Carbon dioxide capture system

Abstract

A carbon dioxide capture system according to an embodiment of the present invention may comprise: a combustor that produces carbon dioxide and water from carbon monoxide and hydrogen contained in a mixed gas; a moisture remover that removes moisture contained in a mixed gas obtained from the combustor; and a carbon dioxide separator that obtains carbon dioxide from a mixed gas obtained from the moisture remover.

Description

carbon dioxide capture system

[0001] The present invention relates to a carbon dioxide capture system.

[0002] As industries develop and the population grows globally, the demand for iron is increasing, and consequently, the use of fossil fuels to supply the energy and raw materials for iron production is also rising.

[0003] The steel industry is a major emitter of greenhouse gases, and is actively developing technologies to produce low-carbon steel products for carbon neutrality. For example, carbon capture and storage (CCUS) technology is being incorporated into blast furnace operations and FINEX processes to significantly reduce carbon intensity (tCO2 / tCS).

[0004] Nevertheless, there are difficulties in commercialization due to carbon capture technology, which accounts for more than 60% of the cost of introducing CCUS technology.

[0005] If an absorption process is applied to selectively recover carbon dioxide from byproduct gas, energy must be input into the carbon dioxide absorption / regeneration facility, and if an adsorption process is applied, energy is consumed for gas pressurization. In addition, capture costs are incurred due to the consumed energy, with a capture cost of approximately 300,000 won per ton, and these high capture costs are hindering the widespread adoption of carbon dioxide capture technology.

[0006] Therefore, the issue is how to capture carbon dioxide at a low cost.

[0007] One embodiment of the present invention can provide a carbon dioxide capture system capable of removing carbon monoxide contained in byproduct gas.

[0008] One embodiment of the present invention can provide a carbon dioxide capture system capable of capturing carbon dioxide contained in byproduct gas at a low cost.

[0009] One embodiment of the present invention can provide a carbon dioxide capture system capable of producing liquefied carbon dioxide from carbon dioxide contained in byproduct gas.

[0010]

[0011] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0012] A carbon dioxide capture system according to one embodiment of the present invention comprises: a combustor that generates carbon dioxide and water from carbon monoxide and hydrogen contained in a mixed gas; a moisture remover that removes moisture contained in the mixed gas obtained from the combustor; and a carbon dioxide separator that obtains carbon dioxide from the mixed gas obtained from the moisture remover.

[0013] The above combustion device may include an oxidation catalyst.

[0014] The above oxidation catalyst may include Pt / Al2O3.

[0015] The above oxidation catalyst may further include at least one selected from the group consisting of Co3O4 and Co / Al2O3.

[0016] The heating temperature of the above combustion device may be 100 to 300°C.

[0017] The above combustion device may further include a heat exchanger that recovers the carbon monoxide oxidation reaction array.

[0018] The above mixed gas may be a gas derived from byproduct gas.

[0019] The above byproduct gas may be at least one selected from the group consisting of BFG (Blast Furnace Gas), COG (Coke Oven Gas), LDG (Linz-Donawitz Gas), FOG (Fuel Oil Gas) and FTG (Flare Tower Gas).

[0020] The above moisture remover may include at least one selected from the group consisting of moisture adsorbents and moisture absorbents.

[0021] The above carbon dioxide separator may include a cryogenic separator.

[0022] A carbon dioxide capture system, which is an embodiment of the present invention, can remove carbon monoxide contained in byproduct gas.

[0023] A carbon dioxide capture system, which is an embodiment of the present invention, can capture carbon dioxide contained in byproduct gas at a low cost.

[0024] A carbon dioxide capture system, which is an embodiment of the present invention, can produce liquefied carbon dioxide from carbon dioxide contained in byproduct gas.

[0025] FIG. 1 is a diagram illustrating an exemplary carbon dioxide capture system, which is an embodiment of the present invention.

[0026] FIG. 2 is a photograph exemplarily showing an oxidation catalyst included in a combustion device in one embodiment of the present invention.

[0027] Figure 3 is a graph showing the carbon monoxide conversion rate according to the type of oxidation catalyst included in the combustion chamber in one embodiment of the present invention.

[0028] Figure 4 is a graph showing the hydrogen conversion rate according to the type of oxidation catalyst included in the combustion chamber in one embodiment of the present invention.

[0029] Figure 5 is a graph showing the temperature rise with respect to the amount of oxidation catalyst (oxidizer) added to the combustion chamber in one embodiment of the present invention.

[0030] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0031] In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field.

[0032] In drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0033] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0034] In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0035] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0036] In this specification, terms such as 'top', 'upper', 'upper surface', 'lower', 'lower surface', 'lower surface', and 'side surface' are based on the drawings and may actually vary depending on the direction in which the elements or components are arranged.

[0037] Additionally, throughout the specification, when it is said that one part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between.

[0038] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0039] One embodiment of the present invention can provide a carbon dioxide capture system capable of removing carbon monoxide contained in byproduct gas, capturing carbon dioxide contained in byproduct gas at a low cost, and producing liquefied carbon dioxide from carbon dioxide.

[0040] FIG. 1 is a diagram illustrating an exemplary carbon dioxide capture system, which is an embodiment of the present invention.

[0041] Referring to FIG. 1, a carbon dioxide capture system of one embodiment of the present invention may include a combustor (100) that generates carbon dioxide and water from carbon monoxide and hydrogen contained in a mixed gas; a moisture remover (200) that removes moisture contained in the byproduct gas obtained from the combustor (100); and a carbon dioxide separator (300) that obtains carbon dioxide from the byproduct gas obtained from the moisture remover (200).

[0042] In one embodiment of the present invention, the combustor (100) may be configured to oxidize carbon monoxide contained in the mixed gas to produce carbon dioxide. The carbon monoxide oxidation reaction in the combustor (100) is as follows and Equation (1).

[0043] [Equation (1)]

[0044] CO + H2 + O2 → CO2 + H2O

[0045] The above mixed gas may be a gas derived from a byproduct gas, and the above byproduct gas may be a steel byproduct gas, and specifically, it may be at least one selected from the group consisting of BFG (Blast Furnace Gas), COG (Coke Oven Gas), LDG (Linz-Donawitz Gas), FOG (Fuel Oil Gas), FTG (Flare Tower Gas), etc.

[0046] The approximate major components contained in the above byproduct gas are shown in Table 1 below.

[0047] Content of major components (Moll%) CO2COH2CH4N2BFG20203-54COG3856272LDG18642-16FOG333615-11FTG60~7010~20~5-~10

[0048] As shown in Table 1 above, since steel byproduct gas contains CO, high-purity carbon dioxide can be obtained by oxidizing it. The combustion device (100) above may include an oxidation catalyst, and while the temperature required for the carbon monoxide oxidation reaction is generally 300°C or higher, the reaction temperature can be significantly lowered when carbon monoxide is oxidized with an oxidation catalyst, thereby saving energy.

[0049] The oxidation catalyst may include Pt / Al2O3 and may further include at least one selected from the group consisting of Co3O4 and Co / Al2O3. The combustion device (100) including the oxidation catalyst may have a conversion rate of CO and H2 of 99% or more at a temperature of about 250°C, specifically 99.9% or more. Additionally, the combustion device (100) including the oxidation catalyst may have a conversion rate of CO and H2 of 99% or more at a temperature of about 100°C, specifically 99.9% or more.

[0050] FIG. 2 is a photograph exemplarily showing an oxidation catalyst included in a combustor (100) in one embodiment of the present invention. Referring to FIG. 2, exemplarily, the oxidation catalyst may be used by coating the oxidation catalyst on the surface of a metal mesh inside a cylindrical pipe.

[0051] The above oxidation catalyst is not particularly limited, but, for example, can be introduced in an amount of 0.1 to 9 L / min. As the content of the oxidation catalyst decreases, the temperature rise of the combustion chamber (100) decreases, but the oxidation reaction may be slowed down, and as the content of the oxidation catalyst increases, the oxidation reaction is faster, but the temperature rise of the combustion chamber (100) may increase.

[0052] In the above equation (1), the molar ratio of the reactants hydrogen, oxygen, and carbon monoxide is 1:1:1, so additional gas that is insufficient for the carbon monoxide oxidation reaction can be supplied to the combustion device (100).

[0053] The mixed gas discharged from the above combustion device (100) may include carbon dioxide and steam (water), and may additionally include nitrogen, unreacted carbon monoxide, oxygen, hydrogen, etc.

[0054] The heating temperature of the combustion device (100) may be 100 to 300°C, specifically 150 to 200°C. If the heating temperature of the combustion device (100) is less than 100°C, the carbon monoxide oxidation reaction may not occur properly, and if it exceeds 300°C, excessive energy may be input.

[0055] The carbon monoxide oxidation reaction of the above equation (1) is an exothermic reaction, and heat may be generated depending on the reaction. Accordingly, the above combustion device (100) may further include a heat exchanger for recovering the heat from the carbon monoxide oxidation reaction. Low-temperature steam may be introduced into the above combustion device (100), and high-temperature steam may be discharged. The combustion device (100) including the above heat exchanger can save energy by recovering waste heat and can prevent corrosion caused by high temperatures.

[0056] In one embodiment of the present invention, the moisture remover (200) may be configured to remove moisture contained in the mixed gas obtained from the combustor (100). By removing moisture from the mixed gas, a high concentration of carbon dioxide can be obtained.

[0057] The above moisture remover (200) may include at least one selected from the group consisting of a moisture adsorbent and a moisture absorbent. The moisture adsorbent may include, for example, activated carbon, silica gel, zeolite, etc. The moisture absorbent may include TEG (triethylene glycol), etc.

[0058] The mixed gas discharged from the above moisture remover (200) may contain carbon dioxide and nitrogen after moisture has been removed, and may also contain the remainder of moisture, oxygen, hydrogen, etc.

[0059] In one embodiment of the present invention, the carbon dioxide separator (300) may be configured to obtain carbon dioxide from the mixed gas obtained from the moisture remover (200).

[0060] The carbon dioxide separator (300) may be a deep cryogenic separator. The carbon dioxide separator (300) may be at a temperature of about 56.9°C or lower, which is the melting point of carbon dioxide. The carbon dioxide separator (300) may be rapidly cooled to a temperature range below the above-described temperature range to obtain liquid carbon dioxide simultaneously with the separation of carbon dioxide.

[0061] According to one embodiment of the present invention, the molar concentration of each of oxygen, hydrogen, and carbon monoxide contained in the exhaust gas discharged may be 1 mol% or less, and specifically 0.1 mol% or less.

[0062]

[0063] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0064] (Example)

[0065]

[0066] 1. Performance test results according to oxidation catalyst

[0067] An oxidation catalyst according to Table 2 below was coated on the metal mesh surface inside a cylindrical pipe and installed in a combustor at 150 CPSI.

[0068] Oxidation Catalyst Example 1 Pt / Al2O3 Example 2 Co / Al2O3 Example 3 CO3O4 Comparative Example 1 LaCoO3 Comparative Example 2 Co_STO(SrTiCoO), Exsolution Method Application Comparative Example 3 Co_STO(SrTiCoO) Comparative Example 4 Catalyst X

[0069] Subsequently, the conversion rates of carbon monoxide and hydrogen were measured according to temperature and are shown in FIGS. 3 and FIGS. 4, respectively. Referring to FIGS. 3 and FIGS. 4, it can be confirmed that the oxidation catalysts of Examples 1 to 3 have a conversion rate of 99.9% or higher for carbon monoxide and hydrogen at temperatures of approximately 300°C or lower.

[0070] Meanwhile, it can be confirmed that the catalysts of Comparative Examples 1 to 4 have inferior conversion rates of carbon monoxide and hydrogen even at temperatures exceeding 300°C.

[0071]

[0072] 2. Temperature change according to the amount of oxidation catalyst added

[0073] Pt / Al2O3 was coated onto the metal mesh surface inside a cylindrical pipe as an oxidation catalyst and installed in a combustion chamber at 150 CPSI.

[0074] Afterwards, a certain amount of FTG byproduct gas was introduced, and the temperature change of the combustion chamber was measured while increasing the amount of oxidation catalyst introduced from 0 L / min to 9 L / min in a combustion chamber at 500℃, and this is shown in Fig. 5.

[0075] Referring to Fig. 5, it can be seen that as the amount of oxidation catalyst (oxidizer) added increases, the degree of temperature rise of the combustion chamber increases.

[0076] (Explanation of symbols)

[0077] 100: Combustion device

[0078] 200: Moisture remover

[0079] 300: Carbon dioxide separator

Claims

1. A combustor that produces carbon dioxide and water from carbon monoxide and hydrogen contained in a mixed gas; A moisture remover for removing moisture contained in the mixed gas obtained from the above combustion device; and A carbon dioxide capture system comprising a carbon dioxide separator that obtains carbon dioxide from a mixed gas obtained from the above-mentioned moisture remover.

2. In Paragraph 1, The above combustion device is a carbon dioxide capture system comprising an oxidation catalyst.

3. In Paragraph 2, The above oxidation catalyst is a carbon dioxide capture system comprising Pt / Al2O3.

4. In Paragraph 3, A carbon dioxide capture system comprising at least one selected from the group consisting of Co3O4 and Co / Al2O3, wherein the above oxidation catalyst further comprises 5. In Paragraph 1, A carbon dioxide capture system in which the heating temperature of the combustion device is 100 to 300°C.

6. In Paragraph 1, The above-mentioned combustion device further comprises a heat exchanger for recovering the arrangement of carbon monoxide oxidation reactions, a carbon dioxide capture system.

7. In Paragraph 1, The above mixed gas is a carbon dioxide capture system, which is a gas derived from byproduct gas.

8. In Paragraph 7, A carbon dioxide capture system in which the above-mentioned byproduct gas is at least one selected from the group consisting of BFG (Blast Furnace Gas), COG (Coke Oven Gas), LDG (Linz-Donawitz Gas), FOG (Fuel Oil Gas), and FTG (Flare Tower Gas).

9. In Paragraph 1, The above moisture remover comprises at least one selected from the group consisting of a moisture adsorbent and a moisture absorbent, a carbon dioxide capture system.

10. In Paragraph 1, The above carbon dioxide separator is a carbon dioxide capture system including a cryogenic separator.

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