Method for preparing methanol through catalysis of non-equilibrium state plasma and two-step method

Abstract

The invention relates to the technical field of methanol preparation through CO2 catalytic hydrogenation, in particular to a method for preparing methanol through catalysis of a non-equilibrium state plasma synergistic two-step method. According to a conventional method for preparing methanol through catalytic hydrogenation of a non-equilibrium plasma technology, the CO2 conversion rate and the space-time yield of methanol are relatively low and are difficult to reach 80%. In order to solve the problems, the invention provides the method for preparing methanol through catalysis by using the non-equilibrium state plasma and the two-step method, and through step-by-step reaction, the composition of a catalyst and the filling sequence of the catalyst in a dielectric barrier discharge catalytic reactor are optimized; and the conversion rate of CO2 and the selectivity of methanol in the reaction of preparing methanol through catalysis of a non-equilibrium state plasma synergistic two-step method are remarkably improved, and a remarkable technical effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of CO2 catalytic hydrogenation to methanol, and in particular to a high-temperature oxidation-resistant coating applied to a thermocouple measuring end and a preparation method thereof. Background Art

[0002] As the main greenhouse gas, carbon dioxide emissions will cause harm to the natural environment. In 2013-2022, the total carbon dioxide emissions increased by an average of 0.14% per year. Therefore, the importance of CO2 resource utilization has become more prominent and has become an important issue for industrial development. Due to the stability of CO2 itself and the demand for CO2 resource utilization, catalytic hydrogenation is one of the most commonly used methods. Affected by the reaction system, the reaction gas carbon dioxide and hydrogen source (such as hydrogen, water) can generate different target products (such as solid carbon, low-carbon alcohols, formic acid, dimethyl ether, and low-carbon olefins, etc.). At the same time, it has the characteristics of large reactant conversion, high conversion rate, and good product selectivity, becoming the development focus of CO2 resource utilization.

[0003] At present, the catalysts for the hydrogenation of CO2 to methanol are mainly divided into precious metal catalysts and non-precious metal catalysts. Commonly used precious metal catalysts include chromium-based catalysts, indium-based catalysts, etc. 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 1wt.%, the Ru / In2O3-ZrO2 catalyst has higher methanol selectivity at 300℃, 5MPa, 21000cm 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 Other studies have shown that plasma-assisted MnOx / ZrO2 can produce a methanol space-time yield of 4.5 mg in CO2 hydrogenation. MeOH gcat -1 h -1 .

[0004] The research on non-precious metal catalysts is mainly based on Cu-based catalysts. A study used the impregnation method to prepare a CuO / TiO2 supported catalyst, and used it for the CO2 hydrogenation to methanol reaction, obtaining a yield of 0.47-1%. A study prepared a Cu / ZnO / Al2O3 / SiO2 catalyst with 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 excimers during the discharge process. Their chemical properties are very active and they can easily react with other atoms, molecules or other free radicals to form stable atoms or molecules. They have the advantages of high efficiency, low consumption, high controllability and long service life, and show good application potential in CO2 resource utilization. At present, many studies have adopted non-equilibrium plasma technology to catalyze hydrogenation to produce methanol. For example, Chinese invention patent CN 109529851 A discloses a method named: a nickel-based supported catalyst and a method for using its plasma to catalyze CO2 hydrogenation to produce methanol. This technology loads NiOx on a TiO2 carrier, with a methanol selectivity of 1%-85%. The disadvantage is that the conversion rate of CO2 is low, mostly between 13%-35%, and the highest reaches 75%, but at this time the methanol selectivity is only 1%, and the CO selectivity under other conditions far exceeds the methanol selectivity. At the same time, there is a lack of evaluation indicators such as yield and space-time yield, and the use of precious metals in the raw material preparation process leads to a high catalyst cost and a relatively complicated preparation process. Summary of the invention

[0006] The problem in the prior art is that the CO2 conversion rate of the conventional non-equilibrium plasma technology catalytic hydrogenation method for methanol production is low and it is difficult to reach 80%. In view of the above problems, the present invention provides an electrocatalytic reactor device system for catalytic methanol production, which includes a dielectric barrier discharge catalytic reactor I and a dielectric barrier discharge catalytic reactor II, a drying device is arranged between the dielectric barrier discharge catalytic reactor I and the dielectric barrier discharge catalytic reactor II, the dielectric barrier discharge catalytic reactor I and the dielectric barrier discharge catalytic reactor II and the drying device are interconnected through a connecting pipe, and a hydrogen inlet branch pipe is also arranged in the middle of the connecting pipe between the dielectric barrier discharge catalytic reactor II and the drying device, and the hydrogen inlet branch pipe is interconnected with the connecting pipe.

[0007] Preferably, the catalyst loading area of ​​the dielectric barrier discharge catalytic reactor I includes a plurality of reduction catalyst loading areas, and a metal mixed powder I loading area is provided between adjacent reduction catalyst loading areas;

[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 area is 1.5-1.8 g / mL;

[0010] The ratio of the filling length of a single reduction catalyst filling area to that of a single metal mixed powder I filling area 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 single substance powder and Al single substance powder in a mass ratio of 3:1;

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

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

[0014] Preferably, the number of reduction catalyst loading areas is not less than 3.

[0015] Preferably, the catalyst loading area of ​​the dielectric barrier discharge catalytic reactor II includes a plurality of hydrogenation catalyst loading areas and a plurality of metal mixed powder II loading areas, and the catalyst loading areas and the metal mixed powder II loading areas are alternately distributed;

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

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

[0018] The ratio of the filling length of the single hydrogenation catalyst filling area to the single metal mixed powder II filling area 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 loaded with two kinds of nanoparticles of Fe and Ce.

[0020] The metal mixed powder II is a mixture of Fe single substance powder and Al single substance 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 amount of Fe on the surface of the γ-Al2O3 particles is 3.5-4.2 wt.%, and the loading amount of Ce on the surface of the γ-Al2O3 particles is 7.5-8.5 wt.%.

[0022] Preferably, the number of hydrogenation catalyst packing areas is not less than 4.

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

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

[0025] A method for preparing methanol by non-equilibrium plasma synergistic two-step catalysis, the preparation method comprising the following steps:

[0026] (1) CO2 reduction: the mixed gas I formed by CO2 and H2 is reduced to CO in the dielectric barrier discharge catalytic reactor I, and the generated CO enters the drying device through the connecting pipe and is fully dried;

[0027] (2) Catalytic hydrogenation of CO to methanol

[0028] The mixed gas I obtained in step (1) is fully dried by the condenser and then combined with H2 added from the hydrogen inlet branch to form a mixed gas II, which then enters the dielectric barrier discharge catalytic reactor II for 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°C, and the residence time of the mixed gas I in the discharge area should be 7-14s.

[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°C, and the residence time of the mixed gas II in the discharge area should be 40-50s.

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

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

[0033] (2) In the present invention, metal mixed powders are filled at intervals in the catalyst loading area of ​​the dielectric barrier discharge catalytic reactor. In the plasma discharge reaction, these metal mixed powders can efficiently react with oxygen atoms (O) in the gas and simultaneously realize the reduction process in an environment containing hydrogen atoms (H). This mechanism significantly increases the reaction path of oxygen atoms in the reactants, thereby effectively guiding the reaction toward the direction of the target product and protecting the catalyst in the process. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0037] Figure 4 : Schematic diagram of the structure of the drying device in Example 1. DETAILED DESCRIPTION

[0038] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments 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 Material 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 3.5wt.%, and the loading amount of Cu on the surface of the γ-Al2O3 particles is 5.5wt.%.

[0040] The preparation method of the reduction catalyst is as follows:

[0041] (1) γ-Al2O3 pellets (purchased from Jiezhiyuan Water Treatment Material Factory, product number: 1344-28-1) were vacuum dried at 60°C for 1 h and set aside;

[0042] (2) Cu(NO3)2·3H2O (purchased from Shanghai Aladdin Technology Co., Ltd., catalog number: C140879) and Fe(NO3)3·9H2O (purchased from Shanghai Aladdin Technology Co., Ltd., catalog number: F100211) precursors were dissolved in deionized water to obtain a Cu ion aqueous solution with a mass concentration of 1.10 g / mL and a 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 balls, stir lightly, and let stand at room temperature for 1 h, stir lightly again, and let stand at room temperature for 11 h;

[0044] (4) placing the mixture after aging for 12 h at room temperature in a vacuum drying oven and vacuum drying at 60° C. to remove deionized water;

[0045] (5) After cooling to room temperature, the mixture was taken out and placed in a muffle furnace and calcined at 420° C. for 5 h;

[0046] (6) After calcination, the catalyst is naturally cooled to room temperature to obtain a reduced catalyst.

[0047] The hydrogenation catalyst used in the following examples of the present invention is γ-Al2O3 particles with two kinds of nanoparticles of Fe and Ce loaded on the 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) γ-Al2O3 pellets (purchased from Jiezhiyuan Water Treatment Material Factory, product number: 1344-28-1) were vacuum dried at 60°C for 1 h and set aside;

[0050] (2) Ce(NO3)3·6H2O (purchased from Shanghai Aladdin Technology Co., Ltd., catalog number: C105378) and Fe(NO3)3·9H2O (purchased from Shanghai Aladdin Technology Co., Ltd., catalog 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 balls, stir lightly, and let stand at room temperature for 1 h, stir lightly again, and let stand at room temperature for 11 h;

[0052] (4) placing the mixture after aging for 12 h at room temperature in a vacuum drying oven and vacuum drying at 60° C. to remove deionized water;

[0053] (5) After cooling to room temperature, the mixture was taken out and placed in a muffle furnace and calcined at 540° C. for 5 h;

[0054] (6) After calcination, the mixture is naturally cooled to room temperature to obtain a hydrogenation catalyst.

[0055] The dielectric barrier discharge catalytic reactor I used in the embodiment of the present invention has a structure of a conventional dielectric barrier discharge (DBD) reactor, which is composed of a needle-shaped electrode, an insulating tube (made of Al2O3, the corundum tube is purchased from East China Electric Heating, model: 95G-12-8-320), an external electrode, a heat preservation system and a catalyst filling area. The needle-shaped electrode is arranged at the center line of the insulating tube, and the outer diameter of the needle-shaped electrode is 1mm; the dielectric constant is 4.7, the wall thickness is 2mm, the outer diameter is 12mm, the inner diameter is 8mm, and the distance between the needle-shaped electrode (tungsten alloy) and the inner wall of the insulating tube is 4mm; the external electrode is coated on the outer wall of the insulating tube and is grounded; the external electrode and the needle-shaped electrode form a discharge area, the length of which is 250mm, and the catalyst filling area is provided with a reduction catalyst filling area and a metal mixed powder I filling area;

[0056] A metal mixed powder I filling area is provided between adjacent reduction catalyst filling areas;

[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 area is 1.6 g / mL;

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

[0060] The number of reduction catalyst loading areas is 3.

[0061] The insulation system is arranged outside the outer electrode.

[0062] Along the gas flow direction, the dielectric barrier discharge catalytic reactor I is first filled with reduction catalyst particles, then filled with metal mixed powder I, and then alternately filled, with a total of three sections of reduction catalyst particles and two sections of metal mixed powder I. The two ends of the entire catalyst filling area are blocked with quartz glass wool, and a polytetrafluoroethylene filter membrane is used to separate the reduction catalyst particles and the metal mixed powder I. During the reduction process, the applied voltage amplitude is 8kV and the discharge frequency is 10kHz.

[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: a hydrogenation catalyst filling area and a metal mixed powder II filling area are arranged in the catalyst filling area of ​​the dielectric barrier discharge catalytic reactor II, the number of hydrogenation catalyst filling areas is 4, and a metal mixed powder II filling area is arranged between adjacent hydrogenation catalyst filling areas, and the packing density of the hydrogenation catalyst in the hydrogenation catalyst filling area is 0.75 g / mL;

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

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

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

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

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

[0069] In the embodiment of the present invention, the metal mixed powder I is a mixture of Fe single substance powder and Al single substance powder according to a mass ratio of 3:1, the particle size of the Fe single substance powder is 200 mesh, and the particle size of the Al single substance powder is 200 mesh.

[0070] In the embodiment of the present invention, the metal mixed powder II is a mixture of Fe single substance powder and Al single substance powder in a mass ratio of 3:1, the particle size of the Fe single substance powder is 200 mesh, and the particle size of the Al single substance powder is 200 mesh.

[0071] Example 1

[0072] A method for preparing methanol by non-equilibrium plasma synergistic two-step catalysis, the steps are as follows:

[0073] (1) CO2 reduction: the mixed gas I formed by CO2 and H2 is reduced to CO in the dielectric barrier discharge catalytic reactor I, and the generated CO enters the drying device through the connecting pipe and is fully dried;

[0074] (2) Catalytic hydrogenation of CO to methanol

[0075] The mixed gas I obtained in step (1) is fully dried by the condenser and then combined with H2 added from the hydrogen inlet branch to form a mixed gas II, which then enters the dielectric barrier discharge catalytic reactor II for catalytic reaction to obtain methanol.

[0076] The volume ratio of CO2 to H2 in the mixed gas I is 1:3, the total flow rate of the reaction gas in the dielectric barrier discharge catalytic reactor I is 10 SCCM, the gas pressure of the mixed gas I in the dielectric barrier discharge catalytic reactor I is 1.3 bar, the reaction temperature is 60°C, and the residence time of the mixed gas I in the discharge area is 10.6 s.

[0077] The main component of the output gas flowing out of the outlet of the dielectric barrier discharge catalytic reactor I is CO, but the output gas contains a considerable concentration of H2O. The presence of H2O will reduce the activity of the catalyst in the dielectric barrier discharge catalytic reactor II and increase the difficulty of discharge. Therefore, it is necessary to use a drying device (such as the one in the manual) to dry the H2O. Figure 4 As shown in the figure, the dehydration is carried out. The dehydration principle of the drying equipment is to use condensation dehydration (using the ice-water mixture in the dryer to create a low-temperature environment of 0°C), so that the gas obtained by the reaction in the catalytic reactor I is fully dried, and the dried gas flows out of the drying equipment, and then mixed with H2 to form a mixed gas II. In this case, a mass flow meter is used to control the H2 flow rate to achieve a volume ratio of CO to H2 of 1:5. At this time, the total flow rate of the reaction gas is 11SCCM, and the pressure of the mixed gas II in the dielectric barrier discharge catalytic reactor II is about 1.1 bar, and the reaction temperature is controlled to 75°C. The residence time of the mixed gas II in the discharge area should be 49s. A gas chromatograph is used to analyze the volume fraction of gases such as CO2 and methanol in the final gas generated by the reaction for measurement, and a soap film flowmeter is used to calculate the volume of the final generated gas, and the volume of condensed water obtained in the condenser is measured. The calculation formulas for CO2 conversion rate and methanol selectivity are as follows:

[0078]

[0079] Among them, N(CO2) in and N(CO2) out They represent the number of moles of CO2 initially introduced into the reaction and the number of moles of CO2 remaining after the reaction, respectively.

[0080] The selectivity of the product CH3OH is defined as:

[0081]

[0082] Among them, N(CH3OH) out They represent the molar number of CO generated during the reaction. After the reaction, the CO2 conversion rate is as high as 80.15%, and the methanol selectivity reaches 50.83%.

[0083] In order 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.

[0084] Comparative Example 1 is the same as Example 1, except that, in the dielectric barrier discharge catalytic reactor I in Comparative Example 1, the reduction catalyst is first filled along the gas flow direction, and then the metal mixed powder I is filled, the reduction catalyst filling area and the metal mixed powder I filling area are filled alternately, and the number of the reduction catalyst filling areas is 2.

[0085] Comparative Example 2 is the same as Example 1, except that in the dielectric barrier discharge catalytic reactor II in Comparative Example 2, along the gas flow direction, the hydrogenation catalyst is first filled and then the metal mixed powder II is filled, the hydrogenation catalyst filling area and the metal mixed powder II filling area are filled alternately, and the number of hydrogenation catalyst filling areas is 3.

[0086] Comparative Example 3 is the same as Example 1, except that the metal mixed powder I is not filled in the dielectric barrier discharge catalytic reactor I of Comparative Example 3, and the filling length of the reduction catalyst filling area is 15 cm.

[0087] 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.

[0088] Comparative Example 5 is the same as Example 1, except that the metal mixed powder I is not filled in the dielectric barrier discharge catalytic reactor I of Comparative Example 5, and the metal mixed powder II is not filled in the dielectric barrier discharge catalytic reactor 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.

[0089] Comparative Example 6 is the same as Example 1, except that, in the dielectric barrier discharge catalytic reactor I in Comparative Example 6, the filling length of each reduction catalyst filling zone is 2 cm.

[0090] Comparative Example 7 is the same as Example 1, except that, in the dielectric barrier discharge catalytic reactor I in Comparative Example 7, the filling length of each reduction catalyst filling zone is 4 cm.

[0091] Comparative Example 8 is the same as Example 1, except that, in the dielectric barrier discharge catalytic reactor I in Comparative Example 8, the filling length of each reduction catalyst filling zone is 6 cm.

[0092] Comparative Example 9 is the same as Example 1, except that in the dielectric barrier discharge catalytic reactor II in Comparative Example 9, the filling length of each hydrogenation catalyst filling zone is 2 cm.

[0093] Comparative Example 10 is the same as Example 1, except that in the dielectric barrier discharge catalytic reactor II in Comparative Example 10, the filling length of each hydrogenation catalyst filling zone is 4 cm.

[0094] Comparative Example 11 is the same as Example 1, except that in the dielectric barrier discharge catalytic reactor II in Comparative Example 11, the filling length of each hydrogenation catalyst filling zone is 10 cm.

[0095] Comparative Example 12 is the same as Example 1, except that in the metal mixed powder I in the dielectric barrier discharge catalytic reactor I in Comparative Example 12, a mixture of Fe single substance powder and Al single substance powder is formed in a mass ratio of 1:3.

[0096] Comparative Example 13 is the same as Example 1, except that in the metal mixed powder I in the dielectric barrier discharge catalytic reactor I in Comparative Example 13, a mixture of Fe single substance powder and Al single substance powder is formed in a mass ratio of 1:1.

[0097] Comparative Example 14 is the same as Example 1, except that in the metal mixed powder II in the dielectric barrier discharge catalytic reactor II in Comparative Example 14, a mixture of Fe single substance powder and Al single substance powder is formed in a mass ratio of 1:3.

[0098] 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 single substance powder and Al single substance powder in a mass ratio of 1:1.

[0099] The test data of CO2 conversion rate, methanol selectivity, methanol space-time yield, etc. obtained in Example 1 of the present invention and Comparative Examples 1-15 are shown in Table 1.

[0100] Table 1

[0101] Test items <![CDATA[CO2 conversion rate (%)]]> Methanol selectivity (%) Example 1 80.15 50.83 Comparative Example 1 60.47 20.55 Comparative Example 2 70.71 19.64 Comparative Example 3 15.51 20.94 Comparative Example 4 57.39 3.43 Comparative Example 5 36.7 3.64 Comparative Example 6 22.9 12.59 Comparative Example 7 37.1 12.78

[0102] Table 1

[0103] Test items <![CDATA[CO2 conversion rate (%)]]> Methanol selectivity (%) Comparative Example 8 77.17 22.25 Comparative Example 9 68.32 2.36 Comparative Example 10 69.92 32.96 Comparative Example 11 81.67 13.28 Comparative Example 12 53.89 22.32 Comparative Example 13 68.32 23.36 Comparative Example 14 69.92 22.96 Comparative Example 15 73.67 26.28

[0104] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An electrocatalytic reactor device system for catalytic methanol production, characterized in that: The invention comprises a dielectric barrier discharge catalytic reactor I and a dielectric barrier discharge catalytic reactor II, wherein a drying device is arranged between the dielectric barrier discharge catalytic reactor I and the dielectric barrier discharge catalytic reactor II, the dielectric barrier discharge catalytic reactor I is interconnected with the dielectric barrier discharge catalytic reactor II and the drying device through a connecting pipe, a hydrogen inlet branch pipe is also arranged in the middle of the connecting pipe between the dielectric barrier discharge catalytic reactor II and the drying device, and the hydrogen inlet branch pipe is interconnected with the connecting pipe.

2. The electrocatalytic reactor device system for catalytic methanol production according to claim 1, characterized in that: The catalyst loading area of ​​the dielectric barrier discharge catalytic reactor I includes a plurality of reduction catalyst loading areas, and a metal mixed powder I loading area is arranged between adjacent reduction catalyst loading areas; The packing density of the reducing catalyst in the reducing catalyst packing zone is 0.75-1.15 g / mL; The packing density of the metal mixed powder I packing area is 1.5-1.8 g / mL; The ratio of the filling length of a single reduction catalyst filling area to that of a single metal mixed powder I filling area 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 single substance powder and Al single substance powder in a mass ratio of 3:1; The reduction catalyst is γ-Al2O3 particles loaded with two kinds of Fe and Ce nanoparticles.

3. The electrocatalytic reactor device system for catalytic methanol production according to claim 2, characterized in that: The diameter of the γ-Al2O3 particles is 0.5-1.2 mm, the loading amount of Fe on the surface of the γ-Al2O3 particles is 3.5-4.2 wt.%, and the loading amount of Ce on the surface of the γ-Al2O3 particles is 5.5-6.5 wt.%.

4. The electrocatalytic reactor device system for catalytic methanol production according to claim 2, characterized in that: The number of reduction catalyst loading areas shall be no less than 3.

5. The electrocatalytic reactor device system for catalytic methanol production according to claim 1, characterized in that: The catalyst loading area of ​​the dielectric barrier discharge catalytic reactor II includes a plurality of hydrogenation catalyst loading areas and a plurality of metal mixed powder II loading areas, and the catalyst loading areas and the metal mixed powder II loading areas are alternately distributed; The packing density of the hydrogenation catalyst in the hydrogenation catalyst packing area is 0.75-1.15 g / mL; The packing density of the metal mixed powder II in the metal mixed powder II packing area is 1.5-1.8 g / mL; The ratio of the filling length of the single hydrogenation catalyst filling area to the single metal mixed powder II filling area along the axial direction of the dielectric barrier discharge catalytic reactor II is 6-8 cm: 1-2 mm; The hydrogenation catalyst is γ-Al2O3 particles loaded with two kinds of Fe and Cu nanoparticles. The metal mixed powder II is a mixture of Fe single substance powder and Al single substance powder in a mass ratio of 3:

1.

6. The electrocatalytic reactor device system for catalytic methanol production according to claim 5, characterized in that: The diameter of the γ-Al2O3 particles is 0.5-1.2 mm, the loading amount of Fe on the surface of the γ-Al2O3 particles is 3.5-4.2 wt.%, and the loading amount of Cu on the surface of the γ-Al2O3 particles is 7.5-8.5 wt.%.

7. The electrocatalytic reactor device system for catalytic methanol production according to claim 5, characterized in that: The number of hydrogenation catalyst loading areas shall not be less than 4.

8. A method for preparing methanol by non-equilibrium plasma synergistic two-step catalysis, characterized in that: The preparation method comprises the following steps: (1) CO2 reduction: the mixed gas I formed by CO2 and H2 is reduced to CO in the dielectric barrier discharge catalytic reactor I, and the generated CO enters the drying device through the connecting pipe and is fully dried; (2) Catalytic hydrogenation of CO to methanol The mixed gas I obtained in step (1) is fully dried by the condenser and then combined with H2 added from the hydrogen inlet branch to form a mixed gas II, which then enters the dielectric barrier discharge catalytic reactor II for catalytic reaction to obtain methanol.

9. The method for preparing methanol by non-equilibrium plasma synergistic two-step catalysis according to claim 8, characterized in that: 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°C, and the residence time of the mixed gas I in the discharge area should be 7-14s.

10. The method for preparing methanol by non-equilibrium plasma synergistic two-step catalysis according to claim 8, characterized in that: 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°C, and the residence time of the mixed gas II in the discharge area should be 40-50s.

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