Ni-based catalyst suitable for low-temperature catalysis of methane water vapor reaction and preparation method and application of Ni-based catalyst

Abstract

The invention discloses a Ni-based catalyst suitable for catalyzing methane steam reaction at low temperature as well as a preparation method and application of the Ni-based catalyst. The preparation method of the catalyst comprises the following steps: modifying a carrier alumina by using a nitrogen-containing organic matter such as urea, melamine or dicyandiamide, loading a nickel salt such as nickel nitrate by using an impregnation method, and drying and roasting to obtain the Ni-based catalyst suitable for low-temperature catalytic methane steam reforming reaction. Compared with an unmodified catalyst, the catalyst disclosed by the invention has the characteristics of high activity, high carbon deposition resistance, long service life and the like when being used for low-temperature methane steam reforming hydrogen production, and has an industrial application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of metal Ni element catalysts, and specifically relates to a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction, and a preparation method and application thereof. Background Art

[0002] As people pay more and more attention to global warming, it is imperative to reduce greenhouse gas emissions in the atmosphere. Carbon dioxide and methane are two common greenhouse gases. In recent years, with the in-depth development of natural gas resources, people have become more and more interested in the research of methane conversion. So far, methane is mainly converted into hydrogen or synthesis gas (CO and H) through steam methane reforming (SRM), dry methane reforming (DRM) and partial oxidation of methane (POM). 2 Hydrogen is an essential green energy for sustainable social development. Synthesis gas can also be further reacted to synthesize methanol or other organic compounds.

[0003] Among various methane conversion strategies, SRM is the main industrial process for producing hydrogen and synthesis gas. It is an endothermic reaction of methane and water vapor under high temperature and low pressure conditions. During this process, the water-gas shift reaction occurs, further promoting the production of hydrogen.

[0004]

[0005] Nickel-based catalysts are commonly used in traditional SRM processes due to their low cost and high activity. However, carbon deposition and sintering are still the main reasons for the deactivation of traditional Ni-based catalysts. 4 It tends to dissociate on the Ni surface to form carbon deposits, thereby covering the active sites of the catalyst, resulting in a rapid decrease in catalyst activity. Therefore, the current research on methane reforming focuses on how to improve the stability of the catalyst. Literature shows that when the size of Ni nanoparticles is controlled at 3-5nm or less, it has better anti-carbon deposition performance. In the process of developing Ni-based catalysts, preparing small-particle-size and highly dispersed Ni-based catalysts is the key to solving the carbon deposition problem in the industrial production of catalysts (Vogt C, Kranenborg J, Monai M, et al. Structure sensitivity in steam and dry methane reforming over nickel: activity and carbon formation [J]. ACS Catalysis, 2019, 10 (2): 1428-1438.). Summary of the invention

[0006] The technical problem to be solved by the present invention is that the active centers of the existing catalysts used in the low-temperature methane steam reforming process are easily sintered, resulting in carbon deposition and deactivation of the catalyst. Therefore, the present invention provides a Ni-based catalyst suitable for low-temperature catalytic methane steam reaction and a preparation method thereof.

[0007] In order to test the above-mentioned purpose, the technical scheme of the present invention is as follows:

[0008] A method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction comprises the following steps.

[0009] 1) Using an equal volume impregnation method, the nitrogen-containing organic matter is fully dissolved in a dispersant to obtain an impregnation solution, the carrier alumina is added to the impregnation solution, ultrasonicated for 20-30 minutes, and then allowed to stand at room temperature for 12-15 hours. After standing, it is dried and then carbonized in a nitrogen atmosphere to obtain a modified γ-Al 2 O 3 ;

[0010] 2) The soluble metal salt of the active component Ni is dissolved in deionized water, and added dropwise to the modified alumina obtained in step 1) by an equal volume impregnation method. After sufficient impregnation, it is dried, calcined, tableted, granulated, and 40-60 mesh particles are screened. After reduction, a Ni-based catalyst modified with nitrogen-containing organic matter is obtained.

[0011] Furthermore, in step 1), the loading amount of the nitrogen-containing organic matter on the carrier alumina is 1%-10%, preferably 3%-5%, and the nitrogen-containing organic matter is urea, melamine or melamine.

[0012] Furthermore, in step 1), the carbonization temperature is 400-800° C., preferably 500-600° C., and the carbonization time is 4-6 h.

[0013] Furthermore, in step 2), the soluble metal salt of the active component Ni is a sulfate, nitrate or chloride salt of nickel, and the metal ion concentration of nickel ions in the aqueous solution is 0.5-3.0 mol·L -1 , preferably 1.2-2.0 mol·L -1 .

[0014] Further, in step 2), the calcination temperature is 500-800°C, preferably 600-650°C, and the calcination time is 4-6h. Further, in step 2), the reducing atmosphere is hydrogen, and the reducing space velocity is 3000-6000h -1 , the reduction temperature is 500-800℃, and the reduction time is 2-5h.

[0015] A Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction prepared by the above-mentioned preparation method.

[0016] An application of a Ni-based catalyst in a low-temperature catalytic reaction of methane and water vapor comprises the following steps: performing a catalytic reaction in a fixed bed reactor, loading the catalyst in the fixed bed reactor, introducing CH 4 and N 2 The mixed gas undergoes a catalytic reaction, with the ratio of methane gas to nitrogen in the mixed gas being 5:1. The other end is injected with deionized water into the heating belt for heating and gasification by using an injection pump. The target product of the low-temperature methane steam reforming reaction is hydrogen. The reaction temperature is 500-700°C, the reaction pressure is 0.1-5.0Mpa, the water-carbon ratio is 2.0-5.0, and the raw gas space velocity is 3000-15000h -1 .

[0017] The beneficial effects of the present invention are:

[0018] 1) The present invention modifies the carrier so that the surface of alumina is covered with a large amount of carbon nitride, which has an in-situ anchoring effect on the impregnated Ni particles, is conducive to the formation of small particles of Ni, and improves the dispersion of Ni on the surface of alumina, thereby improving the conversion rate and stability of the catalyst.

[0019] 2) The methane conversion rate of the present invention is 55-80%. The catalyst prepared by the method has excellent stability and anti-carbon deposition ability, and the preparation process is simple and has high repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the thermogravimetric analysis of the catalyst after 500 hours of reaction.

[0021] Figure 2 This is the XRD data characterization of the catalyst after reduction. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings, but the protection scope of the present invention is not limited to these implementation cases.

[0023] Implementation Case 1

[0024] According to the metal Ni loading of 12%, 0.122g of urea was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; then 5g of γ-Al 2 O 3 Add to the above impregnation solution, ultrasonicate for 20 minutes, place at room temperature for 12 hours, dry at 80 ° C for 6 hours, and then select carbonization treatment in nitrogen atmosphere, calcination at 450 ° C for 4 hours to obtain modified γ-Al2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3 Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in a nitrogen atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0025] Comparative Case 1

[0026] According to the metal Ni loading of 12%, the γ-Al 2 O 3 Without modification: 3.35 g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components. 2 O 3 The mixture was added to the impregnation solution containing the active component, and then ultrasonicated for 20 minutes and allowed to stand at room temperature for 12 hours. After standing, it was dried at 80°C for 6 hours, and then calcined under a nitrogen atmosphere at 600°C for 4 hours. The particles were pressed, granulated, and screened for 40-60 mesh. The particles were placed in a fixed bed reactor for in-situ reduction. The particles were heated at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0027] Comparative Case 2

[0028] According to the metal Ni loading of 12%, the co-impregnation method was adopted: 3.35g Ni(NO 3 ) 2 6H 2 O and 0.122 g of urea were dissolved in 5 g of deionized water to obtain an impregnation solution containing active components. 2 O 3The mixture was added to the impregnation solution containing the active component, ultrasonicated for 20 minutes, and then the impregnation was completed. Then, the mixture was allowed to stand at room temperature for 12 hours. After the standing, the mixture was dried at 80°C for 6 hours. Then, the mixture was calcined in a nitrogen atmosphere at 600°C for 4 hours. The mixture was tableted, granulated, and screened for 40-60 mesh particles. The particles were placed in a fixed bed reactor for in-situ reduction. The mixture was dried at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0029] Implementation Case 2

[0030] According to the metal Ni loading of 12%, the amount of nitrogen-containing organic matter was changed: 0.251g of urea was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; 5g of γ-Al 2 O 3 Add to the above impregnation solution, ultrasonicate for 20 minutes, wait for the impregnation to be complete, then stand at room temperature for 12 hours, dry at 80 ° C for 6 hours, and then choose to carbonize in a nitrogen atmosphere at a carbonization temperature of 450 ° C for 4 hours to obtain the modified γ-Al 2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3 Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in a nitrogen atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0031] Implementation Case 3

[0032] According to the metal Ni loading of 12%, the amount of nitrogen-containing organic matter was changed: 0.502g of urea was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; 5g of γ-Al 2 O 3Add to the above impregnation solution, ultrasonicate for 20 minutes, wait for the impregnation to be complete, then stand at room temperature for 12 hours, dry at 80 ° C for 6 hours, and then choose to carbonize in a nitrogen atmosphere at a carbonization temperature of 450 ° C for 4 hours to obtain the modified γ-Al 2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3 Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in air atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0033] Implementation Case 4

[0034] According to the metal Ni loading of 12%, the type of nitrogen-containing organic matter was changed: 0.144g of melamine was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; 5g of γ-Al 2 O 3 After adding the above impregnation solution to the ultrasonic for 20 minutes, wait for the impregnation to be complete, and then stand at room temperature for 12 hours. After standing, dry at 80 ° C for 6 hours, and then choose to carbonize in a nitrogen atmosphere at a carbonization temperature of 450 ° C for 4 hours to obtain the modified γ-Al 2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3 Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in air atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0035] Implementation Case 5

[0036] According to the metal Ni loading of 12%, the type of nitrogen-containing organic matter was changed: 0.164g of melamine was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; 5g of γ-Al 2 O 3 Add to the above impregnation solution, ultrasonicate for 20 minutes, wait for the impregnation to be complete, then stand at room temperature for 12 hours, dry at 80 ° C for 6 hours, and then choose to carbonize in a nitrogen atmosphere at a carbonization temperature of 450 ° C for 4 hours to obtain the modified γ-Al 2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3 Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in air atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0037] Implementation Case 6

[0038] According to the metal Ni loading of 12%, the carbonization temperature was changed: 0.122g of urea was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; then 5g of γ-Al 2 O 3 Add to the above impregnation solution, ultrasonicate for 20 minutes, wait for the impregnation to be complete, then stand at room temperature for 12 hours, dry at 80 ° C for 6 hours, and then choose to carbonize in a nitrogen atmosphere at a carbonization temperature of 500 ° C for 4 hours to obtain the modified γ-Al 2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in air atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0039] Implementation Case 7

[0040] According to the metal Ni loading of 12%, the carbonization atmosphere was changed: 0.122g of urea was fully dissolved in 5g of deionized water to obtain an organic impregnation solution; then 5g of γ-Al 2 O 3 Add the above impregnation solution, ultrasonicate for 20 minutes, wait for the impregnation to be complete, and then stand at room temperature for 12 hours. After standing, dry at 80 ° C for 6 hours, and then choose to carbonize in an argon atmosphere at a carbonization temperature of 450 ° C for 4 hours to obtain the modified γ-Al 2 O 3 . Then 3.35g Ni(NO 3 ) 2 6H 2 O was fully dissolved in 5 g of deionized water to obtain an impregnation solution containing active components, and then the modified γ-Al 2 O 3 Add to the impregnation solution containing active components, wait for the impregnation to be completed, then stand at room temperature for 12 hours, dry at 80°C for 6 hours, and then choose to roast in air atmosphere at 600°C for 4 hours, press, granulate, screen 40-60 mesh particles, place in a fixed bed reactor for in-situ reduction, and heat at 600°C for 4000 hours. -1 space velocity, and hydrogen was used for reduction for 2 h to obtain a Ni-based catalyst modified with nitrogen-containing organic matter.

[0041] In order to verify the beneficial effects of the present invention, the inventors conducted a low-temperature methane steam reforming reaction performance evaluation on implementation cases 1-7 and comparative cases 1 and 2. The specific experimental results are as follows:

[0042] 1 ml (0.7 g) of catalyst was placed in the isothermal zone of the fixed bed reactor, and a mixture of methane and nitrogen (the volume ratio of methane to nitrogen was 5:1) was introduced under normal pressure. A syringe pump was used to obtain water vapor at the other end. The reaction temperature was 600 °C, the reaction pressure was normal pressure, and the reaction space velocity was 9600 h -1, the water-carbon ratio is 4. Nitrogen is used as the internal standard gas for chromatographic analysis, and the methane, carbon monoxide and carbon dioxide in the gas phase product are quantitatively analyzed by TCD online chromatographic analysis. Finally, the methane conversion rate is calculated, and the test results are listed in Table 1.

[0043] Table 1 Summary of evaluation data on methane steam reforming reaction activity of different catalysts

[0044]

[0045]

[0046] As can be seen from Table 1, the conversion rates of different cases are different. The initial conversion rate of comparative case 1 is 59.17%. After 500 hours of reaction, the methane conversion rate drops to 54.21%. The initial conversion rate of comparative case 2 is 65.81%. After 500 hours of reaction, the methane conversion rate drops to 42.74%. In comparison, the addition of nitrogen-containing organic matter in comparative case 2 is carried out by co-impregnation method, which makes the conversion rate increase to a certain extent, indicating that nitrogen-containing organic matter has a certain effect on the modification of catalyst. The initial conversion rate in implementation case 1 is 68.81%, and after 500 hours of reaction, the methane conversion rate drops to 65.22%. Compared with the further increase in the methane conversion rate in comparative case 2, the present invention has a higher methane conversion rate. The present invention further improves the catalytic activity by changing the order of adding organic matter during the impregnation process. The possible reason is that the carbonization treatment of organic matter impregnation first is conducive to the uniform dispersion of carbon species on the surface, forming more abundant carbide defects, and the abundant carbon species defects further improve the catalytic activity.

[0047] Implementation cases 1, 2, and 3 are single-factor variable experiments on nitrogen-containing organic matter. When the nitrogen content is 1wt%, 2wt%, and 4wt%, respectively, the corresponding methane conversion rates are 68.81%, 71.23%, and 64.73%, respectively. It is not difficult to find that as the amount of nitrogen-containing organic matter doping increases, the methane conversion rate shows a trend of first increasing and then decreasing. The possible reason is that with the increase of nitrogen-containing organic matter, the interaction between organic matter and active components is enhanced, resulting in an increase in methane conversion rate. However, when the organic matter increases excessively, there will be excess nitrogen-containing substances that poison the surface of some metal particles, thereby reducing the active sites and decreasing the activity. Implementation cases 1, 4, and 5 are experiments on the types of nitrogen-containing organic matter. When different nitrogen-containing organic matter is selected for impregnation, the conversion rate is different. According to the current experimental data, the methane conversion performance is best when urea is used for impregnation, which may be related to the molecular structure of urea.

[0048] like Figure 1As shown, after the reaction, the catalyst after the reaction is collected and characterized by thermogravimetry. The horizontal axis is the temperature and the vertical axis is the mass percentage. It can be seen from the figure that the four curves all begin to lose about 2% of their mass at 0-200°C. It is speculated that the lost mass is the moisture adsorbed on the catalyst surface and the impurities in the air. The increase in the mass part at 200-400°C can be explained as the oxidation of the nickel substance. The large-scale mass loss begins at 450°C, which is caused by the combustion reaction of the carbon deposit on the catalyst surface. After that, by calculating the difference between the mass at room temperature and the mass at 800°C, it can be inferred that the carbon deposition of the catalyst during the reaction time is small. The smaller the mass difference, the less carbon on the catalyst surface, and the stronger the anti-carbon deposition ability of the catalyst. It can be seen from the figure that the carbon deposition amount in the implementation case 1 after 500h of reaction is only 14.68%, which is much less than 21.89% in the comparative case 1, proving that the invention is conducive to improving the anti-carbon deposition ability of the catalyst.

[0049] Figure 2 The XRD patterns of catalysts in different cases show that the catalysts in four different cases all show obvious characteristic diffraction peaks of Ni. The average size of Ni crystallites can be estimated by the Scherrer formula. As shown in the figure, the peak with 2theta of 43° is the peak of Ni. Compared with the characteristic peak in comparison case one, the characteristic peak in implementation case one is relatively flat and has a larger half-width. According to the formula, it can be inferred that the implementation case has smaller Ni particles. Therefore, it is not difficult to conclude that after the nitrogen-containing organic matter modifies the alumina, it is beneficial to form small particles of Ni on the surface, which is beneficial to the improvement of dispersion under the premise of the same surface area. At the same time, small-sized active component particles can often expose more active sites, which is beneficial to the improvement of catalytic activity. Therefore, the present invention is a catalyst and preparation method with high dispersion, high activity and excellent anti-carbon deposition performance.

Claims

1. A method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction, characterized in that: The following steps are included. 1) using an equal volume impregnation method, the nitrogen-containing organic matter is fully dissolved in a dispersant to obtain an impregnation solution, the carrier alumina is added to the impregnation solution, ultrasonicated for 20-30 minutes, and then allowed to stand at room temperature for 12-15 hours, dried after standing, and then carbonized in a nitrogen atmosphere to obtain modified γ-Al2O3; 2) The soluble metal salt of the active component Ni is dissolved in deionized water, and added dropwise to the modified alumina obtained in step 1) by an equal volume impregnation method. After sufficient impregnation, it is dried, calcined, tableted, granulated, and 40-60 mesh particles are screened. After reduction, a Ni-based catalyst modified with nitrogen-containing organic matter is obtained.

2. The method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction according to claim 1, characterized in that: In step 1), the loading amount of the nitrogen-containing organic matter on the carrier alumina is 1%-10%, preferably 3%-5%, and the nitrogen-containing organic matter is urea, melamine or melamine.

3. The method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction according to claim 1, characterized in that: In step 1), the carbonization temperature is 400-800° C., preferably 500-600° C., and the carbonization time is 4-6 hours.

4. The method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction according to claim 1, characterized in that: In step 2), the soluble metal salt of the active component Ni is a sulfate, nitrate or chloride salt of nickel, and the metal ion concentration of nickel ions in the aqueous solution is 0.5-3.0 mol·L -1 , preferably 1.2-2.0 mol·L -1 .

5. The method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction according to claim 1, characterized in that: In step 2), the calcination temperature is 500-800° C., preferably 600-650° C., and the calcination time is 4-6 hours.

6. The method for preparing a Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction as claimed in claim 1, characterized in that In step 2), the reducing atmosphere is hydrogen, and the reducing space velocity is 3000-6000h -1 , the reduction temperature is 500-800℃, and the reduction time is 2-5h.

7. A Ni-based catalyst suitable for low-temperature catalytic methane-water vapor reaction prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the Ni-based catalyst as claimed in claim 7 in low-temperature catalytic methane-water vapor reaction, characterized in that: The method comprises the following steps: carrying out a catalytic reaction in a fixed bed reactor, loading a catalyst in the fixed bed reactor, introducing a mixed gas of CH4 and N2 for a catalytic reaction, wherein the ratio of methane gas to nitrogen in the mixed gas is 5:1, and injecting deionized water into a heating belt at the other end for heating and gasification by using an injection pump, wherein the target product of the low-temperature methane steam reforming reaction is hydrogen, the reaction temperature is 500-700°C, the reaction pressure is 0.1-5.0Mpa, the water-carbon ratio is 2.0-5.0, and the raw gas space velocity is 3000-15000h -1 .

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