KR-102963700-B1 - Carbon Dioxide Conversion Hybrid Power System based on Magnesium-Air Secondary Battery and Seawater Desalination System Thereby

KR102963700B1KR 102963700 B1KR102963700 B1KR 102963700B1KR-102963700-B1

Abstract

The present invention relates to a magnesium-air secondary battery-based carbon dioxide conversion hybrid power system capable of generating power through an oxygen reduction reaction (ORR) during the discharge process of a magnesium-air secondary battery and simultaneously generating carbonates through a carbonation reaction of carbon dioxide.

Inventors

리 오이 룬
김성희

Assignees

부산대학교 산학협력단

Dates

Publication Date: 20260512
Application Date: 20240716
Priority Date: 20230718

Claims (10)

A reaction vessel containing an electrolyte solution; A magnesium electrode located within the above reaction vessel; An air electrode that induces an oxygen reduction reaction (ORR) located within the above-mentioned reaction vessel; A connecting portion connecting the magnesium electrode and the air electrode; and It includes a gas injection device for injecting a gas containing carbon dioxide into the above electrolyte solution, and Characterized by the generation of bicarbonate ( HCO₃- ) or carbonate ( CO₃²⁻ )-based substances by a carbonation reaction within the above electrolyte solution. Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 1, The above electrolyte solution includes concentrated seawater, Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 1, The above air electrode includes a non-precious metal catalyst, Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 3, The above non-precious metal catalyst comprises an iron-bonded nitrogen-doped carbon (Fe-NC) catalyst, Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 1, Characterized by maintaining the pH of the electrolyte solution at 7.0 to 9.0 through the oxygen reduction reaction (ORR) and the carbonation reaction. Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 5, The above gas injection device further includes a device for controlling the amount of gas containing carbon dioxide to maintain the pH of the electrolyte solution. Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 1, A device additionally comprising for separating the above-mentioned generated bicarbonate ( HCO₃- ) or carbonate ( CO₃²⁻ )-based substances, Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 1, The gas injected into the above gas injection device is an exhaust gas containing carbon dioxide and oxygen, and Characterized by being able to additionally supply oxygen to the air electrode by the exhaust gas. Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
In paragraph 1, The above magnesium-air secondary battery-based carbon dioxide conversion hybrid power system is a power generation facility installed near the coast, Magnesium-air secondary battery-based carbon dioxide conversion hybrid power system.
Desalination tank containing high-concentration seawater electrolytes; An oxidation electrode located within the above-mentioned desalination tank; A reduction electrode located within the above-mentioned desalination tank; and A means for applying power produced in a magnesium-air secondary battery-based carbon dioxide conversion hybrid power system according to any one of claims 1 to 9 to the oxidation electrode and the reduction electrode, Seawater desalination system.

Description

Carbon Dioxide Conversion Hybrid Power System based on Magnesium-Air Secondary Battery and Seawater Desalination System Thereby The present invention relates to an eco-friendly battery technology for power generation and carbon dioxide reduction, specifically a technology that generates power and directly reduces carbon dioxide by utilizing a magnesium-carbon dioxide battery based on a magnesium-air electrode. Carbon Capture and Utilization (CCU) technology is capable of converting carbon dioxide into various chemical raw materials, energy sources, and construction materials using chemical or electrochemical methods. The carbon dioxide resource recovery technology utilizing concentrated seawater employs a technique that mineralizes HCO₃⁻ spontaneously dissolved in seawater by leveraging the calcium ions ( Ca²⁺ ) and magnesium ions ( Mg²⁺ ) abundant in the concentrated seawater. A process for converting calcium and magnesium ions contained in concentrated seawater from desalination facilities into economically viable carbonate minerals had already been developed. Korea Electric Power Corporation (KEPCO) has developed a technology to produce sodium bicarbonate ( NaHCO₃ ) by reacting carbon dioxide from thermal power plant exhaust gases with sodium hydroxide produced through brine electrolysis, and plans to install a demonstration plant with Lotte Chemical to reduce carbon dioxide emissions by 20,000 tons annually. LG Chem plans to construct a pilot plant to produce 1,000 tons of plastic using carbon dioxide and methane, a byproduct gas, which is expected to result in a 50% reduction in carbon dioxide emissions. In 2019, the Korea Institute of Geoscience and Mineral Resources developed a technology to reduce greenhouse gases by dissolving carbon dioxide in seawater and carbonating metal ions. In 2021, UNIST also developed a technology to carbonate carbon dioxide in seawater using an electrochemical reaction. Iridium oxide ( IrO2 ) was used as the electrode material, and this iridium oxide is a precious metal. However, while it was possible to generate an electrochemical reaction using a precious metal material like iridium oxide when using a basic electrolyte containing sodium chloride (NaCl), it was confirmed that the performance deteriorates significantly when using pure seawater. As mentioned above, research on technology for reducing carbon dioxide by directly injecting it into concentrated seawater has been conducted several times in Korea. However, these prior studies required a pretreatment process to adjust the pH of the seawater, which presented a problem in that constructing facilities for large-scale CO2 treatment would result in significant cost expenditures due to pretreatment expenses. Furthermore, while the use of precious metal catalysts is generally essential for batteries utilizing electrochemical reactions, precious metal materials degrade easily due to the strong adsorption of chloride ions in seawater. Moreover, they fail to exhibit sufficient activity, particularly in seawater containing high salt concentrations such as concentrated seawater, making them practically difficult to use. The development of Mg- CO₂HER cells, a technology for indirectly utilizing carbon dioxide, has been carried out abroad. Since the conversion of carbon dioxide in Mg- CO₂HER cells takes place in the electrolyte, carbon dioxide can be converted into carbonates, and the produced hydrogen can also be used as fuel. However, there is a problem in that the anode of the Mg-HER cell system requires an expensive platinum (Pt) catalyst. In addition, there is a problem in that performance is significantly degraded if impurities such as NOx and SOx are present. Therefore, it is difficult to ignore the influence of the purity of the input carbon dioxide on the Mg-HER system, and thus the carbon dioxide process cannot be excluded. Accordingly, the present invention proposes a technology for converting carbon dioxide based on a magnesium-air secondary battery. In order to overcome existing technical limitations, the present invention introduces a non-precious metal catalyst to reduce costs and prevent degradation caused by the adsorption of chloride ions in seawater. At the same time, a system capable of effectively reducing and utilizing carbon dioxide has been developed through a process of dissolving carbon dioxide in concentrated seawater and converting it into magnesium and calcium carbonates. FIG. 1 is a diagram illustrating the concept of a continuous carbon dioxide conversion process utilizing magnesium-carbon dioxide concentrated seawater battery technology according to one embodiment of the present invention. Figure 2a shows graphs of cell voltage and pH changes of a magnesium-air secondary battery at a specific current density or open circuit voltage. Figure 2b is a graph showing the solubility of various metal hydroxides according to pH. Figure 3a is a schematic diagram showing the carbonation reaction of carbon