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.

The present invention relates to a manufacturing apparatus and method for customizing a H.sub.2/CO synthetic gas in a desired ratio by producing a synthetic gas in which H.sub.2 and CO are mixed through hydrolysis of both carbon dioxide and a nitrogen compound with low power. In a low-power electrochemical apparatus for producing a synthetic gas according to the present invention, by performing the reduction of the carbon dioxide at the cathode and the oxidation of the nitrogen compound at the anode at the same time, carbon dioxide conversion efficiency may be improved 30% or more compared to the conventional carbon dioxide conversion system, and a synthetic gas with a desired H.sub.2/CO ratio may be produced by controlling the H.sub.2/CO ratio of the produced synthetic gas, and by reducing a driving voltage, the corrosion problem of electrode materials may be inhibited and the durability of electrodes may be increased.

The present invention relates to a manufacturing apparatus and method for customizing a H.sub.2/CO synthetic gas in a desired ratio by producing a synthetic gas in which H.sub.2 and CO are mixed through hydrolysis of both carbon dioxide and a nitrogen compound with low power. In a low-power electrochemical apparatus for producing a synthetic gas according to the present invention, by performing the reduction of the carbon dioxide at the cathode and the oxidation of the nitrogen compound at the anode at the same time, carbon dioxide conversion efficiency may be improved 30% or more compared to the conventional carbon dioxide conversion system, and a synthetic gas with a desired H.sub.2/CO ratio may be produced by controlling the H.sub.2/CO ratio of the produced synthetic gas, and by reducing a driving voltage, the corrosion problem of electrode materials may be inhibited and the durability of electrodes may be increased.

An abrupt interface electroreduction catalyst includes a porous gas diffusion layer and a catalyst layer providing a sharp reaction interface. The electroreduction catalyst can be used for converting CO.sub.2 into a target product such as ethylene. The porous gas diffusion layer can be hydrophobic and configured for contacting gas-phase CO.sub.2 while the catalyst layer is disposed on and covers a reaction interface side of the porous gas diffusion layer. The catalyst layer has another side contacting an electrolyte and can be hydrophilic, composed a metal such as Cu and is sufficiently thin to prevent diffusion limitations of the reactant in the electrolyte and enhance selectivity for the target product. The electroreduction catalyst can be made by vapor deposition methods and can be used for electrochemical production of ethylene in reaction system.

A composite for a porous transport layer may include a particulate substrate including at least one selected from a group consisting of an oxide of a first metal and a second metal, and nanoparticles of a third metal formed on a surface of the particulate substrate, a sintered body thereof, and a method for preparing the same.

A composite for a porous transport layer may include a particulate substrate including at least one selected from a group consisting of an oxide of a first metal and a second metal, and nanoparticles of a third metal formed on a surface of the particulate substrate, a sintered body thereof, and a method for preparing the same.

An electrochemical system, an electrochemical stack and a method for carbon dioxide capture and carbon dioxide recovery. The system has a CO.sub.2 capture device where a metal hydroxide base solution reacts with CO.sub.2 to produce carbonates and bicarbonates. The electrochemical stack has one or more electrochemical cells, each with a gas diffusion anode having a hydrogen supply, a cathode spaced from the anode to define an electrolysis region between them for a salt solution, a cation exchange membrane in the electrolysis region next to the cathode and a metal hydroxide region separated from the electrolysis region by the cathode.

A voltage potential between the anode and cathode produces an acid solution in the electrolysis region, conditions the metal hydroxide base solution in the metal hydroxide region and evolves hydrogen at the cathode. A CO.sub.2 evolution device uses the acid and the carbonates and/or bicarbonates to recover CO.sub.2 and to recover the salt solution for reuse in the electrochemical stack.

An electrochemical system, an electrochemical stack and a method for carbon dioxide capture and carbon dioxide recovery. The system has a CO.sub.2 capture device where a metal hydroxide base solution reacts with CO.sub.2 to produce carbonates and bicarbonates. The electrochemical stack has one or more electrochemical cells, each with a gas diffusion anode having a hydrogen supply, a cathode spaced from the anode to define an electrolysis region between them for a salt solution, a cation exchange membrane in the electrolysis region next to the cathode and a metal hydroxide region separated from the electrolysis region by the cathode.

A voltage potential between the anode and cathode produces an acid solution in the electrolysis region, conditions the metal hydroxide base solution in the metal hydroxide region and evolves hydrogen at the cathode. A CO.sub.2 evolution device uses the acid and the carbonates and/or bicarbonates to recover CO.sub.2 and to recover the salt solution for reuse in the electrochemical stack.

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.