A microwave-plasma system for generating fixed-nitrogen products comprises a microwave generator operably coupled with a gas chamber where the microwave generator provides microwave power to the gas chamber. The system further includes a source of gas, which may be for example oxygen, nitrogen and/or air, operably coupled with the plasma chamber. The microwave power produces a plasma of the gas within the chamber. The system further includes an absorber unit fluidically connected to the gas chamber to capture product from the plasma in the gas chamber. The captured product may include fixed nitrogen gaseous products.

A microwave-plasma system for generating fixed-nitrogen products comprises a microwave generator operably coupled with a gas chamber where the microwave generator provides microwave power to the gas chamber. The system further includes a source of gas, which may be for example oxygen, nitrogen and/or air, operably coupled with the plasma chamber. The microwave power produces a plasma of the gas within the chamber. The system further includes an absorber unit fluidically connected to the gas chamber to capture product from the plasma in the gas chamber. The captured product may include fixed nitrogen gaseous products.

The present invention describes an integrated process for carbon dioxide capture, sequestration and utilisation, which comprises: a) providing an aqueous slurry comprising an aqueous solution and a particulate solid comprising an activated magnesium silicate mineral; b) in a dissolution stage, contacting a CO.sub.2-containing gas stream with the aqueous slurry to dissolve magnesium from the mineral to provide a magnesium ion enriched aqueous solution and a magnesium depleted solid residue; c) recovering at least a portion of the magnesium depleted solid residue; d) in a separate acid treatment stage, reacting the recovered portion of the magnesium depleted solid residue with a solution comprising a mineral acid or acid salt to further dissolve magnesium and other metals and to provide an acid-treated solid residue; e) recovering the acid-treated solid residue; and f) in a separate precipitation stage, precipitating magnesium carbonate from the magnesium ion enriched aqueous solution.

The present invention describes an integrated process for carbon dioxide capture, sequestration and utilisation, which comprises: a) providing an aqueous slurry comprising an aqueous solution and a particulate solid comprising an activated magnesium silicate mineral; b) in a dissolution stage, contacting a CO.sub.2-containing gas stream with the aqueous slurry to dissolve magnesium from the mineral to provide a magnesium ion enriched aqueous solution and a magnesium depleted solid residue; c) recovering at least a portion of the magnesium depleted solid residue; d) in a separate acid treatment stage, reacting the recovered portion of the magnesium depleted solid residue with a solution comprising a mineral acid or acid salt to further dissolve magnesium and other metals and to provide an acid-treated solid residue; e) recovering the acid-treated solid residue; and f) in a separate precipitation stage, precipitating magnesium carbonate from the magnesium ion enriched aqueous solution.

A method of purifying air polluted by smoke and fumes, such as from wildfires and other hazard, may deploy a series of fluid filled vessels that act as filters to trap and/or neutralize components that would foul an aqueous suspension of gold nanoparticles that is effective in converting toxic carbon monoxide to carbon dioxide. Non-toxic fluids may be used. As the gold nanoparticles are effective in a basic solution, the solution may contain a visible pH indicator or an apparatus that deploys the method may continuously monitor the pH thereof.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

Embodiments of the present disclosure are directed to systems and methods of removing carbon dioxide from a gaseous stream using magnesium hydroxide and then regenerating the magnesium hydroxide. In some embodiments, the systems and methods can further comprise using the waste heat from one or more gas streams to provide some or all of the heat needed to drive the reactions. In some embodiments, magnesium chloride is primarily in the form of magnesium chloride dihydrate and is fed to a decomposition reactor to generate magnesium hydroxychloride, which is in turn fed to a second decomposition reactor to generate magnesium hydroxide.

A method for producing and using an alkaline aqueous ferric iron carbonate solution is disclosed. The method broadly comprises reacting at least one ferric iron salt reagent with at least one alkali metal carbonate salt reagent and forming an alkaline aqueous ferric iron carbonate solution comprising an aqueous-soluble, ferric iron carbonate complex. The reacting generally includes reacting a solid with an aqueous solution. The reacting may include reacting a solid comprising one or both of the ferric iron salt reagent and alkali metal carbonate salt reagent with an aqueous solution. A method for removing reduced sulfur compounds from a reduced sulfur-containing fluid is also disclosed.

A method for producing and using an alkaline aqueous ferric iron carbonate solution is disclosed. The method broadly comprises reacting at least one ferric iron salt reagent with at least one alkali metal carbonate salt reagent and forming an alkaline aqueous ferric iron carbonate solution comprising an aqueous-soluble, ferric iron carbonate complex. The reacting generally includes reacting a solid with an aqueous solution. The reacting may include reacting a solid comprising one or both of the ferric iron salt reagent and alkali metal carbonate salt reagent with an aqueous solution. A method for removing reduced sulfur compounds from a reduced sulfur-containing fluid is also disclosed.

The device for producing and treating a gas stream (F) includes an exchange enclosure (2) having at least a first discharge opening (2b) for a gas stream, means (3; 4) for supplying the enclosure with a liquid (L), means (3; 5) for discharging the liquid (L) contained in the exchange enclosure (2) and aeraulic means (6), which make it possible, during operation, to create, by means of suction or blowing, an incoming gas stream (F) coming from outside the exchange enclosure (2), so that said incoming gas stream (F) is introduced into the volume of liquid (V) contained in the exchange enclosure (2), and an outgoing gas stream (F′), treated by direct contact with said volume of liquid, rises inside the exchange enclosure and is discharged out of the exchange enclosure (2) through the discharge opening (2b).