An electrochemical reaction device includes: an electrode layer including a cathode, an ion exchange membrane, and an anode that are stacked in this order; a first flow path structure including an anode-specific flow path as a passage for an electrolytic solution defined by a surface on one side and a cathode-specific flow path as a passage for an electrolytic solution containing dissolved carbon dioxide defined by a surface on the other side; and a second flow path structure including an anode-specific flow path as a passage for an electrolytic solution defined by a surface on one side and a cathode-specific flow path as a passage for an electrolytic solution containing dissolved carbon dioxide defined by a surface on the other side. The first flow path structure, the electrode layer, the second flow path structure, and the electrode layer are stacked in this order repeatedly to form an electrolytic cell stacking structure.

A water electrolysis system includes a control device. The control device outputs a first current command value, which is a constant current command value, to one from among a first power source device and a second power source device. The control device generates a second current command value, which is an undefined current command value, based on an amount of the hydrogen gas inside a gas-liquid separator, and outputs the second current command value to another one from among the first power source device and the second power source device.

A water electrolysis system includes a control device. The control device outputs a first current command value, which is a constant current command value, to one from among a first power source device and a second power source device. The control device generates a second current command value, which is an undefined current command value, based on an amount of the hydrogen gas inside a gas-liquid separator, and outputs the second current command value to another one from among the first power source device and the second power source device.

Disclosed are an electrolysis cell system and a method for preparing hydrogen and oxygen. The electrolysis cell system includes: an anode chamber with an inlet and an outlet; a cathode chamber with an inlet and an outlet; a composite membrane electrode set between the anode chamber and the cathode chamber, which includes a cation exchange membrane in alkali-ion form with an anode catalyst coated on one side thereof and a cathode catalyst coated on the other side thereof; a continuous or intermittent flow of an aqueous alkaline electrolyte through the anode chamber and the cathode chamber. The electrolysis cell system of the present disclosure features low material cost, long membrane service life, high operating temperature, low operating requirements and high safety; when it is used to prepare hydrogen and oxygen, gas with relatively high purity can be obtained.

Disclosed are an electrolysis cell system and a method for preparing hydrogen and oxygen. The electrolysis cell system includes: an anode chamber with an inlet and an outlet; a cathode chamber with an inlet and an outlet; a composite membrane electrode set between the anode chamber and the cathode chamber, which includes a cation exchange membrane in alkali-ion form with an anode catalyst coated on one side thereof and a cathode catalyst coated on the other side thereof; a continuous or intermittent flow of an aqueous alkaline electrolyte through the anode chamber and the cathode chamber. The electrolysis cell system of the present disclosure features low material cost, long membrane service life, high operating temperature, low operating requirements and high safety; when it is used to prepare hydrogen and oxygen, gas with relatively high purity can be obtained.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

A carbon dioxide treatment apparatus, a carbon dioxide treatment method, and a method for producing a carbon compound that have high energy efficiency in recovery and reduction of carbon dioxide and are highly effective in reducing loss of carbon dioxide. The carbon dioxide treatment apparatus (100) includes a recovery device (1) configured to recover carbon dioxide, an electrochemical reaction device (2) configured to electrochemically reduce carbon dioxide, and a pH adjuster (52), wherein pH of a cathode side electrolytic solution is higher than that of an anode side electrolytic solution, carbon dioxide gas is supplied from a concentration part 11 to a gas flow path on a side of a cathode (21) opposite to an anode (22), and the carbon dioxide gas is reduced at the cathode (21).

A carbon dioxide treatment apparatus, a carbon dioxide treatment method, and a method for producing a carbon compound that have high energy efficiency in recovery and reduction of carbon dioxide and are highly effective in reducing loss of carbon dioxide. The carbon dioxide treatment apparatus (100) includes a recovery device (1) configured to recover carbon dioxide, an electrochemical reaction device (2) configured to electrochemically reduce carbon dioxide, and a pH adjuster (52), wherein pH of a cathode side electrolytic solution is higher than that of an anode side electrolytic solution, carbon dioxide gas is supplied from a concentration part 11 to a gas flow path on a side of a cathode (21) opposite to an anode (22), and the carbon dioxide gas is reduced at the cathode (21).

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.