According to one embodiment, there is provided a carbon dioxide fixation system includes an electrolytic cell and a settling tank. An electrolytic cell electrolyzes seawater to generate sodium hydroxide (NaOH). A settling tank mixes the sodium hydroxide generated in the electrolytic cell, concentrated seawater, and carbon dioxide (CO.sub.2) to precipitate magnesium carbonate in which the carbon dioxide is fixed to magnesium (Mg) contained in the concentrated seawater.

According to one embodiment, there is provided a carbon dioxide fixation system includes an electrolytic cell and a settling tank. An electrolytic cell electrolyzes seawater to generate sodium hydroxide (NaOH). A settling tank mixes the sodium hydroxide generated in the electrolytic cell, concentrated seawater, and carbon dioxide (CO.sub.2) to precipitate magnesium carbonate in which the carbon dioxide is fixed to magnesium (Mg) contained in the concentrated seawater.

A method for LiOHH.sub.2O production from lithium-bearing multicomponent hydromineral raw materials includes filtering lithium-bearing brine contaminated with suspended particles with regeneration of filters and processing of used regenerate, and obtaining pregnant lithium-bearing brine, isolation of lithium chloride from the brine in the form of a primary concentrate in sorption-desorption modules, and nanofiltration of the primary lithium concentrate from magnesium, calcium and sulfate ions. By means of reverse osmosis, electrodialysis concentration and ion-exchange purification from impurities followed by thermal concentration, the primary lithium concentrate is converted into a pregnant lithium chloride concentrate which is converted into a LiOH solution by membrane electrolysis. The LiOH solution is boiled down, resulting in LiOH.H.sub.2O crystallization.

A method for LiOHH.sub.2O production from lithium-bearing multicomponent hydromineral raw materials includes filtering lithium-bearing brine contaminated with suspended particles with regeneration of filters and processing of used regenerate, and obtaining pregnant lithium-bearing brine, isolation of lithium chloride from the brine in the form of a primary concentrate in sorption-desorption modules, and nanofiltration of the primary lithium concentrate from magnesium, calcium and sulfate ions. By means of reverse osmosis, electrodialysis concentration and ion-exchange purification from impurities followed by thermal concentration, the primary lithium concentrate is converted into a pregnant lithium chloride concentrate which is converted into a LiOH solution by membrane electrolysis. The LiOH solution is boiled down, resulting in LiOH.H.sub.2O crystallization.

One aspect of the present invention provides a sodium hydroxide production device, which includes: a first tank configured to store a sodium salt including two or more sodium ions in a molecule; a first electrolysis unit including a first anode chamber and a first cathode chamber which are partitioned by a first separator; and a water supply unit configured to supply water to the first tank and the first cathode chamber, wherein the first tank, a pipe configured to supply an aqueous sodium salt solution produced in the first tank to the first anode chamber, the first anode chamber, and a pipe configured to supply a material produced in the first anode chamber to the first tank constitute a closed loop, and a sodium hypochlorite production device including the same.

One aspect of the present invention provides a sodium hydroxide production device, which includes: a first tank configured to store a sodium salt including two or more sodium ions in a molecule; a first electrolysis unit including a first anode chamber and a first cathode chamber which are partitioned by a first separator; and a water supply unit configured to supply water to the first tank and the first cathode chamber, wherein the first tank, a pipe configured to supply an aqueous sodium salt solution produced in the first tank to the first anode chamber, the first anode chamber, and a pipe configured to supply a material produced in the first anode chamber to the first tank constitute a closed loop, and a sodium hypochlorite production device including the same.

A coated electrode assembly (CEA) comprising: i) a gas diffusion layer (GDE); and ii) a coating. The GDE comprises a gas diffusion layer (GDL) and a catalyst layer. The catalyst layer is disposed between the coating and the GDL. The catalyst layer comprises a hydrophobic polymer and/or an ionomeric polymer and the coating comprises a hydrophobic polymer and/or an ionomeric polymer. A method for making a CEA is provided. The CEA may have improved performance and stability compared to a membrane electrode assembly (MEA).

[Problem] To provide a stacked structure including electrodes that can effectively prevent misalignment between units. [Solution] A stacked structure 2 including electrodes 232, 332, 412, 233, 333, 422, wherein multiple units 23, 33, 24, 41, 42 including flat units are stacked and fastened by fasteners 25, the respective units 23, 33, 24, 41, 42 comprising frame-shaped fastening portions 237a, 237b, 337a, 337b, 247a, 247b, 417a, 417b, 427a, 427b on outer peripheral portions on both surfaces thereof, being stacked by the surfaces of the respective fastening portions 237a, 237b, 337a, 337b, 247a, 247b, 417a, 417b, 427a, 427b being pressed against each other, and being formed so that the width of fastening portions 247a, 247b, 337a, 337b, 427a, 427b on one unit is different from the width of fastening portions 237a, 237b, 417a, 417b on another unit.

Techniques according to the present disclosure include capturing carbon dioxide from a dilute gas source with a CO.sub.2 capture solution to form a carbonate-rich capture solution; separating at least a portion of carbonate from the carbonate-rich capture solution; forming an electrodialysis (ED) feed solution; flowing a water stream and the ED feed solution to a bipolar membrane electrodialysis (BPMED) unit; applying an electric potential to the BPMED unit to form at least two ED product streams including a first ED product stream including a hydroxide; and flowing the first ED product stream to use in the capturing the carbon dioxide from the dilute gas source with the CO.sub.2 capture solution.

Techniques according to the present disclosure include capturing carbon dioxide from a dilute gas source with a CO.sub.2 capture solution to form a carbonate-rich capture solution; separating at least a portion of carbonate from the carbonate-rich capture solution; forming an electrodialysis (ED) feed solution; flowing a water stream and the ED feed solution to a bipolar membrane electrodialysis (BPMED) unit; applying an electric potential to the BPMED unit to form at least two ED product streams including a first ED product stream including a hydroxide; and flowing the first ED product stream to use in the capturing the carbon dioxide from the dilute gas source with the CO.sub.2 capture solution.