Process for the preparation of a highly thermally stable methanation catalyst for the methanation of high concentrations of co / co2

Abstract

The application discloses a preparation method of a high-heat-stable methanation catalyst for high-concentration CO / CO2 methanation. A magnesium precursor and an aluminum precursor are added into a solvent to be stirred and dissolved, a solution A is prepared, and water bath heating is carried out; a template agent is added into the solution A to be stirred, and a mixed solution B is prepared; a weak alkaline solution is added dropwise into the mixed solution B until the pH reaches 9-10, and stirring is carried out at the temperature until the solution is completely evaporated; calcination is carried out to obtain a template-containing carrier; an etching liquid is used to etch the template; suction filtration and washing are carried out; and calcination is carried out to obtain a mesoporous magnesium-aluminum spinel carrier. The mesoporous magnesium-aluminum spinel carrier is placed in a flask, a vacuum is drawn, and a solution containing an equal amount of a nickel precursor and an additive precursor is added; drying and calcination are carried out to obtain the high-heat-stable methanation catalyst. The catalyst prepared by the method has good catalytic activity and high heat stability.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically a method for preparing a methanation catalyst. Background Technology

[0002] Natural gas, as a clean energy source, produces less carbon dioxide when burned compared to coal and oil. It also helps reduce emissions of toxic gases such as sulfur dioxide and nitrogen oxides, as well as particulate matter. my country's basic energy situation is characterized by abundant coal, scarce oil, and limited natural gas. The shortage of natural gas necessitates large-scale imports annually, reaching 168 billion cubic meters in 2021 alone. Against the backdrop of current efforts to achieve peak carbon emissions and carbon neutrality, the natural gas industry is poised for significant growth opportunities.

[0003] Natural gas is mainly composed of methane, which can be produced by the catalytic reaction of carbon monoxide and / or carbon dioxide with hydrogen. The large-scale application of methanation can effectively alleviate the shortage of natural gas. At the same time, the carbon consumption of the reaction raw materials also helps to reduce carbon emissions.

[0004] The reaction equations for the methanation of carbon monoxide and / or carbon dioxide with hydrogen are shown below:

[0005] CO + 3H₂ => CH₄ + H₂O △ r H m = -206kJ / mol

[0006] CO2 + 4H2 => CH4 + 2H2O △ r H m = -165kJ / mol

[0007] Both reactions are strongly exothermic. In a catalytic reactor, for every 1% increase in CO in the feed gas, the catalyst bed temperature can rise by 72°C, and for every 1% increase in CO2, the catalyst bed temperature can rise by 60°C. These strongly exothermic reactions can lead to catalyst sintering, severely affecting the catalyst's long-term lifespan. Therefore, in typical methanation reactions, researchers often control the CO and CO2 content in the feed gas to avoid excessive temperature rise in the bed, which is more favorable for the catalyst. However, under these conditions, the methane concentration in the product is limited. When the feed gas contains a large amount of CO and / or CO2, the catalyst bed will face a severe temperature rise problem during the reaction, making the preparation of highly thermally stable methanation catalysts urgent.

[0008] CN104998645B discloses a method for preparing a nickel-based methanation catalyst using cordierite honeycomb ceramic as a support, which can be used for high-concentration carbon monoxide methanation reactions. However, the preparation method of this catalyst is cumbersome and requires three impregnation, drying, and calcination processes, which is time-consuming. CN104475119B discloses a high-temperature CO2 methanation catalyst and its preparation and application methods. This catalyst can be used for high-concentration carbon dioxide methanation reactions and exhibits good activity at high temperatures. However, the low-temperature activity of this catalyst is not disclosed, and its long-term reaction life is also unknown. CN102755894B discloses a titanium-based methanation catalyst, its preparation method, and its application. It is suitable for high-concentration CO and CO2 hydrogenation conversion reactions. The support is a titanium-zirconium composite support, and the active component, nickel oxide, is obtained by heating and decomposing synthetic basic nickel carbonate. The preparation process is relatively cumbersome, requiring the addition of Triathon and polyethylene glycol, and no long-term reaction life test has been conducted. Summary of the Invention

[0009] The purpose of this invention is to solve the above-mentioned technical problems and provide a method for preparing a high-thermal-stable methanation catalyst for high-concentration CO / CO2 methanation. The prepared methanation catalyst has good catalytic performance, low activation temperature, wide applicable temperature range, and exhibits excellent activity and high thermal stability in long-term high-temperature lifetime tests.

[0010] The technical solution discloses a method for preparing a highly thermally stable methanation catalyst for high-concentration CO / CO2 methanation. A magnesium precursor and an aluminum precursor are dissolved in a solvent by stirring to obtain solution A, which is then heated in a water bath. A template agent is added to solution A and stirred to obtain a mixed solution B. A weakly alkaline solution is added dropwise to mixed solution B until the pH reaches 9-10, and the solution is stirred at this temperature until it is completely evaporated. The solution is then calcined to obtain a template agent-containing support. The template is then etched using an etching solution, filtered, washed, and calcined to obtain a mesoporous magnesium-aluminum spinel support. The mesoporous magnesium-aluminum spinel is placed in a flask, vacuumed, and an equal volume of a solution containing a nickel precursor and an auxiliary precursor is added. The solution is then dried and calcined to obtain the highly thermally stable methanation catalyst.

[0011] The molar ratio of magnesium to aluminum in solution A is 1:2, and the molar concentration of magnesium is 0.01-1 mol / L. Too much magnesium will cause magnesium oxide to precipitate, while too little will cause aluminum oxide to precipitate. This will affect the loading of subsequent active metals and additives, and may also lead to side reactions during the reaction process.

[0012] The water bath heating temperature is 40-90℃.

[0013] The template agent is an ordered mesoporous material with a pore size of 3-5 nm.

[0014] The template agent is KIT-6 and / or MCM-41.

[0015] The magnesium precursor is at least one of magnesium nitrate, magnesium oxalate, magnesium sulfate, magnesium chloride, magnesium perchlorate, magnesium ethoxide, magnesium acetate, magnesium citrate, and magnesium acetylacetonate; the aluminum precursor is at least one of aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum isopropoxide, aluminum sec-butoxide, aluminum lactate, aluminum oxalate, and aluminum acetylacetonate. The solvent can be one or more of deionized water, methanol, ethanol, acetonitrile, ethyl acetate, butyl acetate, ethylene glycol, isopropanol, glycerol, acetone, tetrahydrofuran, toluene, dimethyl sulfoxide, N,N-dimethylformamide, 1,2-dichloroethane, chloroform, and cyclohexane; the weakly alkaline solution can be one or more of potassium carbonate solution, sodium carbonate solution, potassium bicarbonate solution, sodium bicarbonate solution, urea solution, and ammonia water, wherein the mass fraction of the solute in the weakly alkaline solution is 0.1%–30%.

[0016] The ratio of the amount of template agent added to the mass of the theoretically generated magnesium aluminum spinel is 1:2 to 2:1 to ensure that the magnesium aluminum spinel can fully occupy the template agent channels. Too much template agent will cause the constructed magnesium aluminum spinel skeleton to be loose and collapse during high-temperature calcination and reaction. Too little template agent will cause some magnesium aluminum spinel to overflow from the template agent channels and form a sintered carrier after calcination.

[0017] Preferably, the nickel-containing precursor is at least one of nickel nitrate, nickel chloride, nickel sulfate, nickel perchlorate, basic nickel carbonate, nickel acetylacetone, nickel acetate, nickel oxalate, and nickel lactate.

[0018] Preferably, the auxiliary precursor is at least one selected from lanthanum precursor, cerium precursor, zirconium precursor, molybdenum precursor, and yttrium precursor. Specifically, the lanthanum precursor is one of lanthanum nitrate, lanthanum chloride, lanthanum sulfate, lanthanum acetate, and lanthanum acetylacetonate; the cerium precursor is one of cerium nitrate, cerium chloride, cerium oxalate, cerium ammonium nitrate, cerium perchlorate, and cerium acetate; the zirconium precursor is one of zirconium nitrate, zirconium oxynitrate, zirconium sulfate, zirconium chloride, zirconium ethoxide, zirconium acetate, and zirconium acetylacetonate; the molybdenum precursor is one of molybdenum chloride, sodium phosphomolybdate, molybdenum acetylacetonate, and molybdenum acetate; and the yttrium precursor is one of yttrium nitrate, yttrium chloride, yttrium sulfate, yttrium isopropoxide, yttrium acetate, and yttrium acetylacetonate.

[0019] The solution containing nickel precursor and auxiliary precursor is obtained by dissolving the nickel precursor and auxiliary precursor in a solvent. The solvent selected for dissolution is one or more of the following: deionized water, methanol, ethanol, acetonitrile, ethyl acetate, butyl acetate, ethylene glycol, isopropanol, glycerol, acetone, tetrahydrofuran, toluene, dimethyl sulfoxide, N,N-dimethylformamide, 1,2-dichloroethane, chloroform, and cyclohexane.

[0020] Preferably, after adding the template agent, the stirring time is 0.5-6 hours; after the solution is evaporated to dryness, the sample is calcined at 700-1000℃ for 2-12 hours.

[0021] Preferably, the etching solution is one of sodium hydroxide solution, potassium hydroxide solution or hydrofluoric acid, with a solute molar fraction of 0.01-0.5 mol / L. The amount of etching solution added should be excessive, and the mass ratio of the etching solution to the carrier is 2:1 to 5:1. The carrier is etched three times, with each etching lasting 2 hours.

[0022] The obtained high thermally stable methanation catalyst has an active component NiO mass fraction of 5-30%, a total auxiliary oxide mass fraction of 1-5%, and the remainder is a mesoporous magnesium aluminum spinel support.

[0023] Beneficial effects:

[0024] (1) In this invention, ordered mesoporous materials (KIT-6 and / or MCM-41) with specific pore sizes (3-5 nm) are selected as template agents. The mesoporous magnesium aluminum spinel support prepared has high thermal stability and mesoporous structure compared with traditional support. The pores are arranged in an orderly and uniform manner, providing a more favorable environment for the loading of subsequent active components and additives and the occurrence of high-concentration methanation reaction. The ordered mesoporous template agent with specific pore sizes can ensure that the magnesium aluminum spinel support prepared subsequently has a highly thermally stable skeleton. If the pore size of the mesoporous template agent is too small, the prepared magnesium aluminum spinel skeleton will be insufficient in thickness and will easily collapse during high-temperature calcination or reaction. If the pore size of the mesoporous template agent is too large, the prepared magnesium aluminum spinel will have a low pore ratio and a low specific surface area. During the reaction, the instantaneous and massive exothermic reaction can cause the active components and additives to sinter and grow. The catalyst support prepared by this invention has orderly and uniform mesoporous channels with a size between 5 and 10 nm, which is a suitable size. The active components and additives can be effectively confined in the channels, maintaining the particle size. At the same time, the 5-10 nm channels facilitate the entry and exit of reaction gases and products. For high-concentration methanation reactions, it can effectively avoid the formation of carbon deposits. When the channel size is too large, the active components and additives will migrate and aggregate during high-temperature calcination or reaction, leading to catalyst deactivation. When the channel size is too small, it is difficult for reaction gases and products to enter and exit the channels, and carbon deposits are aggravated, affecting the reaction activity.

[0025] (2) The present invention uses a vacuum impregnation method to impregnate the active components and additives. This impregnation method is simple and efficient, and can ensure that the active components and additives are loaded in the pores, effectively control the particle size and uniformity, and avoid the generation of large-sized particles.

[0026] (3) The prepared catalyst has the characteristics of high thermal stability. During the long-term high-temperature reaction process, the support can ensure that the ordered channels do not collapse, and the catalyst can effectively ensure a high specific surface area. The specific surface area decreases by less than 5%. It has a low activation temperature, can withstand high-temperature reactions, has a wide applicable temperature range, and has long-term stability. After a 500-hour high-temperature life test, the CO conversion rate can be maintained above 46%, and the CH4 selectivity can be maintained above 70%. Attached Figure Description

[0027] Figure 1 This is a high-resolution electron microscope image of the mesoporous magnesium aluminum spinel prepared in Example 2. As can be seen from the image, the pores of the support are arranged in an orderly and uniform manner. Measurements show that the pore size of the support is between 5 and 8 nm, which is beneficial for the loading of the active component and the occurrence of the methanation reaction. Detailed Implementation

[0028] The present invention will now be described in more detail with reference to the following specific embodiments. This is for illustrative purposes only and should not be construed as limiting the scope of the present invention.

[0029] Example 1

[0030] Preparation of mesoporous magnesium aluminum spinel (KIT-6 template). 25.64 g of magnesium nitrate hexahydrate and 75.03 g of aluminum nitrate nonahydrate were weighed into a beaker, and 200 mL of deionized water was added. The mixture was stirred and dissolved to obtain solution A. Solution A was heated in a water bath at 50 °C, and 20 g of template agent KIT-6 (pore size 3–5 nm) was added. The mixture was stirred for 3 hours to ensure complete and homogeneous mixing, resulting in a suspension-like mixture B. A 5% (w / w) weakly alkaline sodium carbonate solution was added dropwise to mixture B until the pH reached approximately 9. The mixture was then heated in a water bath at 50 °C and stirred until completely evaporated. The resulting solid was calcined in a muffle furnace at 900 °C for 3 hours to obtain a magnesium aluminum spinel support with the template agent. The above-mentioned support was added to a beaker, and twice the amount of 0.1 mol / L sodium hydroxide solution was added. Etching was carried out for 2 hours, followed by filtration and etching again. This etching process was repeated 3 times. The etched sample was washed with deionized water and then calcined in a muffle furnace at 300°C for 5 hours to obtain a mesoporous magnesium aluminum spinel (KIT-6 template) support.

[0031] Preparation of 10Ni-2La-1Ce / MgAl2O4 catalyst. 10 g of the mesoporous magnesium aluminum spinel support prepared above was poured into a three-necked flask, and the flask was evacuated using a vacuum pump. 3.953 g of nickel acetylacetonate, 0.616 g of lanthanum acetylacetonate, and 0.212 g of cerium acetate were weighed into a beaker, and 15 mL of anhydrous ethanol was added. The mixture was stirred thoroughly until completely dissolved, and then added to the vacuum flask through a constant-pressure dropping funnel, mixing thoroughly with the support in the flask. The sample was transferred to an oven and dried at 80 °C for 10 hours. Finally, it was placed in a muffle furnace and calcined at 800 °C for 3 hours to obtain the 10Ni-2La-1Ce / MgAl2O4 catalyst.

[0032] Example 2

[0033] Preparation of mesoporous magnesium aluminum spinel (KIT-6 template). 51.71 g of magnesium acetylacetonate dihydrate and 81.70 g of aluminum isopropoxide were weighed into a beaker, and 500 mL of ethanol was added. The mixture was stirred and dissolved to obtain solution A. Solution A was heated in a water bath at 60 °C, and 35 g of template agent KIT-6 (pore size 3–5 nm) was added. The mixture was stirred for 6 hours to ensure complete and homogeneous mixing, resulting in a suspension-like mixture B. A 15% (w / w) ammonia solution was added dropwise to mixture B until the pH reached approximately 9.5. The mixture was then heated in a water bath at 60 °C and stirred until completely evaporated. The resulting solid was calcined in a muffle furnace at 800 °C for 2 hours to obtain a magnesium aluminum spinel support with the template agent. The above-mentioned support was added to a beaker, and three times its mass of 0.1 mol / L potassium hydroxide solution was added. Etching was performed for 2 hours, followed by filtration, and then etching was repeated three times. The etched sample was washed with deionized water and calcined in a muffle furnace at 400°C for 6 hours to obtain a mesoporous magnesium aluminum spinel (KIT-6 template) support. Figure 1 As shown, the high-resolution electron microscopy image of the mesoporous magnesium aluminum spinel prepared using KIT-6 as a template shows that the support has a good pore structure, which is beneficial for loading active components.

[0034] Preparation of 15Ni-1Mo-1Y / MgAl2O4 catalyst. 20g of the mesoporous magnesium aluminum spinel support prepared above was poured into a three-necked flask, and the flask was evacuated using a vacuum pump. 14.072g of nickel nitrate hexahydrate, 0.457g of molybdenum pentachloride, and 0.818g of yttrium nitrate hexahydrate were weighed into a beaker, and 30mL of deionized water was added. The mixture was stirred thoroughly until completely dissolved, and then added to the vacuum flask through a constant-pressure dropping funnel, mixing thoroughly with the support in the flask. The sample was transferred to an oven and dried at 100℃ for 6 hours. Finally, it was placed in a muffle furnace and calcined at 700℃ for 5 hours to obtain the 15Ni-1Mo-1Y / MgAl2O4 catalyst.

[0035] Example 3

[0036] Preparation of mesoporous magnesium aluminum spinel (MCM-41 template). 25.86 g of magnesium acetylacetonate dihydrate and 40.85 g of aluminum isopropoxide were weighed into a beaker, and 300 mL of acetonitrile was added. The mixture was stirred and dissolved to obtain solution A. Solution A was heated in a water bath at 50 °C, and 25 g of template agent MCM-41 (pore size 3–4.5 nm) was added. The mixture was stirred for 5 hours to ensure complete and homogeneous mixing, resulting in a suspension-like mixture B. A 5% sodium bicarbonate solution was added dropwise to mixture B until the pH reached approximately 9. The mixture was then heated in a water bath at 50 °C and stirred until completely evaporated. The resulting solid was calcined in a muffle furnace at 850 °C for 4 hours to obtain a magnesium aluminum spinel support with the template agent. The above-mentioned support was added to a beaker, and 2.5 times its mass of 0.1 mol / L potassium hydroxide solution was added. Etching was carried out for 2 hours, followed by filtration and etching again. This etching process was repeated 3 times. The etched sample was washed with deionized water and then calcined in a muffle furnace at 400°C for 8 hours to obtain a mesoporous magnesium aluminum spinel (MCM-41 template) support.

[0037] Preparation of 20Ni-1.5Mo-1Zr-1Y / MgAl2O4 catalyst. 15g of the mesoporous magnesium aluminum spinel support prepared above was poured into a three-necked flask, and the flask was evacuated using a vacuum pump. 9.594g of nickel oxalate dihydrate, 0.666g of molybdenum acetylacetonate, 0.776g of zirconium acetylacetonate, and 0.231g of yttrium isopropoxide were weighed into a beaker, and 22mL of ethyl acetate was added. The mixture was stirred thoroughly until completely dissolved, and the solution was added to the vacuum flask through a constant-pressure dropping funnel, mixing thoroughly with the support in the flask. The sample was transferred to an oven and dried at 60℃ for 10 hours. Finally, it was placed in a muffle furnace and calcined at 800℃ for 2 hours to obtain the 20Ni-1.5Mo-1Zr-1Y / MgAl2O4 catalyst.

[0038] Comparative Example 1

[0039] Compared to Example 2, no template agent was added in the carrier preparation, and equal-volume impregnation was used instead of vacuum impregnation.

[0040] Preparation of magnesium aluminum spinel. 51.71 g of magnesium acetylacetonate dihydrate and 81.70 g of aluminum isopropoxide were weighed into a beaker, and 500 mL of ethanol was added. The mixture was stirred and dissolved to obtain solution A. Solution A was heated in a water bath at 60 °C. A 15% (w / w) ammonia solution was added dropwise to solution A until the pH reached approximately 9.5. The solution was then heated in a water bath at 60 °C and stirred until completely evaporated. The resulting solid was calcined in a muffle furnace at 800 °C for 2 hours to obtain a magnesium aluminum spinel support.

[0041] Preparation of 15Ni-1Mo-1Y / MgAl2O4 (without template) catalyst. The catalyst was prepared using a common equal-volume impregnation method. 14.072 g of nickel nitrate hexahydrate, 0.457 g of molybdenum pentachloride, and 0.818 g of yttrium nitrate hexahydrate were weighed into a beaker, and 30 mL of deionized water was added. The mixture was stirred thoroughly until completely dissolved. 20 g of the magnesium aluminum spinel support prepared above was added to the solution, and the mixture was stirred thoroughly. The sample was transferred to an oven and dried at 100 °C for 6 hours. Finally, it was placed in a muffle furnace and calcined at 700 °C for 5 hours to obtain the 15Ni-1Mo-1Y / MgAl2O4 (without template) catalyst.

[0042] Comparative Example 2

[0043] Using KIT-6 (pore size 7-8 nm) as a template agent, the remaining preparation steps were consistent with those in Example 2, and a 15Ni-1Mo-1Y / MgAl2O4(KIT-6)-7-8 nm catalyst was prepared.

[0044] Comparative Example 3

[0045] Using SBA-15 (pore size 7-12 nm) as a template agent, the remaining preparation steps were consistent with those in Example 2, and a 15Ni-1Mo-1Y / MgAl2O4(SBA-15)-7-12 nm catalyst was prepared.

[0046] Comparative experiment:

[0047] The catalysts prepared in the above examples and comparative examples were used to catalyze the CO2 methanation reaction. The high thermal stability methanation catalysts prepared in Examples 1-3 and the catalysts prepared in Comparative Examples 1-3 were used as catalysts to investigate their performance in catalyzing the reaction of high concentration carbon dioxide with hydrogen to produce methane.

[0048] The catalyst prepared above was pressed into tablets, crushed, and sieved to 20-40 mesh. It was then mixed with 20-40 mesh inert quartz sand at a volume ratio of 1:1, and the mixture was loaded into a reactor. The reactor was first reduced with pure hydrogen at 450°C for 5 hours, followed by a methanation test. The test settings were 600°C, 2 MPa, and a space velocity of 10000 h⁻¹. -1The feed gas composition was 20% CO2 and 80% H2. Evaluation showed that within 30 minutes of reaction, the bed temperature range for the examples was 600-616℃, and for the comparative examples, it was 600-639℃. Sampling results after 30 minutes are shown in Table 1. All catalysts prepared in the examples exhibited good CO2 methanation catalytic activity, with CO2 conversion greater than 60% and CH4 selectivity greater than 50%. In contrast, the catalysts prepared in the comparative examples showed lower activity, especially the 15Ni-1Mo-1Y / MgAl2O4 catalyst (without a template) prepared in Comparative Example 1, which had a CO2 conversion lower than 20% and a CH4 selectivity lower than 25%.

[0049] Table 1

[0050] catalyst <![CDATA[CO2 conversion rate]]> <![CDATA[CH4 selectivity]]> <![CDATA[10Ni-2La-1Ce / MgAl2O4]]> 62.8 50.6 <![CDATA[15Ni-1Mo-1Y / MgAl2O4]]> 63.9 51.3 <![CDATA[20Ni-1.5Mo-1Zr-1Y / MgAl2O4]]> 61.8 50.9 <![CDATA[15Ni-1Mo-1Y / MgAl2O4 (without using template)]]> 19.3 23.5 <![CDATA[15Ni-1Mo-1Y / MgAl2O4(KIT-6)-7~8nm]]> 50.3 45.3 <![CDATA[15Ni-1Mo-1Y / MgAl2O4(SBA-15)-7~12nm]]> 30.7 43.8

[0051] The catalysts prepared in the above examples and comparative examples were used to catalyze the CO methanation reaction. The high thermal stability methanation catalyst of 15Ni-1Mo-1Y / MgAl2O4 prepared in Example 2 and the 15Ni-1Mo-1Y / MgAl2O4(KIT-6)-7~8nm catalyst prepared in Comparative Example 2 were used as catalysts to investigate their performance in long-term high-temperature catalysis of the reaction of high concentration of carbon monoxide with hydrogen to produce methane.

[0052] The catalyst prepared above was pressed into tablets, crushed, and sieved to 20-40 mesh. It was then mixed with 20-40 mesh inert quartz sand at a volume ratio of 1:1, and the mixture was loaded into a reactor. The reactor was first reduced with pure hydrogen at 470℃ for 8 hours, followed by a methanation test. The test settings were 660℃, 2.5 MPa, and a space velocity of 20000 h⁻¹. -1 The feed gas composition was 25% CO and 75% H2. During a 500-hour long-term test, the bed temperature of the 15Ni-1Mo-1Y / MgAl2O4 high-thermal-stability methanation catalyst ranged from 660 to 681℃, and the catalyst activity did not show significant decline. The CO conversion rate remained above 46%, the CH4 selectivity was above 70%, and the bed hotspots did not shift. In contrast, the 15Ni-1Mo-1Y / MgAl2O4(KIT-6)-7~8nm catalyst prepared in Comparative Example 1 experienced a temperature runaway in the bed after the reaction started, exceeding 700℃ at its peak. Subsequently, the activity decreased significantly. After 10 hours of reaction, the CO conversion rate dropped below 5%, indicating that the active components of the catalyst underwent sintering and deactivation.

[0053] Physical adsorption tests were performed on samples of the 15Ni-1Mo-1Y / MgAl2O4 methanation catalyst before and after the reaction, which underwent a long-term test of 500 hours. The specific surface area of ​​the samples was obtained, as shown in Table 1. The catalyst had a large specific surface area before the reaction. After the long-term reaction at high temperature, the specific surface area of ​​the catalyst decreased only slightly, with a decrease rate of 2.9%.

[0054] Table 1. Specific surface area of ​​catalyst before and after reaction.

[0055] catalyst <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Before reaction of 15Ni-1Mo-1Y / MgAl2O4]]> 172 <![CDATA[After 500 hours of reaction of 15Ni-1Mo-1Y / MgAl2O4]]> 167

Claims

1. The application of a highly thermally stable methanation catalyst in the CO / CO2 methanation reaction, characterized in that, Magnesium and aluminum precursors were dissolved in a solvent by stirring to obtain solution A, which was then heated in a water bath. A template agent was added to solution A and stirred to obtain mixture B. A weak alkaline solution was added dropwise to mixture B until the pH reached 9-10, and the solution was stirred at this temperature until it was completely evaporated. The mixture was then calcined to obtain a support containing the template agent. The template was then etched using an etching solution, filtered, washed, and calcined to obtain a mesoporous magnesium-aluminum spinel support. The mesoporous magnesium-aluminum spinel was placed in a flask, evacuated, and a solution containing nickel and auxiliary precursors was added. The mixture was then dried and calcined to obtain a highly thermally stable methanation catalyst. The molar ratio of magnesium to aluminum in solution A was 1:

2. The template agent is an ordered mesoporous material with a pore size of 3~5 nm, specifically KIT-6 and / or MCM-41; the mass ratio of the amount of template agent added to the theoretically generated magnesium aluminum spinel is 1:2~2:

1.

2. The application as described in claim 1, characterized in that, The molar concentration of magnesium in solution A is 0.01-1 mol / L.

3. The application as described in claim 1, characterized in that, The water bath heating temperature is 40-90℃.

4. The application as described in claim 1, characterized in that, The magnesium precursor is at least one of magnesium nitrate, magnesium oxalate, magnesium sulfate, magnesium chloride, magnesium perchlorate, magnesium ethanol, magnesium acetate, magnesium citrate, and magnesium acetylacetonate; the aluminum precursor is at least one of aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum isopropoxide, aluminum sec-butoxide, aluminum lactate, aluminum oxalate, and aluminum acetylacetonate.

5. The application as described in claim 1, characterized in that, The nickel-containing precursor is at least one of nickel nitrate, nickel chloride, nickel sulfate, nickel perchlorate, basic nickel carbonate, nickel acetylacetone, nickel acetate, nickel oxalate, and nickel lactate.

6. The application as described in claim 1, characterized in that, The auxiliary precursor is at least one of lanthanum precursor, cerium precursor, zirconium precursor, molybdenum precursor, and yttrium precursor.

7. The application according to any one of claims 1-6, characterized in that, The obtained high thermally stable methanation catalyst has an active component NiO mass fraction of 5-30%, a total mass fraction of auxiliary oxides of 1-5%, and the remainder is a mesoporous magnesium aluminum spinel support.

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