Electrification method for preparing CO through carbon reduction of CO2
Through the electrification method of carbon and catalyst, the interface electric heating effect and interface electronic effect are used to achieve efficient conversion of CO2 at low temperature and low energy consumption, solve the problem of high temperature and high energy consumption, reduce the energy consumption of carbon-CO2 gasification reaction, and Use waste charcoal to achieve solid waste utilization.
Patent Information
- Application Number
- CN202411405044.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-01-10
AI Technical Summary
The existing carbon-CO2 gasification reaction requires high temperature and catalyst, which leads to high energy consumption and catalyst sintering, which limits the development of technology and requires exploration of low-temperature and low-energy conversion methods.
By mixing the carbon material with the catalyst and energizing it in the reaction chamber, using the interface electric heating effect and the interface electronic effect, the conversion of CO2 under low temperature conditions is achieved, waste carbon such as biomass is selected as raw materials, and catalysts such as alkali metal salts are used to control the conductivity and electric power to achieve efficient conversion of CO2.
It realizes efficient conversion of CO2 and carbon under low temperature and low energy consumption, reduces energy consumption, improves CO2 conversion rate, and uses waste carbon to achieve solid waste utilization, significantly reducing the energy consumption of carbon-CO2 gasification reaction.
Smart Images
Figure CN119284905A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of carbon capture and utilization, and in particular to an electrification method for producing CO by reducing CO2 with carbon. Background Art
[0002] With the massive consumption of fossil fuels, CO2 emissions are increasing, causing serious environmental problems and energy crises. Therefore, it is urgent to develop CO2 capture, storage and conversion technologies to deal with CO2 emissions. Among them, a direct and effective CO2 utilization technology is to reduce CO2 through carbon, the reaction is as follows: C+CO2→2CO (DH° 298K = 172 kJ / mol), this reaction uses the carbon that is ubiquitous in nature to convert the greenhouse gas CO2 into high-value-added CO, achieving clean and efficient use of fuels, and can effectively alleviate problems such as air pollution caused by the direct combustion of fuels such as coal and biomass.
[0003] However, the CO2 gasification reaction of charcoal is a highly endothermic reaction, which requires the presence of a catalyst and high temperature (>700°C) to proceed. High-temperature reactions will lead to catalyst sintering. At the same time, high-temperature endothermic reactions have high energy consumption, resulting in high process costs and limiting technological development. Therefore, it is necessary to explore unconventional heating systems to meet the challenges of high-temperature charcoal-CO2 gasification reactions. Summary of the invention
[0004] In view of the deficiencies of the prior art, the technical problem to be solved by the present invention is how to achieve efficient conversion of CO2 and charcoal under low temperature and low energy consumption conditions.
[0005] To achieve the above object, the present invention provides an electrification method for producing CO by reducing CO2 with carbon, comprising the following steps: mixing a carbon material with a catalyst to obtain a carbon-catalyst mixture; placing the carbon-catalyst mixture in a reaction chamber and applying electricity to the carbon-catalyst mixture; A reaction gas containing CO2 is introduced into the reaction chamber, and the reaction gas contacts the carbon-catalyst mixture to convert CO2 into CO.
[0006] The present invention utilizes the interface electrothermal effect and the interface electronic effect to promote the CO2 carbon gasification reaction and realize the efficient conversion of CO2 and waste carbon under low temperature and low energy consumption conditions.
[0007] Furthermore, the conductivity of the carbon-catalyst mixture is 10 -3 ~10 4S / m. The electrification reaction is greatly affected by the resistivity of the material. The carbon-CO2 gasification reaction is a gas-solid-solid three-phase catalysis, that is, the carbon will be consumed continuously. The resistivity of the carbon-catalyst mixture will change during the reaction. It is necessary to ensure that the mixture maintains a suitable conductivity during the reaction and can generate sufficient electrothermal effect when current passes through, thereby ensuring the CO2 conversion performance.
[0008] Furthermore, in the step of applying electricity to the carbon-catalyst mixture, the electric power per unit mass of the catalyst is 50-1000 W / g. By controlling the input of electric power, CO2 and carbon can be converted into high-value CO at low power. Since the carbon material will be consumed during the reaction, the unit mass of the catalyst is used as the basis for determining the electric power.
[0009] Furthermore, the carbon material is selected from one or more pyrolysis products of biomass, coal, petroleum coke, urban solid waste, plastic, sewage sludge, etc. Selecting waste carbon as the reaction raw material has low material cost and realizes solid waste utilization.
[0010] Furthermore, the catalyst is selected from at least one of alkali metal salts, alkaline earth metal salts, and transition metal salts. The selection of a catalyst with catalytic oxidation ability can help improve the CO2 conversion efficiency.
[0011] Furthermore, the volume fraction of CO2 in the reaction gas is 1% to 100%. By controlling the volume fraction of CO2 in the reaction gas, the selectivity of CO2 can be improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is a relationship diagram of the maximum CO2 conversion rate, CO production per unit energy consumption and CO2 concentration in Example 1 of the present invention.
[0013] Figure 2 This is a relationship diagram of the maximum CO2 conversion rate, CO production per unit energy consumption and CO2 concentration in Example 4 of the present invention.
[0014] Figure 3 This is a comparison chart of CO production per unit energy consumption of Example 4 of the present invention and Comparative Example 1. DETAILED DESCRIPTION
[0015] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.
[0016] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.
[0017] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.
[0018] A specific embodiment of the present invention provides an electrification method for producing CO by reducing CO2 with carbon, comprising the following steps: S1. Mix the carbon material and the catalyst to obtain a carbon-catalyst mixture. In a specific embodiment, the carbon material used can be selected from the pyrolysis products of biomass, coal, petroleum coke, urban solid waste, plastic, sewage sludge and the like, and the catalyst can be selected from alkali metal salts, alkaline earth metal salts, transition metal salts and the like. The conductivity of the carbon-catalyst mixture is controlled to be 10 -3 ~10 4 S / m.
[0019] S2, placing the carbon-catalyst mixture in a reaction chamber, and applying electricity to the carbon-catalyst mixture. In a specific embodiment, the electric power per unit mass of the catalyst is used as a basis for determining the electric power, and the electric power per unit mass of the catalyst is controlled to be 50-1000 W / g.
[0020] S3, introducing a reaction gas containing CO2 into the reaction chamber, and the reaction gas contacts the carbon-catalyst mixture to convert CO2 into CO. In a specific embodiment, the volume fraction of CO2 in the reaction gas is 1% to 100%.
[0021] The above-mentioned electrification method does not require an external heat source. By controlling the input of electric power and utilizing the interfacial electrothermal effect and interfacial electronic effect, CO2 and char can be converted into high-value CO under low-temperature and low-energy conditions.
[0022] The technical solutions and effects of the present invention are further described below in conjunction with specific embodiments.
[0023] Example 1
[0024] Potassium carbonate was used as the catalyst and carbon black as the carbon source. The catalyst and the carbon source were ball-milled and mixed (mass ratio of potassium carbonate / carbon smoke = 1:1) and then sieved to 40-60 mesh. 0.15 g of sample was placed in the reaction chamber, and a mixed reaction gas of CO2 and N2 was introduced at a flow rate of 100 mL / min. The target power was input at 12 W. The reaction gas with a volume fraction of CO2 of 1%, 3%, 5%, 10%, 15%, 20%, and 100% was analyzed respectively. The airflow after the reaction entered the online flue gas analyzer for quantitative analysis. The results are shown in the figure. Figure 1 When the reaction gas is CO2 / N2 (5% / 95%), the CO production per unit energy consumption is 395.91μmol / kJ, and the maximum CO2 conversion rate is 97.97%; when the reaction gas is CO2 / N2 (10% / 90%), the CO production per unit energy consumption is 552.59μmol / kJ, and the maximum CO2 conversion rate is 92.60%.
[0025] Example 2
[0026] Sodium carbonate was used as the catalyst and carbon black as the carbon source. The catalyst and the carbon source were ball-milled and mixed (sodium carbonate / carbon soot mass ratio = 1:1) and then sieved to 40-60 mesh. 0.15g of sample was placed in the reaction chamber, and the reaction gas 100mL / min CO2 / N2 (5% / 95%) was introduced. The target power was 12 W, and the airflow after the reaction entered the online flue gas analyzer for analysis. The results showed that the CO production per unit energy consumption was 707.06μmol / kJ, and the maximum CO2 conversion rate reached 89.15%.
[0027] Example 3
[0028] Potassium carbonate was used as the catalyst and carbon black as the carbon source. After the catalyst and the carbon source were ball-milled and mixed (mass ratio of potassium carbonate / carbon smoke = 1:2), they were sieved to 40-60 mesh, and the reaction gas 100mL / min CO2 / N2 (5% / 95%) was introduced. The target power was 12W, and the airflow after the reaction was analyzed by an online flue gas analyzer. The results showed that the CO production per unit energy consumption was 369.66μmol / kJ, and the maximum CO2 conversion rate reached 95.10%.
[0029] Example 4
[0030] Potassium carbonate was used as the catalyst and carbon black as the carbon source. The catalyst and carbon source were ball-milled and mixed (mass ratio of carbonate: carbon black = 1:1) and then sieved to 40-60 mesh. 0.15g of sample was placed in the reaction chamber, and the reaction gas 100mL / min CO2 / N2 (5% / 95%) was introduced. Different target powers were input for analysis, and the target powers were 8W, 10W, 12W, 14W, 16W, and 18W respectively. The airflow after the reaction entered the online flue gas analyzer for analysis. The results are as follows: Figure 2When the input target power is 14 W, the CO production per unit energy consumption is 423.03 μmol / kJ, and the maximum CO2 conversion rate reaches 97.76%.
[0031] Comparative Example 1 Potassium carbonate was used as a catalyst and carbon black was used as a carbon source. The catalyst and the carbon source were ball-milled and mixed (mass ratio of carbonate: soot = 1:1) and then sieved to 40-60 mesh. 0.15 g of the sample was placed in a reaction chamber, and a reaction gas of 100 mL / min CO2 / N2 (5% / 95%) was introduced. The reaction was carried out at a constant temperature of 900 °C, and the gas flow after the reaction entered an online flue gas analyzer for analysis. The result was that the CO production per unit energy consumption was 9.22 μmol / kJ, and the maximum CO2 conversion rate reached 95.58%. Comparing the CO production per unit energy consumption of Example 4 with that of Comparative Example 1, the results are as follows: Figure 3 As shown, it can be seen that the electrification method of the present invention can significantly reduce the energy consumption of the CO2 gasification reaction of charcoal.
[0032] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.
Claims
1. An electrification method for producing CO by reducing CO2 with carbon, characterized in that: The following steps are involved: mixing a carbon material with a catalyst to obtain a carbon-catalyst mixture; placing the carbon-catalyst mixture in a reaction chamber and applying electricity to the carbon-catalyst mixture; A reaction gas containing CO2 is introduced into the reaction chamber, and the reaction gas contacts the carbon-catalyst mixture to convert CO2 into CO.
2. The electrification method for producing CO by reducing CO2 with carbon according to claim 1, characterized in that: The conductivity of the carbon-catalyst mixture is 10 -3 ~10 4 S / m.
3. The electrification method for producing CO by reducing CO2 with carbon according to claim 1, characterized in that: In the step of applying electricity to the carbon-catalyst mixture, the electric power per unit mass of the catalyst is 50-1000 W / g.
4. The electrification method for producing CO by reducing CO2 with carbon according to any one of claims 1 to 3, characterized in that: The catalyst is selected from at least one of alkali metal salts, alkaline earth metal salts and transition metal salts.
5. The electrification method for producing CO by reducing CO2 with carbon according to any one of claims 1 to 3, characterized in that: The carbon material is selected from one or more pyrolysis products of biomass, coal, petroleum coke, urban solid waste, plastic, and sewage sludge.
6. The electrification method for producing CO by reducing CO2 with carbon according to any one of claims 1 to 3, characterized in that: The volume fraction of CO2 in the reaction gas is 1%~100%.