A two-step catalytic method for methanol production using non-equilibrium plasma synergistic process

Abstract

This invention relates to the field of CO2 catalytic hydrogenation to methanol technology, specifically to a two-step catalytic method for methanol production using non-equilibrium plasma synergy. Conventional non-equilibrium plasma catalytic hydrogenation to methanol methods suffer from low CO2 conversion and methanol space-time yield, rarely reaching 80%. To address these issues, this invention provides a two-step catalytic method for methanol production using non-equilibrium plasma synergy. By employing stepwise reactions, optimizing catalyst composition, and refining the catalyst loading sequence in a dielectric barrier discharge catalytic reactor, this method significantly improves CO2 conversion and methanol selectivity in the non-equilibrium plasma synergistic two-step catalytic methanol production reaction, achieving remarkable technical benefits.

Description

Technical Field

[0001] This invention relates to the field of CO2 catalytic hydrogenation to methanol technology, specifically to a high-temperature resistant oxidation coating used at the thermocouple measuring end and its preparation method. Background Technology

[0002] Due to the inherent stability of CO2 and the need for CO2 resource utilization, catalytic hydrogenation is one of the most commonly used methods. Depending on the reaction system, the reactant carbon dioxide and hydrogen source (such as hydrogen and water) can generate different target products (such as solid carbon, low-carbon alcohols, formic acid, dimethyl ether, and low-carbon olefins). It also has the characteristics of large reactant conversion, high conversion rate, and good product selectivity, making it the focus of CO2 resource utilization development.

[0003] Currently, catalysts for the hydrogenation of CO2 to methanol are mainly divided into noble metal catalysts and non-noble metal catalysts. Commonly used noble metal catalysts include chromium-based catalysts and indium-based catalysts. Studies have shown that adding ZrO2 to Ru / In2O3 can further improve the catalytic activity of CO2 hydrogenation to methanol. When the Ru loading is 1 wt.%, the obtained Ru / In2O3-ZrO2 catalyst exhibits higher methanol selectivity at 300℃, 5 MPa, and 21000 cm⁻¹. 3 g cat -1 h -1 Under these conditions, the methanol space-time yield (STY) reached 0.685 g. MeOH h -1 g cat –1 Further research indicates that plasma-co-catalyzed MnOx / ZrO2 reaction in CO2 hydrogenation yields a methanol space-time yield of 4.5 mg / L. MeOH gcat −1 h −1 .

[0004] Research on non-precious metal catalysts has primarily focused on Cu-based catalysts. One study prepared a CuO / TiO2 supported catalyst using an impregnation method and applied it to the CO2 hydrogenation to methanol reaction, achieving a yield of 0.47-1%. Another study prepared a Cu / ZnO / Al2O3 / SiO2 catalyst, achieving a CO2 conversion rate of 12.6%, a methanol selectivity of 85.1%, and a methanol yield of 10.7%.

[0005] Non-equilibrium plasma technology generates a large number of free radicals and quasi-molecules during discharge. These molecules are chemically highly reactive and readily react with other atoms, molecules, or other free radicals to form stable atoms or molecules. It offers advantages such as high efficiency, low consumption, high controllability, and long lifespan, demonstrating promising application potential in CO2 resource utilization. Currently, many studies have employed non-equilibrium plasma technology for catalytic hydrogenation to methanol. For example, Chinese invention patent CN 109529851 A discloses a nickel-based supported catalyst and a method for plasma-catalyzed CO2 hydrogenation to methanol. This technology supports NiOx on a TiO2 support, achieving a methanol selectivity of 1%-85%. However, its drawbacks include a relatively low CO2 conversion rate, mostly between 13%-35%, reaching a maximum of 75%, but with only 1% methanol selectivity at these levels. Under other conditions, CO selectivity far exceeds methanol selectivity. Furthermore, it lacks evaluation indicators such as yield and space-time yield, and the use of precious metals in the raw material preparation process leads to high catalyst costs and a complex preparation process. Summary of the Invention

[0006] A problem with existing technologies is that conventional non-equilibrium plasma catalytic hydrogenation to methanol methods have low CO2 conversion rates, rarely reaching 80%. To address this issue, this invention provides an electrocatalytic reactor system for methanol production, comprising a dielectric barrier discharge catalytic reactor I and a dielectric barrier discharge catalytic reactor II. A drying device is installed between the dielectric barrier discharge catalytic reactor I and the dielectric barrier discharge catalytic reactor II. The dielectric barrier discharge catalytic reactor I, the dielectric barrier discharge catalytic reactor II, and the drying device are interconnected via a connecting pipe. A hydrogen inlet branch pipe is also provided in the middle of the connecting pipe between the dielectric barrier discharge catalytic reactor II and the drying device, and this hydrogen inlet branch pipe is interconnected with the connecting pipe.

[0007] Preferably, the catalyst loading zone of the dielectric barrier discharge catalytic reactor I includes several reduction catalyst loading zones, and a metal mixed powder I loading zone is provided between adjacent reduction catalyst loading zones;

[0008] The packing density of the reduction catalyst in the reduction catalyst packing zone is 0.75-1.15 g / mL;

[0009] The packing density of the metal mixed powder I packing zone is 1.5-1.8 g / mL;

[0010] The ratio of the packing length of a single reduction catalyst packing zone to that of a single metal mixed powder I packing zone along the axial direction of the dielectric barrier discharge catalytic reactor I is 5-5.5 cm: 1-2 mm;

[0011] The metal mixed powder I is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 3:1;

[0012] The reduction catalyst is γ-Al2O3 particles loaded with Fe and Cu nanoparticles.

[0013] Preferably, the diameter of the γ-Al2O3 particles is 0.5-1.2 mm, the loading of Fe on the surface of the γ-Al2O3 particles is 3.5-4.2 wt.%, and the loading of Cu on the surface of the γ-Al2O3 particles is 5.5-6.5 wt.%.

[0014] Preferably, the number of reduction catalyst loading zones is not less than three.

[0015] Preferably, the catalyst loading zone of the dielectric barrier discharge catalytic reactor II includes several hydrogenation catalyst loading zones and several metal mixed powder II loading zones, wherein the catalyst loading zones and the metal mixed powder II loading zones are alternately distributed;

[0016] The packing density of the hydrogenation catalyst in the hydrogenation catalyst packing zone is 0.75-1.15 g / mL;

[0017] The packing density of the metal mixed powder II in the metal mixed powder II packing zone is 1.5-1.8 g / mL;

[0018] The ratio of the filling length of the single hydrogenation catalyst filling zone to the single metal mixed powder II filling zone along the axial direction of the dielectric barrier discharge catalytic reactor II is 6-8 cm: 1-2 mm.

[0019] The hydrogenation catalyst is γ-Al2O3 particles supported on Fe and Ce nanoparticles.

[0020] The metal mixed powder II is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 3:1.

[0021] Preferably, the diameter of the γ-Al2O3 particles is 0.5-1.2 mm, the loading of Fe on the surface of the γ-Al2O3 particles is 3.5-4.2 wt.%, and the loading of Ce on the surface of the γ-Al2O3 particles is 7.5-8.5 wt.%.

[0022] Preferably, the number of hydrogenation catalyst loading zones is not less than four.

[0023] Preferably, the average particle size of Fe elemental powder in metal mixed powder I is 200-400 mesh, and the average particle size of Al elemental powder is 200-400 mesh.

[0024] Preferably, the average particle size of Fe elemental powder in metal mixed powder II is 200-400 mesh, and the average particle size of Al elemental powder is 200-400 mesh.

[0025] A two-step catalytic method for the production of methanol using non-equilibrium plasma synergistic catalysis includes the following steps:

[0026] (1) CO2 reduction: The mixture I formed by CO2 and H2 is reduced to CO in the dielectric barrier discharge catalytic reactor I. The generated CO enters the drying device through the connecting pipe for thorough drying.

[0027] (2) CO catalytic hydrogenation to methanol

[0028] After the mixed gas I obtained in step (1) is fully dried by the condenser, it is mixed with H2 supplemented by the hydrogen inlet branch to form mixed gas II, and together they enter the dielectric barrier discharge catalytic reactor II to carry out catalytic reaction to obtain methanol.

[0029] Preferably, the volume ratio of CO2 to H2 in the mixed gas I is 1:3-3.5, the total flow rate of the reaction gas is 10-15 SCCM, the gas pressure of the mixed gas I in the dielectric barrier discharge catalytic reactor I is not greater than 1.4 bar, the reaction temperature is 60-90℃, and the residence time of the mixed gas I in the discharge region should be 7-14 s.

[0030] Preferably, the volume ratio of CO to H2 in the mixed gas II is 1:5-6, the total flow rate of the reaction gas is 10-15 SCCM, the gas pressure of the mixed gas II in the dielectric barrier discharge catalytic reactor II is not greater than 1.2 bar, the reaction temperature is 75-100℃, and the residence time of the mixed gas II in the discharge region should be 40-50 s.

[0031] The present invention has the following beneficial effects:

[0032] (1) By optimizing the composition of the catalyst and the loading order of the catalyst in the dielectric barrier discharge catalytic reactor, the present invention significantly improves the CO2 conversion rate and methanol selectivity in the non-equilibrium plasma synergistic two-step catalytic methanol production reaction, and achieves significant technical effects.

[0033] (2) In this invention, metal mixed powder is filled in the catalyst filling zone of the dielectric barrier discharge catalytic reactor. In the plasma discharge reaction, these metal mixed powders can react efficiently with oxygen atoms (O) in the gas and realize the reduction process in the environment containing hydrogen atoms (H). This mechanism significantly increases the reaction path of oxygen atoms in the reactants, thereby effectively guiding the reaction towards the target product and playing a protective role for the catalyst in the process. Attached Figure Description

[0034] Figure 1 : Schematic diagram of the structure of dielectric barrier discharge catalytic reactor I in Example 1.

[0035] Figure 2 : Schematic diagram of the dielectric barrier discharge catalytic reactor II in Example 1.

[0036] Figure 3 Example 1: Process flow diagram of the non-equilibrium plasma-assisted two-step catalytic methanol production.

[0037] Figure 4 : Schematic diagram of the drying device in Example 1. Detailed Implementation

[0038] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are merely illustrative examples of implementation of the present invention and are not intended to limit the scope of the present invention.

[0039] The reduction catalyst used in the following embodiments of the present invention is supported by γ-Al2O3 particles (purchased from Jiezhiyuan Water Treatment Materials Factory), with an average diameter of 1 mm. The surface of the γ-Al2O3 particles is loaded with two kinds of nanoparticles, Fe and Cu. The loading amount of Fe on the surface of the γ-Al2O3 particles is 3.5 wt.%, and the loading amount of Cu on the surface of the γ-Al2O3 particles is 5.5 wt.%.

[0040] The reduction catalyst is prepared as follows:

[0041] (1) Dry the γ-Al2O3 microspheres (purchased from Jiezhiyuan Water Treatment Materials Factory, item number: 1344-28-1) under vacuum at 60℃ for 1 hour and set aside for later use;

[0042] (2) Cu(NO3)2·3H2O (purchased from Shanghai Aladdin Technology Co., Ltd., item number: C140879) and Fe(NO3)3·9H2O (purchased from Shanghai Aladdin Technology Co., Ltd., item number: F100211) precursors were dissolved in deionized water to obtain Cu ion aqueous solution with a mass concentration of 1.10 g / mL and Fe ion aqueous solution with a mass concentration of 1.31 g / mL, respectively.

[0043] (3) Take 1 mL of Cu ion aqueous solution and 1 mL of Fe ion aqueous solution and mix them evenly. Then add 5 g of γ-Al2O3 small balls, stir slightly, and let it stand at room temperature for 1 h for aging. Stir slightly again and let it stand at room temperature for 11 h for aging.

[0044] (4) The mixture after aging at room temperature for 12 hours was placed in a vacuum drying oven and dried at 60°C to remove deionized water;

[0045] (5) After cooling to room temperature, remove the mixture and place it in a muffle furnace for calcination at 420°C for 5 hours;

[0046] (6) After calcination, the catalyst is obtained by naturally cooling to room temperature.

[0047] The hydrogenation catalyst used in the following embodiments of the present invention is γ-Al2O3 particles with Fe and Ce nanoparticles loaded on their surface. The diameter of the γ-Al2O3 particles is 1.2 mm, the loading amount of Fe on the surface of the γ-Al2O3 particles is 4.2 wt.%, and the loading amount of Ce on the surface of the γ-Al2O3 particles is 7.5 wt.%.

[0048] The preparation method of the hydrogenation catalyst is as follows:

[0049] (1) Dry the γ-Al2O3 microspheres (purchased from Jiezhiyuan Water Treatment Materials Factory, item number: 1344-28-1) under vacuum at 60℃ for 1 hour and set aside for later use;

[0050] (2) Ce(NO3)3·6H2O (purchased from Shanghai Aladdin Technology Co., Ltd., item number: C105378) and Fe(NO3)3·9H2O (purchased from Shanghai Aladdin Technology Co., Ltd., item number: F100211) precursors were dissolved in deionized water to obtain Ce ion aqueous solution with a mass concentration of 1.26 g / mL and Fe ion aqueous solution with a mass concentration of 1.58 g / mL, respectively.

[0051] (3) Take 1 mL of Ce ion aqueous solution and 1 mL of Fe ion aqueous solution and mix them evenly. Then add 5 g of γ-Al2O3 small balls, stir slightly, and let it stand at room temperature for 1 h for aging. Stir slightly again and let it stand at room temperature for 11 h for aging.

[0052] (4) The mixture after aging at room temperature for 12 hours was placed in a vacuum drying oven and dried at 60°C to remove deionized water;

[0053] (5) After cooling to room temperature, remove the mixture and place it in a muffle furnace for calcination at 540°C for 5 hours;

[0054] (6) After calcination, the hydrogenation catalyst is obtained by naturally cooling to room temperature.

[0055] The dielectric barrier discharge catalytic reactor I used in this embodiment of the invention is a conventional dielectric barrier discharge (DBD) reactor, consisting of a needle electrode, an insulating tube (made of Al2O3, corundum tube purchased from Huadong Electric Heating, model: 95G-12-8-320), an outer electrode, a heat preservation system, and a catalyst filling area. The needle electrode is positioned at the centerline of the insulating tube, with an outer diameter of 1 mm, a dielectric constant of 4.7, a wall thickness of 2 mm, an outer diameter of 12 mm, an inner diameter of 8 mm, and a distance of 4 mm between the needle electrode (tungsten alloy) and the inner wall of the insulating tube. The outer electrode covers the outer wall of the insulating tube and is grounded. The outer electrode and the needle electrode form a discharge area with a length of 250 mm. The catalyst filling area includes a reduction catalyst filling area and a metal mixed powder I filling area.

[0056] A metal mixed powder I loading zone is provided between each adjacent reduction catalyst loading zone;

[0057] The packing density of the reduction catalyst in the reduction catalyst packing zone is 1 g / mL;

[0058] The packing density of the metal mixed powder I packing zone is 1.6 g / mL;

[0059] The filling length of a single reduction catalyst filling zone is 5 cm, and the filling length of a single metal mixed powder I filling zone is 1 mm;

[0060] There are 3 reduction catalyst loading zones.

[0061] The insulation system is located on the outside of the outer electrode.

[0062] Along the gas flow direction, the dielectric barrier discharge catalytic reactor I is first filled with reduction catalyst particles, then with metal mixed powder I, and then alternately filled, for a total of three sections of reduction catalyst particles and two sections of metal mixed powder I. The entire catalyst filling zone is sealed at both ends with quartz glass wool, and a polytetrafluoroethylene (PTFE) filter membrane separates the reduction catalyst particles and metal mixed powder I. During the reduction process, the applied voltage amplitude is 8 kV, and the discharge frequency is 10 kHz.

[0063] The structure of the dielectric barrier discharge catalytic reactor II is the same as that of the dielectric barrier discharge catalytic reactor I, except that the catalyst filling zone of the dielectric barrier discharge catalytic reactor II is provided with a hydrogenation catalyst filling zone and a metal mixed powder II filling zone. There are 4 hydrogenation catalyst filling zones, and a metal mixed powder II filling zone is provided between each adjacent hydrogenation catalyst filling zone. The packing density of the hydrogenation catalyst in the hydrogenation catalyst filling zone is 0.75 g / mL.

[0064] The packing density of metal mixed particles II in the metal mixed powder II packing zone is 1.6 g / mL;

[0065] The packing length of a single hydrogenation catalyst packing zone is 6 cm;

[0066] The filling length of the single metal mixed particle II filling zone is 2 mm;

[0067] During hydrogenation, the applied voltage amplitude is 30kV and the discharge frequency is 20 kHz.

[0068] Along the gas flow direction, the hydrogenation catalyst is filled first, followed by metal mixed powder II, and then the filling is repeated alternately, for a total of four sections of hydrogenation catalyst and three sections of metal mixed powder II. The two ends of the entire catalyst filling zone are sealed with quartz glass wool, and a polytetrafluoroethylene filter membrane is used to separate the hydrogenation catalyst and metal mixed powder II.

[0069] In this embodiment of the invention, the metal mixed powder I is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 3:1, with the Fe elemental powder having a particle size of 200 mesh and the Al elemental powder having a particle size of 200 mesh.

[0070] In this embodiment of the invention, the metal mixed powder II is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 3:1, with the Fe elemental powder having a particle size of 200 mesh and the Al elemental powder having a particle size of 200 mesh. Example 1

[0071] A two-step catalytic method for methanol production using non-equilibrium plasma synergistic catalysis, comprising the following steps:

[0072] (1) CO2 reduction: The mixture I formed by CO2 and H2 is reduced to CO in the dielectric barrier discharge catalytic reactor I. The generated CO enters the drying device through the connecting pipe for thorough drying.

[0073] (2) CO catalytic hydrogenation to methanol

[0074] After the mixed gas I obtained in step (1) is fully dried by the condenser, it is mixed with H2 supplemented by the hydrogen inlet branch to form mixed gas II, and together they enter the dielectric barrier discharge catalytic reactor II to carry out catalytic reaction to obtain methanol.

[0075] The volume ratio of CO2 to H2 in mixed gas I is 1:3. The total flow rate of the reactant gas in dielectric barrier discharge catalytic reactor I is 10 SCCM. The gas pressure of mixed gas I in dielectric barrier discharge catalytic reactor I is 1.3 bar. The reaction temperature is 60℃. The residence time of mixed gas I in the discharge region is 10.6 s.

[0076] The product gas exiting the dielectric barrier discharge catalytic reactor I is mainly composed of CO, but it also contains a considerable concentration of H2O. The presence of H2O reduces the activity of the catalyst in the dielectric barrier discharge catalytic reactor II and increases the difficulty of discharge; therefore, it needs to be dried using a drying device (as per the instruction manual). Figure 4 The dehydration process is carried out as shown in the figure. The dehydration principle of the drying equipment is to use condensation dehydration (using an ice-water mixture in the dryer to create a 0℃ low-temperature environment) to fully dry the gas obtained from the reaction in catalytic reactor I. The dried gas flows out of the drying equipment and is then mixed with H2 to form mixed gas II. In this example, a mass flow meter is used to control the H2 flow rate to achieve a CO to H2 volume ratio of 1:5. At this time, the total flow rate of the reaction gas is 11 SCCM. The gas pressure of mixed gas II in dielectric barrier discharge catalytic reactor II is about 1.1 bar, and the reaction temperature is controlled at 75℃. The residence time of mixed gas II in the discharge region should be 49 s. The volume fraction of CO2, methanol, and other gases in the final gas produced by the reaction is measured using a gas chromatograph. The volume of the final gas produced is calculated using a soap film flow meter, and the volume of condensate obtained in the condenser is measured. The CO2 conversion rate and methanol selectivity are calculated using the following formulas:

[0077] ,

[0078] Where and represent the number of moles of CO2 initially introduced into the reaction and the number of moles of CO2 remaining after the reaction, respectively.

[0079] The selectivity of the product CH3OH is defined as follows:

[0080] ,

[0081] in, These figures represent the number of moles of CO generated during the reaction. After the reaction, the CO2 conversion rate reached 80.15%, and the methanol selectivity reached 50.83%.

[0082] To compare the experimental results of Example 1, the following 15 experiments were also conducted based on the basic content of Example 1 of the present invention.

[0083] Comparative Example 1 is the same as Example 1, except that in Comparative Example 1, the dielectric barrier discharge catalytic reactor I is filled with a reduction catalyst first, and then with metal mixed powder I along the gas flow direction. The reduction catalyst filling area and the metal mixed powder I filling area are filled alternately, and the number of reduction catalyst filling areas is 2.

[0084] Comparative Example 2 is the same as Example 1, except that in Comparative Example 2, hydrogenation catalyst is first filled into the dielectric barrier discharge catalytic reactor II along the gas flow direction, followed by metal mixed powder II. The hydrogenation catalyst filling zone and the metal mixed powder II filling zone are filled alternately, and the number of hydrogenation catalyst filling zones is 3.

[0085] Comparative Example 3 is the same as Example 1, except that the dielectric barrier discharge catalytic reactor I of Comparative Example 3 is not filled with metal mixed powder I, and the filling length of the reduction catalyst filling zone is 15 cm.

[0086] Comparative Example 4 is the same as Example 1, except that the dielectric barrier discharge catalytic reactor II of Comparative Example 4 is not filled with metal mixed powder, and the filling length of the hydrogenation catalyst filling zone is 24 cm.

[0087] Comparative Example 5 is the same as Example 1, except that the dielectric barrier discharge catalytic reactor I of Comparative Example 5 is not filled with metal mixed powder I, and the dielectric barrier discharge catalytic reactor II is not filled with metal mixed powder II. The filling length of the reduction catalyst filling zone is 15 cm, and the filling length of the hydrogenation catalyst filling zone is 24 cm.

[0088] Comparative Example 6 is the same as Example 1, except that in Comparative Example 6, the filling length of each section of the reduction catalyst filling zone in the dielectric barrier discharge catalytic reactor I is 2 cm.

[0089] Comparative Example 7 is the same as Example 1, except that in Comparative Example 7, the filling length of each section of the reduction catalyst filling zone in the dielectric barrier discharge catalytic reactor I is 4 cm.

[0090] Comparative Example 8 is the same as Example 1, except that in Comparative Example 8, the filling length of each section of the reduction catalyst filling zone in the dielectric barrier discharge catalytic reactor I is 6 cm.

[0091] Comparative Example 9 is the same as Example 1, except that in Comparative Example 9, the filling length of each hydrogenation catalyst filling zone in the dielectric barrier discharge catalytic reactor II is 2 cm.

[0092] Comparative Example 10 is the same as Example 1, except that in Comparative Example 10, the filling length of each hydrogenation catalyst filling zone in the dielectric barrier discharge catalytic reactor II is 4 cm.

[0093] Comparative Example 11 is the same as Example 1, except that in Comparative Example 11, the filling length of each hydrogenation catalyst filling zone in the dielectric barrier discharge catalytic reactor II is 10 cm.

[0094] Comparative Example 12 is the same as Example 1, except that in Comparative Example 12, the Fe elemental powder and Al elemental powder in the metal mixed powder I of the dielectric barrier discharge catalytic reactor I are mixed in a mass ratio of 1:3.

[0095] Comparative Example 13 is the same as Example 1, except that in Comparative Example 13, the Fe elemental powder and Al elemental powder in the metal mixed powder I of the dielectric barrier discharge catalytic reactor I are mixed in a mass ratio of 1:1.

[0096] Comparative Example 14 is the same as Example 1, except that in Comparative Example 14, the Fe elemental powder and Al elemental powder in the metal mixed powder II of the dielectric barrier discharge catalytic reactor II are mixed in a mass ratio of 1:3.

[0097] Comparative Example 15 is the same as Example 1, except that the metal mixed powder II in the dielectric barrier discharge catalytic reactor II in Comparative Example 15 is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 1:1.

[0098] The test data of CO2 conversion rate, methanol selectivity, and methanol space-time yield obtained in Example 1 and Comparative Examples 1-15 of this invention are shown in Table 1.

[0099] Table 1

[0100] ,

[0101] Continued from Table 1

[0102] ,

[0103] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An electrocatalytic reactor system for catalytic methanol production, characterized in that, The reactor includes a dielectric barrier discharge catalytic reactor I and a dielectric barrier discharge catalytic reactor II. A drying device is provided between the dielectric barrier discharge catalytic reactor I and the dielectric barrier discharge catalytic reactor II. The dielectric barrier discharge catalytic reactor I, the dielectric barrier discharge catalytic reactor II, and the drying device are interconnected through a connecting pipe. A hydrogen inlet branch pipe is also provided in the middle of the connecting pipe between the dielectric barrier discharge catalytic reactor II and the drying device. The hydrogen inlet branch pipe is interconnected with the connecting pipe. The catalyst loading zone of the dielectric barrier discharge catalytic reactor I includes several reduction catalyst loading zones, with a metal mixed powder I loading zone located between adjacent reduction catalyst loading zones; the metal mixed powder I is a mixture of Fe elemental powder and Al elemental powder; the reduction catalyst is γ-Al₂O₃ particles loaded with both Fe and Cu nanoparticles, with Fe loading on the surface of the γ-Al₂O₃ particles at 3.5-4.2 wt.% and Cu loading on the surface of the γ-Al₂O₃ particles at 5.5-6.5 wt.%; the dielectric barrier... The catalyst loading zone of the discharge catalytic reactor II includes several hydrogenation catalyst loading zones and several metal mixed powder II loading zones, which are alternately distributed. The metal mixed powder II is a mixture of Fe elemental powder and Al elemental powder. The hydrogenation catalyst is γ-Al2O3 particles loaded with Fe and Ce nanoparticles, with Fe loading on the surface of the γ-Al2O3 particles at 3.5-4.2 wt.% and Ce loading on the surface of the γ-Al2O3 particles at 7.5-8.5 wt.%.

2. The electrocatalytic reactor system for methanol production according to claim 1, characterized in that, The packing density of the reduction catalyst in the reduction catalyst packing zone is 0.75-1.15 g / mL; The packing density of the metal mixed powder I packing zone is 1.5-1.8 g / mL; The ratio of the packing length of a single reduction catalyst packing zone to that of a single metal mixed powder I packing zone along the axial direction of the dielectric barrier discharge catalytic reactor I is 5-5.5 cm: 1-2 mm; The metal mixed powder I is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 3:

1.

3. The electrocatalytic reactor system for methanol production according to claim 2, characterized in that, In the reduction catalyst, the diameter of the γ-Al2O3 particles is 0.5-1.2 mm.

4. The electrocatalytic reactor system for methanol production according to claim 2, characterized in that, The number of reduction catalyst loading zones shall not be less than three.

5. The electrocatalytic reactor system for methanol production according to claim 1, characterized in that, The packing density of the hydrogenation catalyst in the hydrogenation catalyst packing zone is 0.75-1.15 g / mL; The packing density of the metal mixed powder II in the metal mixed powder II packing zone is 1.5-1.8 g / mL; The ratio of the packing length of a single hydrogenation catalyst packing zone to that of a single metal mixed powder II packing zone along the axial direction of the dielectric barrier discharge catalytic reactor II is 6-8 cm: 1-2 mm; The metal mixed powder II is a mixture of Fe elemental powder and Al elemental powder in a mass ratio of 3:

1.

6. The electrocatalytic reactor system for methanol production according to claim 5, characterized in that, In the hydrogenation catalyst, the diameter of the γ-Al2O3 particles is 0.5-1.2 mm.

7. The electrocatalytic reactor system for methanol production according to claim 5, characterized in that, The number of hydrogenation catalyst loading zones shall not be less than four.

8. A method for the two-step catalytic production of methanol using non-equilibrium plasma synergistic catalysis, characterized in that, The preparation of methanol using the electrocatalytic reactor system for catalytic methanol production as described in claim 1 includes the following steps: (1) CO2 reduction: The mixture I formed by CO2 and H2 is reduced to CO in the dielectric barrier discharge catalytic reactor I. The generated CO enters the drying device through the connecting pipe for thorough drying. (2) CO catalytic hydrogenation to methanol After the mixed gas I obtained in step (1) is fully dried by the condenser, it is mixed with H2 supplemented by the hydrogen inlet branch to form mixed gas II, and together they enter the dielectric barrier discharge catalytic reactor II to carry out catalytic reaction to obtain methanol.

9. The method for methanol production via a non-equilibrium plasma-assisted two-step catalytic process according to claim 8, characterized in that, The volume ratio of CO2 to H2 in mixed gas I is 1:3-3.5, the total flow rate of the reaction gas is 10-15 SCCM, the gas pressure of mixed gas I in dielectric barrier discharge catalytic reactor I is not greater than 1.4 bar, the reaction temperature is 60-90℃, and the residence time of mixed gas I in the discharge region should be 7-14 s.

10. The method for non-equilibrium plasma-assisted two-step catalytic production of methanol according to claim 8, characterized in that, The volume ratio of CO to H2 in mixed gas II is 1:5-6, the total flow rate of the reaction gas is 10-15 SCCM, the gas pressure of mixed gas II in dielectric barrier discharge catalytic reactor II is not greater than 1.2 bar, the reaction temperature is 75-100℃, and the residence time of mixed gas II in the discharge region should be 40-50 s.

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