A production system for preparing green methane without circulation
By introducing H2 into the methanation reactor in stages and introducing steam at the first inlet, the problem of low CH4 yield in CO2 methanation reaction is solved, achieving efficient production of green methane and reducing equipment investment and operating costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WISON ENG
- Filing Date
- 2025-06-20
- Publication Date
- 2026-06-23
AI Technical Summary
In existing technologies, the thermodynamic limitations of CO2 methanation reactions result in low CH4 yields. Traditional methanation processes require circulating compressors, increasing equipment investment and operating energy consumption, while also posing operational risks.
The reaction process is controlled by introducing H2 into the methanation reactor in stages, combined with steam control of the reaction temperature rise. Steam is introduced through the inlet of the first-stage methanation reactor to control the reaction process and avoid the use of a circulating compressor.
This has enabled the efficient production of green methane, reduced equipment investment and operating costs, and improved operational reliability and ease of control.
Smart Images
Figure CN224388740U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of waste gas treatment technology, and in particular to a production system for the non-recycling preparation of green methane. Background Technology
[0002] With global climate issues becoming increasingly prominent, energy conservation and emission reduction have received widespread attention. Carbon dioxide (CO2), as a major greenhouse gas affecting the climate, urgently requires effective methods to reduce emissions. In my country, the energy structure dominated by thermal power generation results in persistently high CO2 emissions. Therefore, many coal-fired power plants and other enterprises have introduced carbon capture, utilization, and storage (CCUS) technologies.
[0003] However, if the CO2 obtained from carbon capture cannot be utilized with high added value, it will greatly increase the project cost and make it difficult to promote on a large scale. On the other hand, the large amount of captured CO2 will have nowhere to be disposed of, which will greatly reduce the emission reduction effect.
[0004] On the other hand, with the rapid development of renewable energy, significant breakthroughs have been made in fields such as wind and solar power generation and photovoltaic hydrogen production, leading to continuous cost reductions. However, due to limitations in energy storage technology and grid regulation capabilities, renewable energy in many regions is abandoned due to difficulties in absorption, making the search for efficient utilization methods an important issue.
[0005] Utilizing carbon capture CO2 and green hydrogen to produce methane presents an excellent solution to the aforementioned problems. From an emissions reduction perspective, this provides an efficient outlet for captured CO2, converting CO2 that might otherwise be released back into the atmosphere into stable methane, achieving true carbon reduction. From an energy utilization perspective, on the one hand, it successfully realizes the reaction of abandoned renewable energy with CO2 through green hydrogen as an intermediate step to produce methane, achieving cross-form energy storage and conversion, greatly improving energy efficiency; on the other hand, methane, as a high-quality clean energy source, can be widely used in heating, power generation, and chemical raw materials, effectively supplementing energy supply and reducing dependence on traditional fossil fuels, thus promoting a cleaner and more sustainable energy structure.
[0006] CO2 methanation is one of the most promising methods for reducing carbon emissions, and its reaction equation is as follows:
[0007] CO2+4H2=CH4+2H2OΔH=-164.9kJ / mol
[0008] This reaction is strongly exothermic, and the formation of CH4 is thermodynamically limited. However, decreasing the operating temperature affects the reaction kinetics and reduces the yield of CH4. Therefore, temperature control is crucial in the preparation of CH4 using green CO2 and green hydrogen.
[0009] Therefore, there is an urgent need for a simple and efficient CO2 methanation device, which can turn green CO2 obtained by carbon capture or other technologies into a valuable resource, and make reasonable use of hydrogen produced by renewable energy power generation to promote the transformation of the energy structure. Utility Model Content
[0010] The purpose of this invention is to provide a non-circulating production system for green methane to overcome the shortcomings of the existing technology. Traditional methanation processes using product gas temperature control require a circulating compressor, which greatly increases equipment investment and operating energy consumption. At the same time, there are also significant operational risks in the process. This invention proposes a method of introducing H2 into the methanation reactor in stages to reasonably control the reaction process. Meanwhile, water vapor is introduced into the inlet of the first-stage methanation reactor to control the temperature rise of the methanation reaction. The process is simple, easy to operate, highly reliable, and has lower equipment investment and operating costs.
[0011] The objective of this utility model can be achieved through the following technical solutions:
[0012] The purpose of this invention is to provide a non-circulating green methane production system. This system includes a CO2 feed assembly, a green hydrogen feed assembly, a steam inlet assembly, a first-stage methanation reactor, an intermediate-stage methanation reactor, a gas-liquid separator I, a final-stage isothermal methanation reactor, and a gas-liquid separator II. The CO2 feed assembly is used to introduce the raw material CO2 and is connected to the inlet of the first-stage methanation reactor. The green hydrogen feed assembly is used to introduce the raw material green hydrogen and is connected to the first-stage methanation reactor. The intermediate-stage methanation reactor is connected to the inlet of the intermediate-stage methanation reactor; the steam inlet assembly is used to introduce steam; the steam inlet assembly is connected to the inlet of the first-stage methanation reactor; the outlet of the first-stage methanation reactor is connected to the inlet of the intermediate-stage methanation reactor; the outlet of the intermediate-stage methanation reactor is connected to the inlet of gas-liquid separator I; the gas phase outlet of gas-liquid separator I is connected to the inlet of the final-stage isothermal methanation reactor; the outlet of the final-stage isothermal methanation reactor is connected to the inlet of gas-liquid separator II; the gas phase outlet of gas-liquid separator II is used to obtain green methane.
[0013] Furthermore, the intermediate-stage methanation reactor includes a second-stage methanation reactor and a third-stage methanation reactor connected in sequence; the outlet of the first-stage methanation reactor is connected to the inlet of the second-stage methanation reactor; the outlet of the third-stage methanation reactor is connected to the inlet of the gas-liquid separator I; a cooler is provided between the outlet of the first-stage methanation reactor and the inlet of the second-stage methanation reactor; a cooler is also provided between the outlet of the second-stage methanation reactor and the inlet of the third-stage methanation reactor.
[0014] Furthermore, the first-stage methanation reactor, the second-stage methanation reactor, and the third-stage methanation reactor are fixed-bed adiabatic reactors.
[0015] Furthermore, a cooler is provided between the outlet of the first-stage methanation reactor and the inlet of the intermediate-stage methanation reactor; a cooler is provided between the outlet of the intermediate-stage methanation reactor and the inlet of gas-liquid separator I; a preheater is provided between the gas phase outlet of gas-liquid separator I and the inlet of the final-stage isothermal methanation reactor; and a cooler is provided between the outlet of the final-stage isothermal methanation reactor and the inlet of gas-liquid separator II.
[0016] Furthermore, the CO2 feed assembly includes a CO2 feed pipe and a CO2 feed preheater; the CO2 feed pipe is connected to the inlet of the CO2 feed preheater; the outlet of the CO2 feed preheater is connected to the inlet of the first-stage methanation reactor; the CO2 feed preheater is used to preheat the raw material CO2 from the CO2 feed pipe.
[0017] Furthermore, the green hydrogen feed assembly includes a green hydrogen feed pipeline, a green hydrogen feed preheater, a green hydrogen inlet pipeline I, a first-stage green hydrogen inlet branch, and an intermediate-stage green hydrogen inlet branch; the green hydrogen feed pipeline is connected to the inlet of the green hydrogen feed preheater; the outlet of the green hydrogen feed preheater is connected to the green hydrogen inlet pipeline I; the green hydrogen inlet pipeline I is connected to the first-stage green hydrogen inlet branch and the intermediate-stage green hydrogen inlet branch respectively; the first-stage green hydrogen inlet branch is connected to the inlet of the first-stage methanation reactor; and the intermediate-stage green hydrogen inlet branch is connected to the inlet of the intermediate-stage methanation reactor.
[0018] Furthermore, both the first-stage green hydrogen inlet branch and the intermediate-stage green hydrogen inlet branch are equipped with green hydrogen flow control devices; the green hydrogen flow control devices are used to control the green hydrogen feed flow rate in stages and to control the reaction progress in the first-stage methanation reactor and the intermediate-stage methanation reactor.
[0019] Furthermore, the steam inlet assembly includes a steam feed pipe; the steam feed pipe is connected to the inlet of the first-stage methanation reactor.
[0020] Furthermore, the steam inlet assembly also includes a temperature control interlock device; the steam inlet pipe is connected to the temperature control interlock device, which is used to control the flow rate of steam entering the first-stage methanation reactor and maintain the temperature rise of the outlet gas of the first-stage methanation reactor.
[0021] Furthermore, the non-recycled green methane production system also includes a cooling unit; the cooling unit is connected to the final-stage isothermal methanation reactor; the cooling unit includes a steam drum, a boiler water inlet pipe, and a steam outlet pipe; the steam drum is connected to the final-stage isothermal methanation reactor and forms a heat exchange loop; the boiler water inlet pipe and the steam outlet pipe are respectively connected to the steam drum; the boiler water inlet pipe is used to introduce boiler water into the steam drum; the steam outlet pipe is used to discharge steam from the steam drum.
[0022] Furthermore, the cooling unit also includes a pressure control device; the pressure control device is connected to the steam discharge pipe; the pressure control device is used to control the flow rate of steam discharge and maintain the pressure inside the steam drum.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] The non-circulating green methane production system provided by this invention addresses the traditional methanation process that uses product gas temperature control, which requires a circulating compressor, significantly increasing equipment investment and operating energy consumption. Furthermore, the process carries considerable operational risks. This invention proposes a method of staged H2 entry into the methanation reactor to rationally control the reaction process. Simultaneously, water vapor is introduced at the inlet of the first-stage methanation reactor to control the temperature rise of the methanation reaction. The process is simple, convenient, highly reliable, and has lower equipment investment and operating costs. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the production system for the non-recycling preparation of green methane according to this invention.
[0026] The numbers in the diagram are as follows:
[0027] 1-CO2 feed line; 2-CO2 feed preheater; 3-CO2 preheating line; 4-First-stage feed collection line; 5-First-stage methanation reactor; 6-First-stage methanation reactor bottom discharge line; 7-First-stage intercooler; 8-First-stage methanation conveying line; 9-Second-stage feed collection line; 10-Second-stage methanation reactor; 11-Second-stage methanation reactor bottom discharge line; 12-Second-stage intercooler; 13-Second-stage methanation... 14-Third-stage feed collection pipeline; 15-Third-stage methanation reactor; 16-Third-stage methanation reactor bottom discharge pipeline; 17-Third-stage intercooler; 18-Third-stage methanation conveying pipeline; 19-Gas-liquid separator I; 20-Gas phase outlet pipeline I; 21-Final-stage methanation reactor feed preheater; 22-Gas phase conveying pipeline I; 23-Final-stage isothermal methanation reactor; 24-Final-stage isothermal methanation reactor bottom discharge pipeline; 25- Product cooler; 26-Final stage methanation conveying pipeline; 27-Gas-liquid separator II; 28-Gas phase outlet pipeline II; 29-Liquid phase outlet II; 30-Green hydrogen feed pipeline; 31-Green hydrogen feed preheater; 32-Green hydrogen inlet pipeline I; 33-Green hydrogen inlet pipeline II; 34-Green hydrogen inlet pipeline III; 35-Green hydrogen staged feed pipeline I; 36-Green hydrogen conveying pipeline I; 37-Green hydrogen flow control device I; 38-Green hydrogen staged feed pipeline II; 39-Green hydrogen conveying pipe 40-Green Hydrogen Flow Control Device II; 41-Green Hydrogen Stage Feed Pipe III; 42-Green Hydrogen Transmission Pipe III; 43-Green Hydrogen Flow Control Device III; 44-Liquid Phase Outlet I; 45-Steam Feed Pipe; 46-Steam Transmission Pipe; 47-Temperature Control Interlock Device; 48-Boiler Water Inlet Pipe; 49-Steam Drum; 50-Pressure Control Device; 51-Steam Outlet Pipe; 52-Steam Discharge Pipe; 53-Heat Exchange Pipe I; 54-Heat Exchange Pipe II. Detailed Implementation
[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Any component models, material names, connection structures, control methods, etc., not explicitly described in this technical solution are considered common technical features disclosed in the prior art.
[0029] The embodiments described in this application are only a part of the embodiments of this utility model and cannot represent all embodiments. Other embodiments obtained by those skilled in the art without creative effort on this application should fall within the protection scope of this utility model.
[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0031] It should be noted that in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.
[0032] In the following embodiments, green hydrogen is directly produced through renewable energy power generation such as solar and wind power, and the production process generates virtually no greenhouse gases. The raw material CO2 is obtained through carbon capture or other technological means.
[0033] Example 1
[0034] like Figure 1 As shown, this embodiment provides a non-recirculating green methane production system, including a CO2 feed assembly, a green hydrogen feed assembly, a steam inlet assembly, a first-stage methanation reactor 5, an intermediate-stage methanation reactor, a gas-liquid separator I 19, a final-stage isothermal methanation reactor 23, and a gas-liquid separator II 27. The intermediate-stage methanation reactor includes a second-stage methanation reactor 10 and a third-stage methanation reactor 15 connected in sequence.
[0035] The first-stage methanation reactor 5, the second-stage methanation reactor 10, and the third-stage methanation reactor 15 are fixed-bed adiabatic reactors.
[0036] The CO2 feed assembly is used to introduce raw material CO2; the CO2 feed assembly is connected to the inlet of the first-stage methanation reactor 5; the CO2 feed assembly includes a CO2 feed pipe 1, a CO2 feed preheater 2, and a CO2 preheating pipe 3; the CO2 feed pipe 1 is connected to the inlet of the CO2 feed preheater 2; the outlet of the CO2 feed preheater 2 is connected to the CO2 preheating pipe 3, and the CO2 preheating pipe 3 is connected to the inlet of the first-stage methanation reactor 5; the CO2 feed preheater 2 is used to preheat the raw material CO2 from the CO2 feed pipe 1 and then introduce the preheated raw material CO2 into the first-stage methanation reactor 5.
[0037] The green hydrogen feed assembly is used to introduce raw material green hydrogen; the green hydrogen feed assembly is connected to the inlets of the first-stage methanation reactor 5, the second-stage methanation reactor 10, and the third-stage methanation reactor 15, respectively; the green hydrogen feed assembly includes a green hydrogen feed pipe 30, a green hydrogen feed preheater 31, a green hydrogen inlet pipe I 32, a first-stage green hydrogen inlet branch, and an intermediate-stage green hydrogen inlet branch, the intermediate-stage green hydrogen inlet branch including a second-stage green hydrogen inlet branch and a third-stage green hydrogen inlet branch; the green hydrogen feed pipe 30 is connected to the green hydrogen feed assembly. The inlet of the hydrogen feed preheater 31 is connected; the outlet of the green hydrogen feed preheater 31 is connected to the green hydrogen inlet pipe I 32; the green hydrogen inlet pipe I 32 is connected to the first-stage green hydrogen inlet branch, the second-stage green hydrogen inlet branch, and the third-stage green hydrogen inlet branch respectively; the first-stage green hydrogen inlet branch is connected to the inlet of the first-stage methanation reactor 5; the second-stage green hydrogen inlet branch is connected to the inlet of the second-stage methanation reactor 10; and the third-stage green hydrogen inlet branch is connected to the inlet of the third-stage methanation reactor 15.
[0038] Green hydrogen inlet pipe I 32, green hydrogen inlet pipe II 33, and green hydrogen inlet pipe III 34 are connected in sequence.
[0039] The raw material green hydrogen is divided into three streams through the green hydrogen feed pipe 30, and then connected to the inlet of the first-stage methanation reactor 5, the second-stage methanation reactor 10, and the third-stage methanation reactor 15 via the green hydrogen staged feed pipe I 35, the green hydrogen staged feed pipe II 38, and the green hydrogen staged feed pipe III 41, respectively.
[0040] The first-stage green hydrogen inlet branch includes a green hydrogen staged feed pipe I35 and a green hydrogen delivery pipe I36. The green hydrogen staged feed pipe I35 is connected to the green hydrogen delivery pipe I36. The green hydrogen staged feed pipe I35 is connected to the green hydrogen inlet pipe I32. The green hydrogen delivery pipe I36 is connected to the inlet of the first-stage methanation reactor 5.
[0041] The second-stage green hydrogen inlet branch includes a green hydrogen staged feed pipe II38 and a green hydrogen delivery pipe II39. The green hydrogen staged feed pipe II38 is connected to the green hydrogen delivery pipe II39. The green hydrogen staged feed pipe II38 is connected to the green hydrogen inlet pipe I32 through the green hydrogen inlet pipe II33. The green hydrogen delivery pipe II39 is connected to the inlet of the second-stage methanation reactor 10.
[0042] The third-stage green hydrogen inlet branch includes a green hydrogen staged feed pipe III41 and a green hydrogen delivery pipe III42, with the green hydrogen staged feed pipe III41 connected to the green hydrogen delivery pipe III42; the green hydrogen staged feed pipe III41 is connected to the green hydrogen inlet pipe I32 via green hydrogen inlet pipe II33 and green hydrogen inlet pipe III34 connected in sequence; and the green hydrogen delivery pipe III42 is connected to the inlet of the third-stage methanation reactor 15.
[0043] The steam inlet assembly is used to introduce steam; the steam inlet assembly is connected to the inlet of the first-stage methanation reactor 5; the steam inlet assembly includes a steam feed pipe 45 and a steam delivery pipe 46; the steam feed pipe 45 is connected to the steam delivery pipe 46, and the steam delivery pipe 46 is connected to the inlet of the first-stage methanation reactor 5.
[0044] The inlet of the first-stage methanation reactor 5 is connected to the first-stage feed collection pipe 4, and the green hydrogen transport pipe I 36, CO2 preheating pipe 3, and steam transport pipe 46 converge into the first-stage feed collection pipe 4.
[0045] The outlet of the first-stage methanation reactor 5 is connected to the inlet of the intermediate-stage methanation reactor; the outlet of the intermediate-stage methanation reactor is connected to the inlet of the gas-liquid separator I 19; the gas phase outlet of the gas-liquid separator I 19 is connected to the inlet of the final-stage isothermal methanation reactor 23; the outlet of the final-stage isothermal methanation reactor 23 is connected to the inlet of the gas-liquid separator II 27; the gas phase outlet of the gas-liquid separator II 27 is used to obtain the product green methane.
[0046] The first-stage methanation reactor 5, the first-stage intercooler 7, the second-stage methanation reactor 10, the second-stage intercooler 12, the third-stage methanation reactor 15, and the third-stage intercooler 17 are connected in series via inlet and outlet pipes.
[0047] The outlet of the first-stage methanation reactor 5 and the inlet of the second-stage methanation reactor 10 are connected in sequence via the first-stage methanation reactor bottom discharge pipe 6, the first-stage intercooler 7, the first-stage methanation conveying pipe 8, and the second-stage feed collection pipe 9. The green hydrogen conveying pipe II 39 is connected to the second-stage feed collection pipe 9.
[0048] The outlet of the second-stage methanation reactor 10 and the inlet of the third-stage methanation reactor 15 are connected in sequence via the bottom discharge pipe 11 of the second-stage methanation reactor, the second-stage intercooler 12, the second-stage methanation conveying pipe 13, and the third-stage feed collection pipe 14. The green hydrogen conveying pipe Ⅲ39 is connected to the third-stage feed collection pipe 14.
[0049] The outlet of the third-stage methanation reactor 15 is connected to the inlet of the gas-liquid separator I 19 via the third-stage methanation reactor bottom discharge pipe 16, the third-stage intercooler 17, and the third-stage methanation conveying pipe 18, which are connected in sequence.
[0050] Condensate is discharged from the liquid phase outlet I44 of the gas-liquid separator I19.
[0051] The gas phase outlet of the gas-liquid separator I19 is connected to the inlet of the final isothermal methanation reactor 23 via a gas phase outlet pipe I20, a final isothermal methanation reactor feed preheater 21, and a gas phase conveying pipe I22 connected in sequence.
[0052] The outlet of the final stage isothermal methanation reactor 23 and the inlet of the gas-liquid separator II 27 are connected in sequence by the bottom discharge pipe 24 of the final stage isothermal methanation reactor, the product cooler 25, and the final stage methanation conveying pipe 26.
[0053] The outlet gas of the product cooler 25 is connected to the gas-liquid separator II 27. Part of the condensate is removed in the gas-liquid separator II 27, and the liquid phase outlet II 29 of the gas-liquid separator II 27 discharges the condensate.
[0054] The gas-liquid separator II27 is connected to a gas-phase outlet pipe II28 for obtaining the product green methane.
[0055] The non-circulating green methane production system also includes a cooling unit; the cooling unit is connected to the final isothermal methanation reactor 23.
[0056] The cooling unit includes a steam drum 49, a boiler water inlet pipe 48, a steam outlet pipe 51, and a steam discharge pipe 52.
[0057] The steam drum 49 is connected to the shell side of the final-stage isothermal methanation reactor 23 via heat exchange pipes I 53 and II 54, forming a heat exchange loop; the outlet of the steam drum 49 is connected to the inlet of the shell side of the final-stage isothermal methanation reactor 23 via heat exchange pipe I 53, and the inlet of the steam drum 49 is connected to the outlet of the shell side of the final-stage isothermal methanation reactor 23 via heat exchange pipe II 54.
[0058] The boiler water inlet pipe 48 is connected to the steam drum 49; the outlet of the steam drum 49 is connected to the steam outlet pipe 51, and the steam discharge pipe 52 is connected to the steam drum 49 through the steam outlet pipe 51; the boiler water inlet pipe 48 is used to introduce boiler water into the steam drum 49; the steam discharge pipe 52 is used to discharge steam from the steam drum 49.
[0059] Example 2
[0060] like Figure 1 As shown, this embodiment provides a production system for the non-recycling preparation of green methane. Based on Embodiment 1, this embodiment further includes the following settings:
[0061] The green hydrogen staged feed pipeline I 35, green hydrogen staged feed pipeline II 38, and green hydrogen staged feed pipeline III 41 are equipped with flow control interlocks, which control the green hydrogen feed flow rate in stages and control the reaction progress in each stage of the methanation reactor.
[0062] Green hydrogen flow control devices are installed on the first-stage green hydrogen inlet branch, the second-stage green hydrogen inlet branch, and the third-stage green hydrogen inlet branch. The green hydrogen flow control devices are used to control the green hydrogen feed flow rate in stages and to control the reaction progress in the first-stage methanation reactor 5, the second-stage methanation reactor 10, and the third-stage methanation reactor 15.
[0063] A green hydrogen flow control device I37 is provided between the green hydrogen staged feed pipeline I35 and the green hydrogen delivery pipeline I36. The green hydrogen flow control device I37 includes a first valve and a first flow meter. The first valve is located between the green hydrogen staged feed pipeline I35 and the green hydrogen delivery pipeline I36. The first flow meter is connected to the green hydrogen staged feed pipeline I35, and the green hydrogen staged feed pipeline I35 is the measuring point location of the first flow meter, used to detect the flow rate of the green hydrogen staged feed pipeline I35. The opening degree of the first valve is adjusted according to the flow rate of the green hydrogen staged feed pipeline I35 detected by the first flow meter.
[0064] A green hydrogen flow control device II40 is installed between the green hydrogen staged feed pipeline II38 and the green hydrogen delivery pipeline II39. The green hydrogen flow control device II40 includes a second valve and a second flow meter. The second valve is located between the green hydrogen staged feed pipeline II38 and the green hydrogen delivery pipeline II39. The second flow meter is connected to the green hydrogen staged feed pipeline II38, which is the measuring point of the second flow meter, and is used to detect the flow rate of the green hydrogen staged feed pipeline II38. The opening of the second valve is adjusted according to the flow rate of the green hydrogen staged feed pipeline II38 detected by the second flow meter.
[0065] A green hydrogen flow control device III43 is installed between the green hydrogen staged feed pipeline III41 and the green hydrogen delivery pipeline III42. The green hydrogen flow control device III43 includes a third valve and a third flow meter. The second valve is located between the green hydrogen staged feed pipeline III41 and the green hydrogen delivery pipeline III42. The third flow meter is connected to the green hydrogen staged feed pipeline III41, and the green hydrogen staged feed pipeline III42 is the measuring point of the third flow meter, used to detect the flow rate of the green hydrogen staged feed pipeline III41. The opening of the third valve is adjusted according to the flow rate of the green hydrogen staged feed pipeline III41 detected by the third flow meter.
[0066] The steam feed pipe 45 is equipped with a temperature control interlock. In the three-stage methanation reactors connected in series, namely the first-stage methanation reactor 5, the second-stage methanation reactor 10, and the third-stage methanation reactor 15, the reaction degree in the first-stage methanation reactor 5 is the largest, and therefore the temperature rises the most drastically. By controlling the flow rate of steam entering the first-stage methanation reactor 5, the temperature rise of the gas exiting the first-stage methanation reactor 5 is maintained, thereby controlling the temperature of the entire methanation reactor within a suitable range.
[0067] The steam inlet assembly also includes a temperature control interlock device 47; the steam feed pipe 45 is connected to the temperature control interlock device 47, which controls the flow rate of steam entering the first-stage methanation reactor 5 and maintains the temperature rise of the outlet gas of the first-stage methanation reactor 5. The temperature control interlock device 47 includes a fourth valve and a temperature detector; the fourth valve is located between the steam feed pipe 45 and the steam delivery pipe 46; the temperature detector is connected to the bottom outlet pipe 6 of the first-stage methanation reactor and is used to detect the temperature of the bottom outlet pipe 6 of the first-stage methanation reactor; the opening degree of the fourth valve is adjusted according to the temperature of the bottom outlet pipe 6 of the first-stage methanation reactor detected by the temperature detector.
[0068] The cooling unit also includes a pressure control device 50; the pressure control device 50 is connected to the steam discharge pipe 52; the pressure control device 50 is used to control the flow rate of steam discharge and maintain the pressure inside the steam drum 49. The pressure control device 50 includes a fifth valve and a pressure detector; the fifth valve is located between the steam outlet pipe 51 and the steam discharge pipe 52; the pressure detector is connected to the steam drum 49 and is used to detect the pressure of the steam drum 49; the opening degree of the fifth valve is adjusted according to the pressure of the steam drum 49 detected by the pressure detector.
[0069] Example 3
[0070] like Figure 1 As shown, this embodiment provides a production system for the non-recycling preparation of green methane. Based on Embodiment 2, this embodiment further includes the following settings:
[0071] The non-cyclic production system for preparing green methane includes a controller, which can be a mainstream microcontroller or a processor based on x86, ARM, or RISC-V architectures.
[0072] The first flow meter is communicatively connected to the controller, and the controller is communicatively connected to the first valve. The controller controls the opening degree of the first valve based on the flow rate of the green hydrogen staged feed pipeline I35 detected by the first flow meter.
[0073] The second flow meter is communicatively connected to the controller, and the controller is communicatively connected to the second valve. The controller controls the opening degree of the second valve based on the flow rate of the green hydrogen staged feed pipeline II38 detected by the second flow meter.
[0074] The third flow meter is communicatively connected to the controller, and the controller is communicatively connected to the third valve. The controller controls the opening degree of the third valve based on the flow rate of the green hydrogen staged feed pipeline Ⅲ41 detected by the third flow meter.
[0075] The temperature detector is communicatively connected to the controller, and the controller is communicatively connected to the fourth valve. The controller controls the opening degree of the fourth valve based on the temperature of the discharge pipe 6 at the bottom of the first-stage methanation reactor detected by the temperature detector.
[0076] The pressure detector is communicatively connected to the controller, and the controller is communicatively connected to the fifth valve. The controller controls the opening degree of the fifth valve based on the pressure of the steam drum 49 detected by the pressure detector.
[0077] This invention, through a non-circulating green methane production system, enables the production of green CO2 and green hydrogen methanation. The progress of each stage of methanation reaction is controlled by the staged addition of green hydrogen, while water vapor is added to the first-stage methanation reactor 5 to control the temperature rise of the overall methanation reaction. The process is simple, easy to control, and reduces investment costs and operating expenses.
[0078] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.
Claims
1. A production system for preparing green methane without recycling, characterized in that, The non-circulating green methane production system includes a CO2 feed assembly, a green hydrogen feed assembly, a steam inlet assembly, a first-stage methanation reactor (5), an intermediate-stage methanation reactor, a gas-liquid separator I (19), a final-stage isothermal methanation reactor (23), and a gas-liquid separator II (27). The CO2 feed assembly is used to introduce raw material CO2; the CO2 feed assembly is connected to the inlet of the first-stage methanation reactor (5); The green hydrogen feed assembly is used to introduce raw material green hydrogen; the green hydrogen feed assembly is connected to the inlet of the first-stage methanation reactor (5) and the intermediate-stage methanation reactor respectively; The steam inlet assembly is used to introduce steam; the steam inlet assembly is connected to the inlet of the first-stage methanation reactor (5); The outlet of the first-stage methanation reactor (5) is connected to the inlet of the intermediate-stage methanation reactor; The outlet of the intermediate methanation reactor is connected to the inlet of the gas-liquid separator I (19); The gas phase outlet of the gas-liquid separator I (19) is connected to the inlet of the final stage isothermal methanation reactor (23); The outlet of the final stage isothermal methanation reactor (23) is connected to the inlet of the gas-liquid separator II (27); The gas phase outlet of the gas-liquid separator II (27) is used to obtain green methane.
2. The production system for preparing green methane without recycling according to claim 1, characterized in that, The intermediate methanation reactor includes a second-stage methanation reactor (10) and a third-stage methanation reactor (15) connected in sequence; The outlet of the first-stage methanation reactor (5) is connected to the inlet of the second-stage methanation reactor (10); The outlet of the third-stage methanation reactor (15) is connected to the inlet of the gas-liquid separator I (19); A cooler is provided between the outlet of the first-stage methanation reactor (5) and the inlet of the second-stage methanation reactor (10); A cooler is provided between the outlet of the second-stage methanation reactor (10) and the inlet of the third-stage methanation reactor (15).
3. The production system for preparing green methane without recycling according to claim 1, characterized in that, A cooler is provided between the outlet of the first-stage methanation reactor (5) and the inlet of the intermediate-stage methanation reactor; A cooler is provided between the outlet of the intermediate methanation reactor and the inlet of the gas-liquid separator I (19); A preheater is provided between the gas phase outlet of the gas-liquid separator I (19) and the inlet of the final isothermal methanation reactor (23); A cooler is provided between the outlet of the final stage isothermal methanation reactor (23) and the inlet of the gas-liquid separator II (27).
4. The production system for preparing green methane without recycling according to claim 1, characterized in that, The CO2 feed assembly includes a CO2 feed pipe (1) and a CO2 feed preheater (2); The CO2 feed pipe (1) is connected to the inlet of the CO2 feed preheater (2); The outlet of the CO2 feed preheater (2) is connected to the inlet of the first-stage methanation reactor (5); The CO2 feed preheater (2) is used to preheat the raw material CO2 from the CO2 feed pipe (1).
5. The production system for preparing green methane without recycling according to claim 1, characterized in that, The green hydrogen feed assembly includes a green hydrogen feed pipe (30), a green hydrogen feed preheater (31), a green hydrogen inlet pipe I (32), a first-stage green hydrogen inlet branch, and an intermediate-stage green hydrogen inlet branch; The green hydrogen feed pipe (30) is connected to the inlet of the green hydrogen feed preheater (31); The outlet of the green hydrogen feed preheater (31) is connected to the green hydrogen inlet pipe I (32); The green hydrogen inlet pipe I (32) is connected to the first-stage green hydrogen inlet branch and the intermediate-stage green hydrogen inlet branch respectively; The first-stage green hydrogen inlet branch is connected to the inlet of the first-stage methanation reactor (5); The intermediate-stage green hydrogen inlet branch is connected to the inlet of the intermediate-stage methanation reactor.
6. The production system for preparing green methane without recycling according to claim 5, characterized in that, Both the first-stage green hydrogen inlet branch and the intermediate-stage green hydrogen inlet branch are equipped with green hydrogen flow control devices. The green hydrogen flow control device is used to control the green hydrogen feed flow rate in stages and to control the reaction progress in the first-stage methanation reactor (5) and the intermediate-stage methanation reactor.
7. The production system for preparing green methane without recycling according to claim 1, characterized in that, The steam inlet assembly includes a steam feed pipe (45); The steam feed pipe (45) is connected to the inlet of the first-stage methanation reactor (5).
8. The production system for preparing green methane without recycling according to claim 7, characterized in that, The steam inlet assembly also includes a temperature control interlock device (47); The steam feed pipe (45) is connected to the temperature control interlock device (47), which is used to control the flow rate of steam entering the first-stage methanation reactor (5) and maintain the temperature rise of the gas at the outlet of the first-stage methanation reactor (5).
9. The production system for preparing green methane without recycling according to claim 1, characterized in that, The non-recycle-based green methane production system also includes a cooling unit; The cooling unit is connected to the final stage isothermal methanation reactor (23); The cooling unit includes a steam drum (49), a boiler water inlet pipe (48), and a steam outlet pipe (52); The steam drum (49) is connected to the final isothermal methanation reactor (23) and forms a heat exchange loop; The boiler water inlet pipe (48) and steam outlet pipe (52) are respectively connected to the steam drum (49); The boiler water inlet pipe (48) is used to introduce boiler water into the steam drum (49); The steam discharge pipe (52) is used to discharge water vapor from the steam drum (49).
10. The production system for preparing green methane without recycling according to claim 9, characterized in that, The cooling unit also includes a pressure control device (50); The pressure control device (50) is connected to the steam discharge pipe (52); The pressure control device (50) is used to control the flow rate of steam discharge and maintain the pressure inside the steam drum (49).