A method for the complete reduction of carbon dioxide to carbon monoxide

Abstract

The present application relates to carbon monoxide production technical field, specifically to a kind of carbon dioxide is fully reduced to carbon monoxide method, reaction gas is passed into plasma reactor, the reaction gas is the mixed gas of low carbon hydrocarbon gas and carbon dioxide, dry reforming reaction and reverse steam shift reaction are coupled by thermal plasma medium, carbon dioxide is reduced to carbon monoxide by low carbon hydrocarbon gas.The conversion rate of the present application methane is 99%;Carbon dioxide conversion rate is 85~95%;Carbon monoxide selectivity is >99%;No carbon deposition;Carbon monoxide concentration in tail gas can reach 80%, and main byproduct is water, more conducive to separation and purification;The present application also has the characteristics such as product easy separation, process repeatability, operation safety and reliability, and has broad industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon monoxide production, in particular to a method for fully reducing carbon dioxide into carbon monoxide. BACKGROUND

[0002] Carbon monoxide is an important product of carbon dioxide conversion, and its downstream products include methanol, acetic acid, acrylic acid, and other liquid fuels and high-value-added oxygen-containing compounds. At the same time, the downstream conversion of carbon monoxide can directly use existing coal chemical and natural gas chemical technology and equipment, facilitating technology integration.

[0003] The traditional chemical reaction for reducing carbon dioxide into carbon monoxide is dry reforming. As early as 1928, Fischer and Tropsch proposed using dry reforming to produce carbon monoxide and hydrogen (i.e., synthesis gas) for Fischer-Tropsch synthesis. In the past few decades, dry reforming catalysts have made great progress. However, dry reforming catalysts always face the problem of strong carbon deposition and sintering. Therefore, additional water needs to be added in the existing dry reforming process to maintain the reaction for a long time, ultimately resulting in a carbon dioxide / methane ratio less than 1. On the other hand, the temperature of the thermal catalytic dry reforming reaction is generally 700-800°C, and if this part of the heat is obtained by burning fossil energy, the amount of carbon dioxide produced will be much greater than the amount consumed by dry reforming, which obviously contradicts the original intention of carbon reduction.

[0004] Thermal plasma is an excellent high-energy reaction medium, characterized by high temperature, high enthalpy, and extremely fast reaction speed. Thermal plasma dry reforming can overcome the need to add water in traditional thermal catalysis and eliminate the problem of catalyst carbon deposition. At the same time, plasma reaction is driven by electricity. In the context of the increasing proportion of green energy, thermal plasma is more practical for carbon reduction and sequestration. Domestic researchers have initially achieved the reduction and conversion of carbon dioxide into synthesis gas using thermal plasma dry reforming. Patent (CN 114733477A) proposes a coupling of thermal plasma and catalyst to achieve plasma-catalytic coupling reforming. Since a dry reforming catalyst is used, there is still a small amount of carbon deposition in this patent, and the carbon dioxide / methane ratio is not very flexible, always around 1. Patent (CN 113272246A) provides a thermal plasma reforming process without the use of inert shielding gas, but a large amount of carbon deposition occurs in the product, and the selectivity of carbon monoxide is low.

[0005] Further improving the utilization rate of methane molecules in the thermal plasma carbon dioxide-methane reduction reaction, reducing the subsequent separation cost, and reducing or even eliminating carbon deposition are key issues for the development of this technology. SUMMARY

[0006] The application aims to provide a method for fully reducing carbon dioxide into carbon monoxide, and solve the technical problems of low utilization rate of methane molecules and high cost of subsequent separation in the hot plasma carbon dioxide-methane reduction reaction in the prior art.

[0007] The application discloses a method for fully reducing carbon dioxide into carbon monoxide, and comprises the following steps: passing a reaction gas into a plasma reactor, wherein the reaction gas is a mixed gas of low-carbon hydrocarbon gas and carbon dioxide; coupling a dry reforming reaction and a reverse water gas shift reaction by a hot plasma medium; and reducing the carbon dioxide into carbon monoxide by the low-carbon hydrocarbon gas.

[0008] Further, the hot plasma heat supply is realized by a plasma generation module, the plasma type is direct current arc plasma, the voltage range is 55-1200V, and the current range is 50-1000A.

[0009] Further, the cathode working gas of the direct current arc plasma is one or a combination of more than two of Ar, He, CH4, CO2, CO and H2.

[0010] Further, the material of the discharge module of the direct current arc plasma is one or a combination of more than two of copper, iron, zirconium, tungsten and graphite.

[0011] Further, the discharge electrode of the direct current arc plasma is one or a combination of more than two of copper, tungsten and graphite.

[0012] Further, the material of the reaction module of the direct current arc plasma is one or two of stainless steel, iron, zirconium, tungsten, graphite, copper and alloy.

[0013] Further, the low-carbon hydrocarbon gas comprises methane or C2-C5 hydrocarbon.

[0014] Further, the volume ratio of the carbon dioxide / low-carbon hydrocarbon gas is 2.5-4.0, preferably 2.5-3.5.

[0015] Further, the volume flow ratio of the cathode protection gas to the reaction gas in the reaction is 0.5-5, preferably 1.5-3.5, the reaction pressure is 0.1MPa-1.0MPa, preferably 0.1MPa-0.4MPa.

[0016] Further, the residence time of the reaction gas in the reactor is 5-15ms.

[0017] Further, the oxygen volume content in the plasma reactor during the reaction is less than 0.2%.

[0018] Compared with the prior art, the application has the beneficial effects that:

[0019] 1. The present application provides a method for reducing carbon dioxide to carbon monoxide using methane. The advantage is that the dry reforming reaction and the reverse water gas shift reaction are coupled through a hot plasma medium, taking advantage of the high thermal efficiency and millisecond residence time of thermal plasma reforming, to achieve the reduction of carbon dioxide to carbon monoxide at a high carbon dioxide / methane ratio, while significantly suppressing carbon deposition.

[0020] 2. Increasing the CO2 / CH4 ratio, i.e. increasing the molecular utilization rate of methane, traditional thermal catalytic reduction of one molecule of methane can only reduce 0.6-0.8 molecules of carbon dioxide. One molecule of methane can reduce 3 molecules of carbon dioxide in the present application. When CO2 / CH4 reaches 2.5-3, the CO concentration in the reaction product can reach more than 65%, and the remaining product is water. If high-purity CO is the target, the separation cost can be significantly reduced.

[0021] 3. The conversion rate of methane in the present application is 99%, the conversion rate of carbon dioxide is 85-95%, the selectivity of carbon monoxide is >99%, there is no carbon deposition, the concentration of carbon monoxide in the tail gas can reach 80%, and the main byproduct is water, which is more conducive to separation and purification. The present application also has the characteristics of easy separation of products, good process repeatability, safe and reliable operation, etc., and has a broad industrial application prospect. DETAILED DESCRIPTION

[0022] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments.

[0023] The plasma reactor used in the present application is composed of a discharge module, a reaction module, a regenerative furnace and a circulating water cooling system. The plasma working carrier gas (i.e. cathode protection gas) first enters the discharge module to form a plasma jet, and then the reaction gas enters the reaction module to mix with the jet and react. The reaction tail gas is cooled and gas-liquid separated, and then enters the buffer tank for sampling and analysis. The calculation method of conversion rate and selectivity mentioned in this paper is the same as that of the patent (CN 114733477A).

[0024] Example 1

[0025] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 50A, input power is 7.5kW, cathode protection gas 24L / min; Ar+H2(5:5); the reaction mixed gas is 12L / min CH4 and 18L / min CO2, keep 15 minutes and then start sampling analysis, the analysis results show that the conversion rate of methane is 98%, the conversion rate of carbon dioxide is 93%, the CO selectivity is 99%, CO / H2=0.95.

[0026] Example 2

[0027] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 50A, input power is 7.5kW, cathode protection gas 24L / min; Ar+H2(7:3); the reaction mixed gas is 12L / min CH4 and 18L / min CO2, keep 15 minutes and then start sampling analysis, the analysis results show that the conversion rate of methane is 89%, the conversion rate of carbon dioxide is 83%, the CO selectivity is 95%, CO / H2=0.95.

[0028] Example 3

[0029] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 50A, input power is 8.0kW, cathode protection gas 24L / min; Ar+H2(3:7); the reaction mixed gas is 12L / min CH4 and 18L / min CO2, keep 15 minutes and then start sampling analysis, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 95%, the CO selectivity is 99%, CO / H2=0.98.

[0030] Example 4

[0031] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 60A, input power is 8.7kW, cathode protection gas 24L / min; Ar+H2(1:9); the reaction mixture gas is 12L / min CH4 and 18L / min CO2, keep 15 minutes and then start sampling analysis, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 95%, the CO selectivity is 99%, CO / H2=1.0.

[0032] Example 5

[0033] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 65A, input power is 8.5kW, cathode protection gas 24L / min; pure H2; the reaction mixture gas is 12L / min CH4 and 18L / min CO2, keep 15 minutes and then start sampling analysis, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 95%, the CO selectivity is 99%, CO / H2=1.0.

[0034] Example 6

[0035] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 65A, input power is 8.5kW, cathode protection gas 24L / min; Ar+H2(1:9); the reaction mixture gas is 20L / min CH4 and 30L / min CO2, keep 15 minutes and then start sampling analysis, the analysis results show that the conversion rate of methane is 95%, the conversion rate of carbon dioxide is 87%, the CO selectivity is 99%, CO / H2=1.02.

[0036] Example 7

[0037] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 65A, input power is 8.5kW, cathode protection gas 30L / min; Ar+H2(1:9); the reaction mixed gas is 20L / min CH4 and 30L / min CO2, keep 15 minutes and then start sampling analysis, the analysis result shows that the conversion rate of methane is 94%, the conversion rate of carbon dioxide is 85%, the CO selectivity is 99%, CO / H2=1.0.

[0038] Example 8

[0039] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 50A, input power is 7.5kW, cathode protection gas 24L / min; Ar+H2(5:5); the reaction mixed gas is 15L / min CH4 and 15L / min CO2, keep 15 minutes and then start sampling analysis, the analysis result shows that the conversion rate of methane is 95%, the conversion rate of carbon dioxide is 90%, the CO selectivity is 95%, CO / H2=0.89.

[0040] Example 9

[0041] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 55A, input power is 7.5kW, cathode protection gas 24L / min; Ar+H2(1:1); the reaction mixed gas is 18L / min CH4 and 20L / min CO2, keep 15 minutes and then start sampling analysis, the analysis result shows that the conversion rate of methane is 95%, the conversion rate of carbon dioxide is 95%, the CO selectivity is 89%, CO / H2=0.75.

[0042] Example 10

[0043] A method for reducing carbon dioxide to carbon monoxide, the plasma reactor uses graphite discharge module and reaction module, the discharge electrode is tungsten metal, 5L / min Ar gas and vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 55A, input power 7.5kW, cathode protection gas 24L / min; Ar+H2(1:1); the reaction mixed gas is 21L / min CH4 and 9L / min CO2, sampling analysis is started after 15 minutes, and the analysis results show that the conversion rate of methane is 89%, the conversion rate of carbon dioxide is 99%, the CO selectivity is 80%, and CO / H2=0.76.

[0044] Example 11

[0045] A method for reducing carbon dioxide to carbon monoxide, the plasma reactor uses graphite discharge module and reaction module, the discharge electrode is tungsten metal, 5L / min Ar gas and vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 55A, input power 7.5kW, cathode protection gas 24L / min; Ar+H2(1:1); the reaction mixed gas is 21L / min CH4 and 9L / min CO2, sampling analysis is started after 15 minutes, and the analysis results show that the conversion rate of methane is 89%, the conversion rate of carbon dioxide is 99%, the CO selectivity is 80%, and CO / H2=0.76.

[0046] Example 12

[0047] A method for reducing carbon dioxide to carbon monoxide, the plasma reactor uses graphite discharge module and reaction module, the discharge electrode is tungsten metal, 5L / min Ar gas and vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 55A, input power 7.5kW, cathode protection gas 24L / min; Ar+H2(1:1); the reaction mixed gas is 21L / min CH4 and 9L / min CO2, sampling analysis is started after 15 minutes, and the analysis results show that the conversion rate of methane is 89%, the conversion rate of carbon dioxide is 99%, the CO selectivity is 80%, and CO / H2=0.76.

[0048] Example 13

[0049] A method for reducing carbon dioxide to carbon monoxide, the plasma reactor uses graphite discharge module and reaction module, the discharge electrode is tungsten metal, 5L / min Ar gas and vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 75A, input power 9.5kW, cathode protection gas 24L / min; Ar+H2(1:9); the reaction mixed gas is 10L / min CH4 and 30L / min CO2, sampling analysis is started after 15 minutes, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 83%, the CO selectivity is 99%, the hydrogen selectivity is 0%, and the CO outlet concentration is 43.6%.

[0050] Example 14

[0051] A method for reducing carbon dioxide to carbon monoxide, the plasma reactor uses graphite discharge module and reaction module, the discharge electrode is tungsten metal, 5L / min Ar gas and vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 75A, input power 9.5kW, cathode protection gas 24L / min; Ar+H2(1:9); the reaction mixed gas is 10L / min CH4 and 30L / min CO2, sampling analysis is started after 15 minutes, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 83%, the CO selectivity is 99%, the hydrogen selectivity is 0%, and the CO outlet concentration is 43.6%.

[0052] Example 15

[0053] A method for reducing carbon dioxide to carbon monoxide, the plasma reactor uses graphite discharge module and reaction module, the discharge electrode is tungsten metal, 5L / min Ar gas and vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 75A, input power 9.5kW, cathode protection gas 24L / min; Ar+H2(1:9); the reaction mixed gas is 10L / min CH4 and 30L / min CO2, sampling analysis is started after 15 minutes, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 83%, the CO selectivity is 99%, the hydrogen selectivity is 0%, and the CO outlet concentration is 43.6%.

[0054] Example 17

[0055] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 80A, input power is 10.5kW, cathode protection gas 24L / min; CO2+H2(1:1); the reaction mixed gas is 7L / min CH4 and 11L / min CO2, keep 15 minutes and then start sampling analysis, the analysis result shows that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 87%, the CO selectivity is 92%, the hydrogen selectivity is 5%, and the CO outlet concentration is 61%.

[0056] Example 18

[0057] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 75A, input power is 9.5kW, cathode protection gas 24L / min; CO2+H2(3:1); the reaction mixed gas is 7L / min CH4 and 5L / min CO2, keep 15 minutes and then start sampling analysis, the analysis result shows that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 93%, the CO selectivity is 90%, the hydrogen selectivity is 2%, and the CO outlet concentration is 65%.

[0058] Example 19

[0059] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses graphite discharge module and reaction module, discharge electrode is metal tungsten, using 5L / min Ar gas and vacuum pump to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; adjust the plasma parameters: input current 80A, input power is 10kW, cathode protection gas 24L / min; CO2+CH4(5:1); the reaction mixed gas is 4L / min CH4 and 4L / min CO2, keep 15 minutes and then start sampling analysis, the analysis result shows that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 95%, the CO selectivity is 96%, the hydrogen selectivity is 1%, and the CO outlet concentration is 60%.

[0060] Example 20

[0061] A method for reducing carbon dioxide to carbon monoxide, a plasma reactor uses a graphite discharge module and a reaction module, the discharge electrode is a copper-tungsten alloy, 5L / min Ar gas and a vacuum pump are used to replace the air in the reactor, so that the oxygen volume content in the system is less than 0.2%; the plasma parameters are adjusted as follows: input current 85A, input power 11.5kW, cathode protection gas 24L / min; CO2+CH4(5:1); the reaction mixed gas is 7L / min CH4 and 12L / min CO2, sampling and analysis are started after 15 minutes of keeping, the analysis results show that the conversion rate of methane is 99%, the conversion rate of carbon dioxide is 95%, the CO selectivity is 97%, the hydrogen selectivity is 1%, and the CO outlet concentration is 63%.

[0062] In conclusion, the present application uses hot plasma to reduce carbon dioxide to carbon monoxide by using methane, the methane conversion rate is 90% to 99%, the carbon dioxide conversion rate is 83 to 98%, the CO selectivity is >96%, the outlet CO concentration can reach more than 60%, and no carbon deposition is observed.

[0063] Therefore, it is concluded that the present application realizes the coupling of dry reforming reaction and reverse water gas shift reaction by using hot plasma to reduce carbon dioxide to carbon monoxide. The carbon dioxide / methane ratio can break through the limitation of traditional dry reforming reaction and reach more than 3.0. The present application has the characteristics of high molecular utilization rate, high product selectivity, high tail gas carbon monoxide concentration, easy separation and purification, and high operation reliability, and has broad application potential.

[0064] The above is the implementation mode listed in the present embodiment, but the present embodiment is not limited to the above optional implementation mode, and those skilled in the art can obtain other various implementation modes by arbitrarily combining the above modes with each other, and anyone can obtain other various forms of implementation modes under the inspiration of the present embodiment. The above specific implementation mode should not be understood as a limitation on the protection scope of the present embodiment, and the protection scope of the present embodiment should be defined by the claims, and the specification can be used to explain the claims.

Claims

1. A method for fully reducing carbon dioxide to carbon monoxide, characterized in that: The process includes the following steps: introducing a reaction gas into two reaction modules of the reaction device, wherein the reaction gas is a mixture of low-carbon hydrocarbon gas and carbon dioxide, wherein the volume ratio of carbon dioxide to low-carbon hydrocarbon gas is greater than 1; coupling the dry reforming reaction and the reverse water-gas shift reaction through a thermal plasma medium; and using the low-carbon hydrocarbon gas to reduce carbon dioxide to carbon monoxide.

2. The method for fully reducing carbon dioxide to carbon monoxide according to claim 1, characterized in that: The thermal plasma heating is achieved through a plasma generation module. The plasma type is DC arc plasma, with a voltage range of 55-1200 V and a current range of 50-1000 A.

3. The method for fully reducing carbon dioxide to carbon monoxide according to claim 2, characterized in that: The cathode working gas of the aforementioned DC arc plasma is one or a combination of two or more of Ar, He, CH4, CO2, CO, and H2.

4. The method for fully reducing carbon dioxide to carbon monoxide according to claim 2, characterized in that: The discharge module of the DC arc plasma is made of one or more of the following materials: copper, iron, zirconium, tungsten, and graphite.

5. The method for fully reducing carbon dioxide to carbon monoxide according to claim 2, characterized in that: The discharge electrode of the DC arc plasma is one or a combination of two or more of copper, tungsten, and graphite.

6. The method for fully reducing carbon dioxide to carbon monoxide according to claim 2, characterized in that: The reaction module material of the DC arc plasma is one or two of stainless steel, iron, zirconium, tungsten, graphite, copper, and alloys.

7. The method for fully reducing carbon dioxide to carbon monoxide according to claim 1, characterized in that: The low-carbon hydrocarbon gases include methane or C2-C5 hydrocarbons.

8. The method for fully reducing carbon dioxide to carbon monoxide according to claim 1, characterized in that: The volume ratio of carbon dioxide to low-carbon hydrocarbon gases is 2.5-4.

0.

9. A method for fully reducing carbon dioxide to carbon monoxide according to claim 8, characterized in that: The volume ratio of carbon dioxide to low-carbon hydrocarbon gases is 2.5-3.

5.

10. A method for fully reducing carbon dioxide to carbon monoxide according to claim 1, characterized in that: The volumetric flow rate ratio of the cathodic protection gas to the reaction gas is 0.5~5, and the reaction pressure is 0.1 MPa~1.0 MPa.

11. A method for fully reducing carbon dioxide to carbon monoxide according to claim 10, characterized in that: The volumetric flow rate ratio of cathodic protection gas to reactant gas in the reaction is 1.5~3.5, and the reaction pressure is 0.1 MPa~0.4 MPa.

12. The method for fully reducing carbon dioxide to carbon monoxide according to claim 1, characterized in that: The residence time of the reactant gas in the reactor is 5-15 ms.