Device for extracting water from CO2 methanation reaction and system for preparing water by using CO2 methanation reaction

Abstract

The invention provides a device for extracting water from a CO2 methanation reaction and a system for preparing water by using the CO2 methanation reaction, and belongs to the technical field of CO2 methanation. The device for extracting the water from the CO2 methanation reaction comprises a reaction assembly which is provided with a reaction cavity, and the interior of the reaction cavity is suitable for carrying out the CO2 methanation reaction; the water absorption assembly comprises a water absorption section which is arranged in the reaction cavity and is suitable for absorbing at least one part of water generated by the CO2 methanation reaction; and the drainage section is communicated with the water absorption section and is suitable for draining the water collected by the water absorption section out of the reaction assembly.

Description

Technical Field

[0001] The present invention belongs to the technical field of CO2 methanation, and in particular relates to a device for extracting water from a CO2 methanation reaction and a system for preparing water by utilizing the CO2 methanation reaction. Background Art

[0002] The main problem facing space travel today is the difficulty in carrying and transporting water and energy during the voyage. CO2 methanation provides a solution to this problem. The CO2 in this reaction comes from human metabolism, and H2 is a byproduct of electrolysis of water to produce O2. The water in the product can be used for drinking or electrolysis of water to produce O2, and methane can be used as spacecraft fuel. In practical applications, water and other gases need to be separated, which can facilitate the subsequent use of water on the one hand, and reduce the inhibition of water on the catalytic activity of catalysts on the other hand. At present, gas-liquid separation on Earth can be achieved by gravity sedimentation, but this method is not efficient under microgravity conditions. Therefore, in space stations, water and gas are usually separated by centrifugation. However, this method will cause certain energy consumption and noise pollution. Therefore, simplifying the CO2 methanation separation system to achieve lower energy consumption and higher water recovery efficiency while improving the catalytic activity of the catalyst is a huge challenge in the current space travel process. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a device and system for extracting water from a CO2 methanation reaction, in order to at least partially solve the above technical problems. The specific technical solutions provided by the present invention are as follows.

[0004] As a first aspect of the present invention, a device for extracting water from a CO2 methanation reaction is provided, comprising: a reaction component, provided with a reaction chamber, the reaction chamber being suitable for carrying out a CO2 methanation reaction; and a water absorption component, comprising: a water absorption section, provided in the reaction chamber, suitable for absorbing at least a portion of the water produced by the CO2 methanation reaction; and a drainage section, connected to the water absorption section, suitable for discharging the water collected by the water absorption section to the outside of the reaction component.

[0005] As a second aspect of the present invention, a system for preparing water by utilizing a CO2 methanation reaction is provided, comprising: the above-mentioned device, which is suitable for carrying out a CO2 methanation reaction and extracting at least a portion of the water produced by the CO2 methanation reaction; a heating component, wherein the above-mentioned device is placed inside the heating component and heats the above-mentioned device; a gas supply unit, which is connected to the above-mentioned device and is suitable for providing raw gas for the CO2 methanation reaction; a gas collection component, which is connected to the above-mentioned device and is suitable for collecting the gas discharged by the above-mentioned device and performing component detection; and a water collection component, which is connected to the above-mentioned device and is suitable for collecting water discharged by the above-mentioned device.

[0006] Based on the above technical solution, the device and system for extracting water from CO2 methanation reaction provided by the present invention have at least one of the following beneficial effects.

[0007] (1) In an embodiment of the present invention, in addition to methane, byproduct water is also produced during the CO2 methanation reaction in the reaction chamber of the reaction component. Therefore, the water absorption section of the water absorption component is arranged in the reaction chamber to absorb the produced byproduct water, and discharge the water out of the reaction component through the water discharge section of the water absorption component, so as to achieve the separation of water and gas in the device. The present invention provides a device for extracting water from a CO2 methanation reaction, which can separate the water produced by the CO2 methanation reaction from the reaction position to reduce the inhibition of the catalytic activity of the catalyst of the CO2 methanation reaction. At the same time, the separated water can be used for drinking or other purposes such as electrolysis of water to produce O2, thereby improving resource utilization and CO2 methanation efficiency and reducing energy consumption.

[0008] (2) In an embodiment of the present invention, the device for extracting water from the CO2 methanation reaction provided above is connected to a heating component, a gas supply unit, a gas collection component, and a water collection component, and the gas supply unit provides raw gas to the device above. Under the heating condition of the heating component, the device above performs a CO2 methanation reaction, and the gas generated is collected by the gas collection component, and the water separated by the water absorption component of the device above is collected by the water collection component. The system for preparing water by using the CO2 methanation reaction provided by the present invention collects the water generated by the CO2 methanation reaction, which can be used for drinking or other purposes such as electrolysis of water to produce O2. At the same time, it can improve the efficiency of CO2 methanation, further effectively increase the output of methane, and realize the resource utilization of carbon. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of a device for extracting water from a CO2 methanation reaction in an embodiment of the present invention;

[0010] Figure 2 Schematic diagram of a system for preparing water by using CO2 methanation reaction in an embodiment of the present invention;

[0011] Figure 3 is an X-ray diffraction (XRD) diagram of the NaA molecular sieve seed in Example 1 of the present invention;

[0012] Figure 4 This is a scanning electron microscope (SEM) image of the NaA molecular sieve seed in Example 1 of the present invention;

[0013] Figure 5 is an X-ray diffraction (XRD) diagram of the alumina tube loaded with the NaA molecular sieve membrane in Example 1 of the present invention;

[0014] Figure 6This is a scanning electron microscope (SEM) image of the surface of the NaA molecular sieve membrane in Example 1 of the present invention;

[0015] Figure 7 is a scanning electron microscope (SEM) image of a cross section of a NaA molecular sieve membrane in Example 1 of the present invention;

[0016] Figure 8 This is a scanning diagram of the Al element of the NaA molecular sieve membrane in Example 1 of the present invention;

[0017] Fig. 9 This is a Si element scanning diagram of the NaA molecular sieve membrane in Example 1 of the present invention;

[0018] Fig.10 This is a scanning diagram of the Na element of the NaA molecular sieve membrane in Example 1 of the present invention;

[0019] Fig.11 This is a graph showing the water contact angle test results of the alumina tube loaded with the NaA molecular sieve membrane in Example 1 of the present invention;

[0020] Fig.12 This is a graph showing the water contact angle test results of the alumina tube in Example 1 of the present invention;

[0021] Fig.13 is a schematic diagram of a water absorbing component in Example 1 of the present invention;

[0022] Fig.14 Schematic diagram of a quartz reaction tube in Example 1 of the present invention;

[0023] Fig.15 This is a graph showing the CO2 methanation conversion rate changing with temperature in Example 1 of the present invention.

[0024] Symbols and markings:

[0025] 100: Device for extracting water from CO2 methanation reaction;

[0026] 1: reaction component; 11: reaction chamber; 12: air inlet; 13: exhaust port; 14: water inlet;

[0027] 2: water absorption component; 21: water absorption section; 22: drainage section;

[0028] 200: heating component;

[0029] 300: air supply unit;

[0030] 400: Gas collection component;

[0031] 500: water collection component;

[0032] 600: Control components. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0034] In order to solve the problem that the water produced by the CO2 methanation reaction is difficult to separate during the current space navigation, the present invention provides a device and system for extracting water from the CO2 methanation reaction, wherein the water absorption section of the water absorption component is arranged in the reaction chamber, the byproduct water produced is absorbed, and the water is discharged out of the reaction component through the drainage section of the water absorption component. The device can carry out the CO2 methanation reaction and extract the water generated in the reaction, so that the water is separated from the catalyst surface and discharged from the reaction component, thereby realizing the separation of water and gas in the reaction chamber. The advantage of the device is that while satisfying the gas-liquid separation to obtain a large amount of pure water, it can also improve the catalytic activity of the catalyst. In summary, the present invention may become a powerful experimental device for separating water and improving the catalytic activity of CO2 methanation.

[0035] Figure 1 Schematic diagram of a device for extracting water from a CO2 methanation reaction in an embodiment of the present invention.

[0036] As a first aspect of the present invention, Figure 1 As shown, a device 100 for extracting water from a CO2 methanation reaction is provided, comprising: a reaction component 1, provided with a reaction chamber 11, wherein the reaction chamber 11 is suitable for carrying out a CO2 methanation reaction; and a water absorption component 2, comprising: a water absorption section 21, provided in the reaction chamber 11, suitable for absorbing at least a portion of the water produced by the CO2 methanation reaction; and a drainage section 22, connected to the water absorption section 21, suitable for discharging the water collected by the water absorption section 21 to the outside of the reaction component 1.

[0037] In an embodiment of the present invention, in addition to methane, byproduct water is also produced during the CO2 methanation reaction in the reaction chamber 11 of the reaction component 1. Therefore, the water absorption section 21 of the water absorption component 2 is arranged in the reaction chamber 11 to absorb the produced byproduct water, and discharge it out of the reaction component 1 through the drainage section 22 of the water absorption component 2, so as to achieve the separation of water and gas in the device. The present invention provides a device for extracting water from a CO2 methanation reaction, which can separate the water produced by the CO2 methanation reaction from the reaction position to reduce the inhibition of the catalytic activity of the catalyst of the CO2 methanation reaction. At the same time, the separated water can be used for drinking or other purposes such as electrolyzing water to produce O2, thereby improving resource utilization and CO2 methanation efficiency and reducing energy consumption.

[0038] According to an embodiment of the present invention, the water absorption section 21 includes: a water absorption membrane, which is suitable for selectively passing at least a portion of the water produced by the CO2 methanation reaction; and a porous support tube, which is wrapped by the water absorption membrane and is suitable for collecting the water that selectively passes through the water absorption membrane in the porous support tube and transferring it to the drainage section. The water absorption membrane can selectively pass water to block the gas in the reaction chamber 11 from the outside, and the water that selectively passes further enters the porous support tube and is discharged from the reaction component 1. Furthermore, the water absorption membrane is a molecular sieve membrane made of any one of NaA molecular sieve, KA molecular sieve, and CaA molecular sieve. It should be understood that other materials that can withstand high temperatures and can selectively pass water can also be selected, and the present invention is not limited to this.

[0039] According to an embodiment of the present invention, one end of the porous support tube is connected to the drainage section 22, and the other end is sealed so that the water selectively passing through the water-absorbing membrane is transferred to the drainage section 22 along the opening direction of the porous support tube. One end of the porous support tube is adaptively sealed and connected to the drainage section 22 to avoid the loss of water and the entry of gas in the reaction chamber 11, and the other end is sealed, for example, by a temperature-resistant glue to prevent the loss of water and gas. Further, the porous support tube includes any one of a porous alumina tube, a porous silica tube, a porous magnesium oxide tube, a porous mullite tube, and a porous silicon carbide tube. It should be understood that the porous support tube is used to load the water-absorbing membrane, and at the same time, the water selectively passing through the water-absorbing membrane is moved from the outside of the porous support tube through the tube wall to the inside of the porous support tube and transferred to the drainage section of the water-absorbing component through the tube wall. Therefore, other porous tubular materials that can withstand high temperatures and allow water to pass from the outside of the tube to the inside of the tube can also be selected, and the present invention is not limited to this.

[0040] According to an embodiment of the present invention, the drainage section 22 is a dense tubular structure, one end of which is connected to the water absorption section 21 in the reaction chamber 11, and the other end extends out of the reaction assembly 1. As described above, one end of the drainage section 22 is sealed and connected to one end of the porous support tube, and the other end extends out of the reaction assembly 1 to discharge the water absorbed by the water absorption section 21. Therefore, the material of the drainage section is a dense material to prevent the loss of water inside the drainage section or the inflow of gas inside the reaction chamber. For example, the drainage section can be made of a stainless steel pipe.

[0041] Here, a method for preparing a water absorption component 2 is provided as an example: providing a molecular sieve seed and a porous support tube, and loading the molecular sieve seed on the outside of the porous support tube; mixing a silicon source, an aluminum source, an alkali source and water and stirring them evenly to obtain a molecular sieve membrane growth solution; immersing the porous support tube loaded with the molecular sieve seed in the molecular sieve membrane growth solution for hydrothermal crystallization to obtain a water absorption component 2.

[0042] According to an embodiment of the present invention, the reaction component 1 is further provided with: an air inlet 12, which is connected to the reaction chamber 11 and is suitable for passing the raw material gas into the reaction chamber 11; an exhaust port 13, which is connected to the reaction chamber 11 and is suitable for discharging the gas in the reaction chamber 11; and a water guide port 14, which is connected to the reaction chamber 11 and is suitable for extending the drainage section 22 out of the reaction chamber 11. When the drainage section 22 of the water absorption component 2 extends out of the reaction component 1 through the water guide port 14 on the reaction component 1, the gap between the drainage section 22 and the water guide port 14 is sealed to prevent the gas in the reaction chamber 11 from flowing out from the gap between the drainage section 22 and the water guide port 14.

[0043] According to an embodiment of the present invention, the reaction chamber 11 is filled with a catalyst mixture, and the water absorption section 21 extends into the catalyst mixture. The catalyst mixture includes a CO2 methanation catalyst and a diluent, and the CO2 methanation catalyst can select a commonly used catalyst that catalyzes the conversion of CO2 into methane. Since the CO2 methanation reaction is an exothermic reaction, the CO2 methanation catalyst is diluted by a diluent to neutralize the reaction heat and play a role in heat dissipation. The diluent can be selected from quartz sand, silicon carbide, diatomaceous earth, or other inert materials that can dissipate heat and are resistant to high temperatures. The mass ratio of the CO2 methanation catalyst to the diluent is 1:1.2-1.5. The filling height of the catalyst mixture in the reaction chamber 11 should be appropriately smaller than the length of the water absorption section 21 to achieve the best water absorption effect.

[0044] Since the aircraft is in microgravity during space travel, the traditional gravity-driven fluid flow mode is no longer applicable when using CO2 methanation to prepare water. Water and gas are usually separated by centrifugation, which will cause certain energy consumption and noise pollution. Therefore, based on the above-mentioned device for extracting water from CO2 methanation, the present invention provides a system for preparing water using CO2 methanation, which can be used to prepare methane and water in aviation processes. Methane can be used as spacecraft fuel, and water can be used for drinking or electrolysis to produce O2.

[0045] Figure 2 Schematic diagram of a system for preparing water by using CO2 methanation reaction in an embodiment of the present invention.

[0046] As a second aspect of the present invention, Figure 2As shown, a system for preparing water by using CO2 methanation reaction is provided, comprising: the above-mentioned device 100, which is suitable for performing CO2 methanation reaction and extracting at least a part of water produced by the CO2 methanation reaction; a heating component 200, wherein the above-mentioned device 100 is placed inside the heating component 200 and heats the above-mentioned device 100; a gas supply unit 300, which is connected to the above-mentioned device 100 and is suitable for providing raw gas for the CO2 methanation reaction; a gas collection component 400, which is connected to the above-mentioned device 100 and is suitable for collecting the gas discharged from the above-mentioned device 100 and performing component detection; and a water collection component 500, which is connected to the above-mentioned device 100 and is suitable for collecting water discharged from the above-mentioned device 100.

[0047] In an embodiment of the present invention, the device 100 for extracting water from the CO2 methanation reaction provided above is connected to the heating component 200, the gas supply unit 300, the gas collection component 400, and the water collection component 500, and the raw gas is provided to the device 100 through the gas supply unit 300. Under the heating condition of the heating component 200, the device 100 performs the CO2 methanation reaction, and the generated gas is collected by the gas collection component 400, and the water separated by the water absorption component 2 of the device 100 is collected by the water collection component 500. The system for preparing water by using the CO2 methanation reaction provided by the present invention collects the water generated by the CO2 methanation reaction, which can be used for drinking or other purposes such as electrolysis of water to produce O2, and at the same time can improve the efficiency of CO2 methanation, further effectively increase the output of methane, and realize the resource utilization of carbon.

[0048] According to an embodiment of the present invention, a control component 600 is provided on the path connecting the gas supply unit 300 and the device 100 to adjust the flow rate of the raw material gas entering the device 100 .

[0049] In an embodiment of the present invention, the gas supply unit 300 is connected to the gas inlet 12 of the above-mentioned device 100, the gas collection component 400 is connected to the exhaust port 13 of the above-mentioned device 100, and the water collection component 500 is connected to the drainage section 22 of the above-mentioned device 100 extending out of the water guide port 14. During the CO2 methanation reaction, the heating component 200 heats the above-mentioned device to 150-450°C to provide the temperature required for the CO2 methanation reaction; the flow rate of the raw gas entering from the gas inlet 12 is adjusted by the control component 600 to be greater than the gas flow rate discharged from the exhaust port 13, so as to control the pressure in the reaction chamber 11 to 0.003-0.013MPa; since the above-mentioned device 100 is heated during the CO2 methanation reaction, the water absorbed in the water absorption component 2 is in the state of water vapor, and the water vapor is discharged along the exhaust section 22, and condenses into liquid water after being discharged from the heating component 200. The raw gas provided by the gas supply unit 200 includes H2, CO2 and inert gas, wherein the volume ratio of H2 to CO2 is 4:1. The inert gas acts as an internal standard gas, and its volume fraction in the raw gas is less than 25.0 vol%. Exemplarily, the gas supply unit 300 may select a gas cylinder filled with H2, CO2, or N2; the gas collection component 400 may select an empty gas cylinder or air bag; the water collection component 500 may select a sealed container to prevent water from floating out under microgravity conditions; the heating component 200 may select a heating furnace or other devices that can be used for heating; and the control component 600 may select a gas flow meter.

[0050] The present invention is further described below by examples and related test experiments. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is obvious that one or more embodiments may also be implemented without these specific details. And, in the absence of conflict, the details in the following embodiments may be combined into other feasible embodiments at will. All instruments, consumables and reagents in the following examples, if not otherwise specified, may be obtained from commercial sources.

[0051] Example 1

[0052] In this embodiment 1, a system for preparing water by using CO2 methanation reaction is provided. Figure 2 As shown, its catalytic performance was tested.

[0053] The water absorption section of the water absorption component of the device for extracting water from the CO2 methanation reaction is obtained by the following preparation method.

[0054] (1) Synthesis of NaA molecular sieve seeds.

[0055] NaA molecular sieve seeds were prepared by hydrothermal synthesis. 0.4g sodium hydroxide, 41.7g tetramethylammonium hydroxide and 6.2g aluminum isopropoxide were dissolved in 76.5g deionized water to prepare a precursor solution, which was stirred at 900rpm for 12h at room temperature. Then 18.7g colloidal silica was added dropwise to the above precursor solution and stirred for 12h until a clear solution was formed. The obtained solution was transferred to a stainless steel reactor and hydrothermally synthesized at 100°C for 10h. The reactor was then cooled to room temperature, centrifuged at 8000rpm for 30min and the solid was recovered. The obtained NaA molecular sieve seeds were washed with deionized water to a pH of 9 and finally dried at 100°C for 12h.

[0056] Figure 3 is an X-ray diffraction (XRD) diagram of the NaA molecular sieve seed in Example 1 of the present invention; Figure 4 This is a scanning electron microscope (SEM) image of the NaA molecular sieve seed in Example 1 of the present invention.

[0057] from Figure 3 and Figure 4 It can be seen that the diffraction peaks of the synthesized samples are consistent with the PDF standard card (39-0223), indicating that the NaA molecular sieve seeds are successfully synthesized and the particle size range of the prepared NaA molecular sieve seeds is 50-200 nm.

[0058] (2) Synthesis of NaA molecular sieve water-absorbing membrane.

[0059] (2-1) Introduction of NaA seeds.

[0060] The NaA molecular sieve seeds were fixed on the outer surface of the hollow alumina tube to promote the synthesis of the membrane. Before fixing the molecular sieve seeds, the alumina tube (5 cm long) was cleaned with an ultrasonic cleaner to remove impurities on the inner and outer surfaces, and then both ends of the alumina tube were sealed with polytetrafluoroethylene to prevent the NaA molecular sieve seeds from adhering to the inner surface. First, 0.3 g of NaA molecular sieve seeds were mixed with 30 mL of deionized water and ultrasonicated for 20 min to obtain a 1 wt% NaA molecular sieve seed suspension. The hollow alumina tube was preheated at 120 ° C for 3 h and then soaked in the NaA molecular sieve seed suspension by hot dipping for 20 seconds. After that, the alumina tube was slowly removed from the suspension and heated in an oven at 100 ° C for 1 h to promote the adhesion of the NaA molecular sieve seeds. The above process was repeated three times. Finally. The alumina tube loaded with NaA molecular sieve seeds was moved into an oven at 180 ° C overnight. Before membrane synthesis, the alumina tube loaded with NaA molecular sieve seeds was allowed to cool naturally to room temperature.

[0061] (2-2) Synthesis of water-absorbing film.

[0062] First, 11.0g of sodium hydroxide, 0.2g of sodium aluminate, 0.2g of sodium oxide, 0.2g of alumina and 3.1g of colloidal silica were dissolved in 52g of deionized water to prepare a molecular sieve membrane growth solution with a molar composition of 1Al2O3:5SiO2:50Na2O:1000H2O. The molecular sieve membrane growth solution was vigorously stirred at room temperature for 12h, and then aged for 6h before being transferred to a reactor. Then, an alumina tube loaded with NaA molecular sieve seeds sealed at both ends by polytetrafluoroethylene was placed vertically into the molecular sieve membrane growth solution in the reactor and heated at 90°C for 20h. Then, the alumina tube was taken out of the molecular sieve membrane growth solution, rinsed with deionized water, and dried in an oven at 60°C overnight to prepare an alumina tube loaded with NaA molecular sieve membrane.

[0063] Figure 5 is an X-ray diffraction (XRD) diagram of the alumina tube loaded with the NaA molecular sieve membrane in Example 1 of the present invention; Figure 6 This is a scanning electron microscope (SEM) image of the surface of the NaA molecular sieve membrane in Example 1 of the present invention; Figure 7 is a scanning electron microscope (SEM) image of a cross section of a NaA molecular sieve membrane in Example 1 of the present invention; Figure 8 This is a scanning diagram of the Al element of the NaA molecular sieve membrane in Example 1 of the present invention; Fig. 9 This is a Si element scanning diagram of the NaA molecular sieve membrane in Example 1 of the present invention; Fig.10 This is a scanning diagram of the Na element of the NaA molecular sieve membrane in Example 1 of the present invention.

[0064] from Figure 5 It can be seen that the XRD diffraction peaks of the sample prepared in this example are consistent with the diffraction peaks of the standard PDF cards of NaA and alumina, proving that the alumina tube supported by the NaA molecular sieve membrane has been successfully prepared. Figure 6-Figure 10 It can be seen that the NaA molecular sieve membrane is evenly distributed on the surface of the alumina tube, and the Al, Si, and Na elements in the NaA molecular sieve membrane are mainly concentrated on the surface of the alumina tube loaded with the NaA molecular sieve membrane.

[0065] Fig.11 This is a graph showing the water contact angle test results of the alumina tube loaded with the NaA molecular sieve membrane in Example 1 of the present invention; Fig.12 This is a graph showing the water contact angle test results of the alumina tube in Example 1 of the present invention.

[0066] The larger the water contact angle, the better the hydrophobicity of the material; the smaller the water contact angle, the better the water absorption of the material. Fig.11 and Fig.12It can be seen that the alumina tube loaded with NaA molecular sieve membrane prepared in this embodiment has a smaller water contact angle than the alumina tube not loaded with NaA molecular sieve membrane, and thus has a stronger water absorption performance. Therefore, it is easier to absorb the water generated by the reaction and separate it from the reaction site in the CO2 methanation reaction.

[0067] Fig.13 is a schematic diagram of a water absorbing component in Example 1 of the present invention; Fig.14 This is a schematic diagram of the quartz reaction tube in Example 1 of the present invention.

[0068] One end of the NaA molecular sieve membrane-loaded alumina tube was connected to a stainless steel tube (3 mm inner diameter, 6 mm outer diameter, 25 cm long), and the other end was sealed with a heat-resistant glue to obtain a Fig.13 The water-absorbing component shown.

[0069] Assemble the above-mentioned water absorption components into Fig.14 Before the quartz reaction tube shown in FIG. 1 is filled with a catalyst mixture, the quartz reaction tube is filled with a catalyst mixture. Specifically, the catalyst mixture is obtained by the following method: 0.3 g of Ni / ZrO2 catalyst is granulated into 30-40 meshes, and the catalyst is diluted with 1.3 g of quartz sand. The diluted catalyst mixture is then placed in the quartz reaction tube, and the NaA molecular sieve water absorption film alumina tube is deeply inserted into the catalyst mixture inside the quartz reaction tube to obtain the catalyst mixture as shown in FIG. Figure 1 The device for extracting water from the CO2 methanation reaction is shown in FIG. Then, it is connected with the heating component, the gas supply unit, the gas collection component, the water collection component, and the control component to assemble as shown in FIG. Figure 2 The system shown is for producing water using CO2 methanation reaction.

[0070] Before the CO2 methanation reaction, pure hydrogen (flow rate 50 mL / min) was used for in-situ reduction at 450°C for 2 h to reduce the nickel oxide in the catalyst mixture to nickel to improve the methane conversion efficiency, and then cooled to 150°C and maintained at this temperature.

[0071] CO2 methanation reaction: A mixed gas containing 76.0 vol% H2, 19.0 vol% CO2 and 5.0 vol% N2 was passed through the catalyst mixture at a flow rate of 80 mL / min, and the temperature of the heating component was controlled to rise from 150°C to 450°C. Every time the temperature rises by 30°C, a gas chromatograph with TCD and FID is used to detect, collect and analyze the gas composition discharged from the exhaust port. Water vapor is collected at the end of the stainless steel tube connected to the alumina tube loaded with NaA molecular sieve membrane. At the same time, for comparison, CO2 methanation reaction was also carried out in a conventional quartz tube reaction system without a water absorption component installed.

[0072] Fig.15This is a graph showing the CO2 methanation conversion rate changing with temperature in Example 1 of the present invention.

[0073] like Fig.15 As shown, compared with the system without the water absorption component installed, the system with the water absorption component installed can transfer the water produced by the methanation reaction at the catalyst bed in time, so that the catalyst is less affected by water and the metal agglomeration and catalyst deformation on the Ni / ZrO2 catalyst are weakened, thus showing a stronger promoting effect on the Ni / ZrO2-catalyzed CO2 methanation.

[0074] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for extracting water from CO2 methanation reaction, characterized in that: include: A reaction assembly is provided with a reaction chamber, wherein the reaction chamber is suitable for performing a CO2 methanation reaction; as well as Water absorption assembly, comprising: a water absorption section, disposed in the reaction chamber and adapted to absorb at least a portion of water produced by the CO2 methanation reaction; as well as The drainage section is connected to the water absorption section and is suitable for discharging the water collected by the water absorption section to the outside of the reaction component.

2. The device according to claim 1, characterized in that The water absorption section comprises: a water absorbing membrane adapted to selectively pass at least a portion of the water produced by the CO2 methanation reaction; and The porous support tube is wrapped by the water-absorbing membrane and is suitable for collecting the water selectively passing through the water-absorbing membrane in the porous support tube and transferring it to the drainage section.

3. The device according to claim 2, characterized in that The water-absorbing membrane is a molecular sieve membrane made from any one of NaA molecular sieve, KA molecular sieve and CaA molecular sieve.

4. The device according to claim 2, characterized in that One end of the porous support tube is connected to the drainage section, and the other end is sealed, so that water that selectively passes through the water-absorbing membrane is transferred to the drainage section along the opening direction of the porous support tube.

5. The device according to claim 2 or 4, characterized in that: The porous support tube includes any one of a porous alumina tube, a porous silica tube, a porous magnesia tube, a porous mullite tube, and a porous silicon carbide tube.

6. The device according to claim 1, characterized in that The drainage section is a dense tubular structure, one end of which is connected to the water absorption section in the reaction chamber, and the other end of which extends out of the reaction component.

7. The device according to claim 1, characterized in that The reaction component is also provided with: An air inlet, connected to the reaction chamber, and adapted to pass raw material gas into the reaction chamber; an exhaust port, connected to the reaction chamber and adapted to exhaust the gas in the reaction chamber; and The water guide port is connected to the reaction chamber and is suitable for extending the drainage section out of the reaction chamber.

8. The device according to claim 1 or 7, characterized in that The reaction chamber is filled with a catalyst mixture, and the water absorption section extends into the catalyst mixture.

9. A system for preparing water by using CO2 methanation reaction, characterized in that: include: The device according to any one of claims 1 to 8, suitable for carrying out a CO2 methanation reaction and extracting at least a portion of the water produced by the CO2 methanation reaction; A heating component, wherein the device is placed inside the heating component and the device is heated; a gas supply unit, connected to the device and suitable for providing raw gas for the CO2 methanation reaction; a gas collection assembly, connected to the device, adapted to collect the gas exhausted by the device and perform component detection; and The water collecting assembly is connected with the device and is suitable for collecting water discharged from the device.

10. The system according to claim 9, characterized in that A control component is provided on the path connecting the gas supply unit and the device to adjust the flow rate of the raw material gas entering the device.

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