage methanation process can be isothermal. Isothermal reactions occur in a lower temperature range of approximately 200°C to 300°C and offer the advantage of a better gas composition that can be used in downstream applications without further processing. A better gas composition means that more feedstock reacts to produce methane. The product gas from an isothermal process contains more methane than the product gas from an adiabatic process using the same feedstock. This is because the reaction equilibrium reached at the high temperatures in an adiabatic process is not optimal for the reaction of methane.

[0086] In a preferred embodiment of the invention, the process or system comprises a combination of at least one adiabatic process and at least one isothermal process, thereby enabling the user to benefit from the advantages provided by both processes. The number of methanation stages can be selected by those skilled in the art based on the requirements of the methane-rich gas produced in the system. Further stages allow for an increase in the concentration of methane in the product gas.

[0087] In the isothermal methanation process of this invention, the temperature in the methanation reactor is controlled by a thermal power plant.

[0088] In the context of this invention, a thermal power plant is a system that converts thermal energy into electrical energy. When a thermal power plant is present in the system or process of this invention, the system or process can be used to produce methane-rich gas and electricity. For example, a steam-driven turbine can convert heat into mechanical power as an intermediate medium for electrical energy. The steam turbine is connected to the thermal power plant piping, through which the working medium is conducted. In a preferred embodiment, the working medium is water and / or steam.

[0089] Alternatively, the working medium can be hot oil or molten salt. Hot oil or molten salt is typically used in the intermediate loop to store heat. The heat stored in the hot oil / molten salt loop is then transferred to the steam loop. Therefore, this system will include an additional loop, making the system more complex compared to a system using direct cooling with water / steam. On the other hand, with indirect cooling via the hot oil / molten salt loop, the reactor does not need to be designed to operate at pressures up to 80 bar, as is the case with direct cooling using a water / steam loop. This is because the hot oil loop does not require pressure.

[0090] In a thermal power plant, the working medium, such as water, is heated to become steam and drives a steam turbine, which in turn drives a generator. In several embodiments of the invention, the heat flow generated in an isothermal methanation reactor can be used to heat the working medium in the thermal power plant system. Furthermore, the working medium can be preheated in heat exchanger elements, wherein the heated methanation gas preheats the working medium before it leaves the system. After passing through the turbine, the steam condenses in a condenser and is recycled to the heating point.

[0091] In the process or system of the present invention, the turbine of the turbocharger can reduce the pressure of the gas leaving the methanation reactor. Alternatively or additionally, the turbine can be located in the steam circuit of a thermal power plant and reduce the pressure of the working medium carried in the thermal power plant piping used to control the temperature of another methanation reactor.

[0092] In the process or system of the present invention, a portion of the heat generated during methanation can be used in a turbocharger, while another portion (preferably a larger portion) can be used to generate steam or power. Since it is thermodynamically impossible to utilize all the heat generated during methanation in the turbocharger, it is advantageous to use the remaining heat for power generation. This makes the process and system more efficient.

[0093] The invention is further illustrated in the following examples.

[0094] Example

[0095] Example 1

[0096] Figure 1 An embodiment of the system and process of the present invention is shown.

[0097] Figure 1 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes a turbocharger comprising a compressor 3 and a turbine 4 mechanically connected by a common shaft 5, and an adiabatic (uncooled) methanation reactor 1 arranged between the compressor and the turbine. The inlet pressure is 1 bar(a), and the temperature is 20°C. The feed gas consists of, for example, 4 mol / s H2 and 1 mol / s CO2. Hydrogen and the carbonaceous feedstock pass through the compressor. The pressure at the compressor outlet is, for example, 3 bar(a). It is assumed that the isentropic efficiency of the compressor and turbine is 90%. Then, in the adiabatic methanation reactor at 3 bar(a), a methanated gas of approximately 0.48 mol / s methane and an outlet temperature of 628°C is generated. The generated methane-rich gas exits the methanation reactor and enters the turbine. The gas expands in the turbine to approximately 1.5 bar(a) to drive the compressor. Approximately 17.5 kW of power is transmitted through the turbocharger shaft. The expanded methane-rich gas then exits the system. To achieve complete conversion of the feed gas, at least one additional methanation reactor can be added after the turbine in the illustrated embodiment. This methanation reactor can, for example, operate isothermally at 280°C, wherein the temperature of methanation is controlled via a thermal power plant.

[0098] Example 2

[0099] Figure 2 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes a turbocharger 2 comprising a compressor 3 and a turbine 4 mechanically connected by a common shaft 5, and an adiabatic methanation reactor 1 disposed between the compressor and the turbine. The system also includes a heat exchanger 8. The heat exchanger is a regenerator, wherein the produced methane-rich gas heats the hydrogen and carbonaceous feedstock leaving the compressor. The regenerator (50 K (Pinch)) raises the temperature at the inlet of the methanation reactor to approximately 513 °C (compared to...). Figure 1 The temperature of the methanated gas leaving the reactor is approximately 702°C (compared to approximately 131°C in the system shown). Figure 1 Compared to approximately 628°C in the system shown). This results in a reduction in methane production at the reactor outlet (0.26 mol / s methane). However, the increased temperature allows the turbine to operate at a lower pressure differential to drive the compressor. Therefore, the methane-rich gas can provide an additional pressure of 1.7 bar (compared to...). Figure 1 (Compared to 1.5 bar in the system shown). The temperature of the methane-rich gas leaving the system after passing through the regenerator is approximately 181°C.

[0100] Example 3

[0101] Figure 3 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes a turbocharger comprising a compressor 3 and a turbine 4 mechanically connected by a common shaft 5, and a methanation reactor 1 disposed downstream of the compressor and turbine. The system also includes a heat exchanger 8. The heat exchanger is a regenerator in which the produced methane-rich gas heats the hydrogen and carbonaceous feedstock leaving the compressor.

[0102] Example 4

[0103] Figure 4 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes a turbocharger comprising a compressor 3 and a turbine 4 mechanically connected by a common shaft 5, and a methanation reactor 1 disposed upstream of the compressor and turbine. The system also includes two heat exchangers 8 / 8a. The produced methane-rich gas passes through a heat exchanger, which is a regenerator 8 disposed between the compressor and turbine, wherein the produced methane-rich gas leaving the compressor flows counter-currently relative to the produced methane-rich gas leaving the methanation reactor. Vapor generated in the reaction condenses in another heat exchange element (gas cooling element 8a), causing condensate 9 to leave the system before the methane-rich gas enters the compressor.

[0104] Example 5

[0105] Figure 5 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system is similar to... Figure 4 The system shown. The heat flow 10 from the methanation reaction is used to recover the methane-rich gas produced before it enters the turbine.

[0106] Example 6

[0107] Figure 6 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes a turbocharger having a countercurrent flow of the produced methane-rich gas, which enters a turbine before entering the compressor of the turbocharger. The produced methane-rich gas enters the turbine and is then cooled in a regenerator by the countercurrent flow of hydrogen and carbonaceous feedstock. Vapor generated in the reaction condenses in another heat exchange element (intermediate cooling element 8b), causing condensate 9 to exit the system before the methane-rich gas enters the compressor. The methane-rich gas exiting the compressor leaves the system.

[0108] Example 7

[0109] Figure 7 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 1 The system also includes a water / steam injection unit, which includes piping through which water is guided. Water 11 is pumped by pump 12 through heat exchangers 8c / 8d, which may be preheating elements 8c or evaporators 8d, wherein the steam generated in the methanation reaction is condensed and the condensate leaves the system, and the water is heated to obtain hot water / steam 13 for injection into the methanation reactor.

[0110] Example 8

[0111] Figure 8 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 7 The system comprises two methanation reactors. The first methanation reactor is an adiabatic methanation reactor. The heated methane-rich gas produced in the first methanation reactor is used to heat the methane-rich gas leaving the second methanation reactor before it enters the turbine. The second methanation reactor is cooled by a boiling water cooler. The methanation process in the second methanation reactor is isothermal. The water / steam injection unit is similar to... Figure 7 The water / steam injection unit is shown. Before leaving the system, the pumped water is heated to hot water 14 using the waste heat from the generated methane-rich gas in a preheating heat exchanger, and the hot water is further heated to obtain steam 15 using the heat flow generated in a second methanation reactor in another heat exchanger. The steam is injected into a continuous gas pipeline at a point downstream of the second methanation reactor but upstream of the turbine.

[0112] Example 9

[0113] Figure 9A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous feedstock, according to the present invention, is shown. The system comprises two methanation reactors. A first methanation reactor is cooled by a boiling water cooler. The methanation process in the first methanation reactor is isothermal. The second methanation reactor is an adiabatic methanation reactor. The heated methane produced in the first methanation reactor is used to heat water in a thermal power plant, which includes a steam loop. In one loop, water is pumped through thermal power plant piping to a heat exchanger and heated by countercurrent flow of water relative to the methane-rich gas produced in the first methanation reactor. Condensate from the methane-rich gas stream exits the system at this point in the loop. In another loop, water is pumped through thermal power plant piping to another heat exchanger and heated by countercurrent flow of water to the methane-rich gas produced in the second methanation reactor. Hot water from both loops enters the other heat exchanger, resulting in steam generation. The heat flow from the first methanation reactor is used to heat the water, thereby causing cooling of the first methanation reactor. Steam is used to drive turbine 4 of the turbocharger. Residual pressure is used in the steam turbine for power generation 16. The residual steam is cooled in a condenser and fed to a pump, thus completing the loop. The power generated by the steam turbine can be used in part to drive the pumps in the steam loop and / or for other purposes, such as output to the grid. Hydrogen and carbonaceous feedstock enter the first methanation reactor. The resulting methane-rich gas exits the first methanation reactor, is cooled in a heat exchanger, and causes the condensate to leave the system. The methane-rich gas then enters the compressor before entering the second methanation reactor. The resulting methane-rich gas exits the second methanation reactor to heat water flowing from the pump to the turbine of the turbocharger before leaving the system.

[0114] Example 10

[0115] Figure 10 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being... Figure 1 The system is similar, but includes two turbochargers, with an intercooling element arranged between the compressors of the respective turbochargers.

[0116] Example 11

[0117] Figure 11 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being... Figure 10 The system is similar, but includes a second adiabatic methanation reactor arranged between the turbines of the respective turbochargers.

[0118] Example 12

[0119] Figure 12A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 11 The system includes an additional regenerator, wherein the methane-rich gas produced before leaving the system is used to heat hydrogen and carbonaceous raw materials before entering the first methanation reactor.

[0120] Example 13

[0121] Figure 13 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 12 The system includes a third methanation reactor, in which an isothermal methanation process occurs. The third methanation reactor interacts with a thermal power plant, which includes a steam turbine capable of generating electricity using the heat flow generated in the third methanation reactor.

[0122] Example 14

[0123] Figure 14 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes two turbochargers, wherein an intercooling element 8b is arranged between the compressors of the respective turbochargers. The methane-rich gas produced exiting the methanation reactor is used to heat the hydrogen and carbonaceous feedstock in a regenerator. The methanation reactor is arranged downstream of the turbochargers.

[0124] Example 15

[0125] Figure 15 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 14 The system comprises a second adiabatic methanation reactor. The methane-rich gas produced in the second methanation reactor is used to heat hydrogen and carbonaceous feedstock at a location between the two turbines.

[0126] Example 16

[0127] Figure 16 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown. The system includes a two-stage methanation process with a regenerator and a turbocharger located downstream of their respective methanation reactors, wherein the methane-rich gas produced in each methanation reactor enters the turbine (countercurrent) before entering the compressor.

[0128] Example 17

[0129] Figure 17A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being a combination of the following: corresponding to Figure 1 The system consists of a first stage, a second stage in which a countercurrent flow of methane-rich gas is generated in a second methanation reactor in a downstream turbocharger, a third stage including a third methanation reactor with an isothermal methanation process controlled by a steam loop, and a fourth methanation reactor for polishing to obtain a very high methane content in the methane-rich gas leaving the system.

[0130] Example 18

[0131] Figure 18 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous feedstock according to the present invention is shown. The system includes a turbocharger located downstream of a methanation reactor. The heat flow from the methanation reactor is used to heat the methane-rich gas exiting the compressor before it enters the turbine. The methane-rich gas produced in the methanation reactor is cooled before entering the compressor, and the condensate exits the system. A regenerator is used to heat the hydrogen and carbonaceous feedstock before they enter the methanation reactor.

[0132] Example 19

[0133] Figure 19 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 18 The system includes an additional regenerator arranged between the compressor and the heat exchanger to utilize the heat flow from the methanation reactor.

[0134] Example 20

[0135] Figure 20 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 18 The system includes an additional methanation stage. This additional methanation reactor is cooled by the thermal power plant using a heat flow to evaporate water in the power plant's steam loop to generate electricity.

[0136] Example 21

[0137] Figure 21 A schematic diagram of a system for producing methane-rich gas from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 18 The system comprises an adiabatic methanation reactor and a downstream heat exchanger. The methane-rich gas exiting the methanation reactor is used to heat the methane-rich gas exiting the compressor.

[0138] Example 22

[0139] Figure 22 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 21 The system includes an additional methanation stage. This additional methanation reactor is cooled by the thermal power plant using a heat flow to evaporate water in the power plant's steam loop to generate electricity.

[0140] Example 23

[0141] Figure 23 A schematic diagram of a system for producing methane-rich gas and power from hydrogen and carbonaceous raw materials according to the present invention is shown, the system being similar to Figure 16 The system includes an additional third methanation stage. This additional third methanation reactor is cooled by the thermal power plant using a heat flow to evaporate water in the power plant's steam loop to generate electricity.

[0142] Example 24

[0143] Figure 24 A schematic diagram of a complex exemplary system according to the present invention for producing methane-rich gas from hydrogen and carbonaceous feedstock is shown. Following an adiabatic methanation stage is the regenerative use of the heat flow generated in the first methanation reactor, followed by intercooling to guide the condensate away from the system, and then two-stage compression in compressors of two turbochargers. After a second adiabatic methanation stage injected with hot water / steam, regenerative heating and expansion occur in the turbines of the corresponding turbochargers. After another expansion step in the turbines of a third turbocharger, the methane is compressed in the compressor of the third turbocharger and enters the third methanation reactor. The heat flow from the third methanation reactor is used to generate steam injected into the second methanation reactor. The advantage of this complex system is the significantly increased mass flow rate through the expansion turbines, thereby enabling very high outlet pressures at the system end, for example, 50 bar(a) at an inlet pressure of 1 bar(a). Pressures of approximately 5-20 bar(a) are obtained due to the two-stage compression before the second methanation stage. Combined with intercooling and condensate separation, very high methane concentrations (>97%) can be achieved. Another advantage is that no complex cooling circuit is required because the methanation stage is adiabatic. Since the first (high-temperature) stage operates only at ambient pressure, the outlet temperature is inherently limited to approximately 600°C.

[0144] List of symbols in the attached diagram

[0145] 1: Methanation reactor

[0146] 2: Turbocharger

[0147] 3: Compressor

[0148] 4: Turbine

[0149] 5: Shaft

[0150] 6: Inlet of a continuous gas pipeline used for introducing hydrogen and carbon-containing raw materials (feed gas)

[0151] 7: Outlet for outputting the generated methane-rich gas (product gas)

[0152] 8: Heat exchanger / regenerator

[0153] 8a: Gas cooling element

[0154] 8b: Intermediate cooling element

[0155] 8c: Preheating element

[0156] 8d: Evaporator

[0157] 8e: Condenser

[0158] 9: Condensate discharged

[0159] 10: Heat flow

[0160] 11: Water

[0161] 12: Pump

[0162] 13: Hot water / steam

[0163] 14: Hot water

[0164] 15: Steam

[0165] 16: Steam turbines used for power generation

Claims

1. A method for producing methane-rich gas from hydrogen and carbonaceous feedstock in a system comprising at least one or more stages of methanation process. The method includes the following process steps: a) Provide Methanation reactor (1), for the at least one or more stage methanation processes, wherein, Each methanation reactor includes an inlet for introducing feed gas and an outlet for methane-rich product gas, wherein the feed gas includes hydrogen and carbonaceous raw materials or methane-rich gas from a prior methanation stage. A continuous gas pipeline having an inlet (6) for introducing hydrogen and carbonaceous raw materials and an outlet (7) for discharging the methane-rich gas from the system; and At least one turbocharger (2), the at least one turbocharger comprising a compressor (3) and a turbine (4) mechanically connected by a common shaft (5), wherein the methanation reactor and the at least one turbocharger are connected via the continuous gas pipeline; The at least one compressor is connected to the continuous gas pipeline and is arranged in a portion of the continuous gas pipeline, which defines a path from the introduction of the raw material to the output of the methane-rich gas. b) Introducing the hydrogen and carbon-containing raw materials into the inlet of the continuous gas pipeline. c) Producing methane-rich gas in the methanation reactor; and d) The system pressure in the continuous gas pipeline is increased by using the energy released during the methanation process via the at least one compressor.

2. The method according to claim 1, wherein, The continuous gas pipeline defines the path from the introduction of raw materials to the output of methane-rich gas upstream, in the middle, or downstream of the methanation reactor.

3. The method according to claim 1, further comprising an additional step between step b) and c): Water or steam is injected directly into at least one methanation reactor, or into the continuous gas pipeline, wherein the continuous gas pipeline is located upstream of the inlet for the feed gas introduced into the at least one methanation reactor and / or the turbocharger turbine.

4. The method according to any one of claims 1-3, wherein, In step a), a thermal power plant is provided having a working medium conducted in a thermal power plant pipeline, wherein the thermal power plant is connected to at least one of the methanation reactors via at least one heat exchanger (8) or to a gas flow from the methanation reactor, and wherein the thermal power plant generates electricity, wherein optionally the thermal power plant is a steam turbine (16) having steam (15) conducted in a steam turbine circulation pipeline.

5. The method according to claim 4, wherein, The turbine of the at least one turbocharger is connected to the continuous gas line, or, when a thermal power plant line exists, to one of the thermal power plant lines; and / or It also includes step e), discharging the methane-rich gas from the system at the outlet of the continuous gas pipeline; and / or wherein the carbon-containing raw material is CO2 and / or CO; and / or wherein the hydrogen and the carbon-containing raw material are provided at atmospheric pressure; and / or wherein the pressure at the outlet of the continuous gas pipeline is higher than the pressure at the inlet of the continuous gas pipeline.

6. The method according to claim 4, further comprising preheating the methanation reactor prior to step b) of claim 1; and / or It also includes providing external energy to the compressor to initially compress the hydrogen and the carbonaceous raw material prior to the methanation process.

7. The method according to claim 4, wherein, The one or more compressors increase the pressure within the continuous gas line at a location located between the inlet of the continuous gas line and the inlet of the first methanation reactor; and / or wherein, The one or more compressors increase the pressure within the continuous gas pipeline at a location between the outlet of the methanation reactor and the outlet of the continuous gas pipeline; and / or wherein, The turbine is located upstream of the one or more compressors.

8. The method according to claim 4, wherein, Use multiple turbochargers; or one of them. Intermediate cooling or heating of the continuous gas pipeline is carried out via a heat exchanger (8); and / or wherein, The at least one single-stage methanation process is adiabatic, or at least one stage of the multi-stage methanation process is adiabatic.

9. The method according to claim 8, wherein, The plurality of turbochargers may be two, three or more turbochargers.

10. The method according to claim 4, wherein, The at least one primary methanation process is isothermal, or at least one stage of the multi-stage methanation process is isothermal, wherein, in the isothermal process, the temperature in the methanation reactor is controlled by the thermal power plant.

11. The method according to claim 4, wherein, The turbine is capable of reducing the pressure of the gas leaving the methanation reactor; or wherein, when thermal power plant piping is present, the turbine is capable of reducing the pressure of the working medium transmitted in the thermal power plant piping used to control the temperature of the methanation reactor; and / or wherein, When a heat exchanger is present, the heat exchanger (8) is a regenerator, wherein the regenerator transfers heat from the gas leaving the turbine to the hydrogen and the carbonaceous raw material before the hydrogen and the carbonaceous raw material enter the methanation reactor.

12. The method according to claim 4, wherein, The at least one turbocharger is located upstream of the methanation reactor, and the heat generated in the methanation reactor is supplied to the turbocharger via at least one heat exchanger at a location between the turbine and the compressor; Or one of them, The at least one turbocharger is located downstream of the methanation reactor, and the heat generated in the methanation reactor is supplied to the turbocharger via at least one heat exchanger at a location between the turbine and the compressor; or wherein, The at least one turbocharger is located between the two methanation reactors, and the heat generated in the methanation reactor located upstream of the turbocharger is supplied to the turbocharger via at least one heat exchanger before the turbocharger turbine inlet.

13. The method according to claim 12, wherein, The heat generated in the methanation reactor located upstream of the turbocharger is supplied to the turbocharger via at least one heat exchanger at a location between the turbine and the compressor.

14. The method according to claim 4, wherein, A portion of the heat generated during the methanation process is used in the turbocharger, while another portion is used to generate steam or power.

15. The method according to claim 14, wherein, The other part is a larger portion of the heat generated during the methanation process, used to produce steam or power.

16. A system for producing methane-rich gas from hydrogen and carbonaceous feedstock in at least one or more stages of methanation, wherein, The system includes: Methanation reactor (1) for the at least one or more-stage methanation processes, wherein each methanation reactor includes an inlet for introducing feed gas and an outlet for methane-rich product gas, wherein the feed gas includes hydrogen and carbonaceous raw materials or methane-rich gas from a prior methanation stage. A continuous gas pipeline having an inlet (6) for introducing hydrogen and carbonaceous raw materials and an outlet (7) for discharging the methane-rich gas from the system; and At least one turbocharger (2), the at least one turbocharger (2) comprising a compressor (3) and a turbine (4) mechanically connected by a common shaft (5); The at least one compressor is connected to and arranged in a portion of the continuous gas pipeline, which defines a path from the introduction of the raw material to the output of the methane-rich gas.

17. The system according to claim 16, wherein, The continuous gas pipeline defines a path from the introduction of the raw material to the output of the methane-rich gas upstream, in the middle, or downstream of the methanation reactor.

18. The system of claim 16 further includes a water / steam injection unit for injecting water or steam directly into the at least one methanation reactor, or into the continuous gas line upstream of the inlet for introducing feed gas.

19. The system according to claim 16 or 17, further comprising a thermal power plant having a working medium conducted in the thermal power plant piping, wherein, The methanation reactor and the at least one turbocharger are connected via the continuous gas pipeline, wherein the thermal power plant is connected to at least one of the methanation reactors or to a gas flow from the methanation reactor via at least one heat exchanger (8), and wherein the thermal power plant is configured to generate electricity.

20. The system according to claim 19, wherein the thermal power plant is a steam turbine (16) having a steam turbine circulation pipeline.

21. The system according to claim 16, 17 or 18, wherein, The at least one turbine is connected to the continuous gas pipeline, or, if a thermal power plant pipeline exists, to one of the thermal power plant pipelines.

22. The system according to any one of claims 16 to 21 is used for the method according to any one of claims 1 to 15.

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