KR-20260064342-A - Device and method for selective capture and conversion of nitrogen oxide using Fe(II)-salen

Abstract

The present disclosure discloses a nitrogen oxide capture agent and an apparatus and method for the selective capture and conversion of nitrogen oxides using the same. The nitrogen oxide capture agent comprises a ligand in the form of salen centered on a transition metal, wherein the transition metal comprises iron (Fe). The nitrogen oxide capture agent has the effect of providing excellent nitrogen oxide capture performance without being deactivated by oxygen present in the flue gas.

Inventors

• 이현주
• 이동기
• 김지윤
• 엄희성
• 정석현

Assignees

• 한국과학기술연구원

Dates

Publication Date

20260507

Application Date

20241031

Claims (15)

1. Centered on a transition metal and containing a salen-type ligand, A nitrogen oxide capture agent in which the above transition metal includes iron (Fe).
2. In Article 1, A nitrogen oxide capture agent comprising one or more selected from the group consisting of compounds of the following chemical formulas 1 to 5, wherein the above-mentioned salen-type ligand comprises the above-mentioned one or more. [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 4] [Chemical Formula 5]
3. In Article 1, A nitrogen oxide capture agent in which the above transition metal and the salen-type ligand are mixed in a molar ratio of 1:0.2 to 2.
4. In Article 1, The above nitrogen oxide collector is a nitrogen oxide collector that uses water as a solvent.
5. In Paragraph 4, A nitrogen oxide capture agent in which the aqueous solution in which the above nitrogen oxide capture agent is dissolved has a concentration of 1 to 20 mM.
6. A selective capture and conversion device for nitrogen oxides using a nitrogen oxide capture agent according to any one of claims 1 to 5, and said device, A supply section where gas is supplied; A collection unit that collects nitrogen oxides in the gas supplied from the supply unit using the above nitrogen oxide collection agent; and A selective capture and conversion device for nitrogen oxides comprising an electrochemical cell portion for electrochemically reducing the captured nitrogen oxides.
7. In Paragraph 6, The above electrochemical cell part is a selective capture and conversion device for nitrogen oxides that reduces captured nitrogen oxides to produce ammonia.
8. In Paragraph 6, The above electrochemical cell part is a selective capture and conversion device for nitrogen oxides, wherein the electrochemical cell part contains nickel and molybdenum and uses an electrode having a microform shape as a reduction electrode.
9. In Paragraph 8, The above electrochemical cell part is a selective capture and conversion device for nitrogen oxides, wherein the electrode containing platinum (Pt) is used as the oxidation electrode.
10. In Paragraph 6, A selective capture and conversion device for nitrogen oxides, wherein the electrochemical cell section performs a reduction reaction by applying a voltage of -0.2 to -0.4 V (vs. RHE).
11. A method for the selective capture and conversion of nitrogen oxides using a nitrogen oxide capture agent according to any one of claims 1 to 5, wherein the method comprises: Step of supplying gas; A step of capturing nitrogen oxides in the supplied gas using the above nitrogen oxide capture agent; and A method for the selective capture and conversion of nitrogen oxides, comprising the step of electrochemically reducing the captured nitrogen oxides.
12. In Paragraph 11, A method for the selective capture and conversion of nitrogen oxides, wherein the reduction step involves reducing the captured nitrogen oxides to produce ammonia.
13. In Paragraph 11, A method for the selective capture and conversion of nitrogen oxides, wherein the above reduction step uses an electrode containing nickel and molybdenum and having a microform shape as a reduction electrode.
14. In Paragraph 13, A method for the selective capture and conversion of nitrogen oxides, wherein the reduction step above uses an electrode containing platinum (Pt) as an oxidation electrode.
15. In Paragraph 11, A method for the selective capture and conversion of nitrogen oxides, wherein the above reduction step involves carrying out a reduction reaction by applying a voltage of -0.2 to -0.4 V (vs. RHE).

Description

Device and method for selective capture and conversion of nitrogen oxide using Fe(II)-salen The present disclosure discloses a nitrogen oxide capture agent and an apparatus and method for the selective capture and conversion of nitrogen oxides using the same. Nitrogen oxides (NOx), a major cause of environmental problems among gaseous air pollutants, refer to NO2 and NO, and are generated during the combustion of fossil fuels in power plants, automobiles, etc. Approximately 90% of nitrogen oxides produced by combustion are emitted in the form of NO and about 10% as NO2 , and NO is converted into NO2 in the atmosphere. Nitrogen oxides in the flue gas of thermal power plants are a cause of acid rain and fine dust; as regulations on nitrogen oxide emissions are tightened, the need to reduce emission concentrations from major emission facilities is gradually increasing. Since nitrogen oxides are primarily generated by the reaction of nitrogen and oxygen in the air under high temperatures, various methods are being used to reduce their generation, including low-oxygen combustion, low-temperature combustion, combustion section cooling, exhaust gas recirculation, two-stage combustion, and structural improvements to burners and combustion chambers. Furthermore, Selective Catalytic Reduction (SCR) is currently the most widely used treatment technology to remove already generated nitrogen oxides. However, this method faces the problem of high costs due to the continuous consumption of chemicals (e.g., ammonia, urea) and the deactivation of SCR catalysts. Figure 1 shows a schematic diagram of a nitrogen oxide capture and reduction reaction according to one embodiment. Figure 2 shows the NO capture results using Fe(II)-(Salen- SO₃ ) in one embodiment. Figure 3 shows the SEM-EDS analysis results of a NiMo MF electrode manufactured according to one embodiment. FIG. 4 shows an electrochemical apparatus used in one embodiment. Figure 5 shows a comparison of the NO reduction reaction according to the electrode type in one embodiment, indicating the NH3 production rate and power efficiency (FE). Figure 6 compares the NO reduction reaction according to the nitrogen oxide capture agent and voltage in one embodiment, showing the NH3 production rate and power efficiency (FE). Figure 7 shows a comparison of the NO reduction reaction according to electrode and pH conditions in one embodiment, and indicates the power efficiency (FE). The present disclosure will be described in detail below. In one aspect, the present disclosure provides a nitrogen oxide capture agent comprising a transition metal as the center and a salen-type ligand, wherein the transition metal comprises iron (Fe). In an exemplary embodiment, the nitrogen oxide capture agent may capture nitrogen oxides in the supplied gas. In an exemplary embodiment, the gas may be air or flue gas. In an exemplary embodiment, the gas may include oxygen and nitric oxide. In an exemplary embodiment, the nitrogen oxide may be nitric oxide. Flue gas contains a large amount of oxygen, and Fe(II) is rapidly oxidized to Fe(III) by oxygen. Since Fe(III) lacks NO adsorption capacity, the Fe(II)-EDTA system consequently loses its nitrogen oxide capture performance. The present disclosure utilizes a compound centered on iron (Fe) and containing a salen-type ligand as a nitrogen oxide capture agent, thereby providing excellent stability against large amounts of oxygen in flue gas compared to conventional Fe(II)-EDTA systems. In an exemplary embodiment, the salen-type ligand may comprise one or more selected from the group consisting of compounds of the following chemical formulas 1 to 5. [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] [Chemical Formula 4] [Chemical Formula 5] In an exemplary embodiment, the transition metal and the salen-type ligand may be mixed in a molar ratio of 1:0.2 to 2, 1:0.5 to 1.5, 1:0.5 to 1.0, 1:1.0 to 1.5, 1:0.8 to 1.2, or 1:0.9 to 1.1. In an exemplary embodiment, the nitrogen oxide capture agent may be obtained by mixing a transition metal precursor with a salen-type ligand. In an exemplary embodiment, the nitrogen oxide capture agent may be obtained by dissolving a transition metal precursor and a salen-type ligand in a solvent. In an exemplary embodiment, the nitrogen oxide collector may use water as a solvent. In one exemplary embodiment, the aqueous solution in which the nitrogen oxide capture agent is dissolved may have a concentration of 1 to 20 mM. In another exemplary embodiment, the aqueous solution in which the nitrogen oxide capture agent is dissolved may have a concentration of 1 mM or more, 3 mM or more, 5 mM or more, 7 mM or more, or 10 mM or more, and may have a concentration of 20 mM or less, 17 mM or less, 15 mM or less, 13 mM or less, or 10 mM or less. In another aspect, the present disclosure provides a selective capture and conversion device for nitrogen oxides using the nitrogen oxide capture agent, wherein the device comprise