There are provided processes comprising submitting an aqueous composition comprising lithium sulphate and/or bisulfate to an electrolysis or an electrodialysis for converting at least a portion of said sulphate into lithium hydroxide. During electrolysis or electrodialysis, the aqueous composition is at least substantially maintained at a pH having a value of about 1 to about 4; and converting said lithium hydroxide into lithium carbonate. Alternatively, lithium sulfate and/or lithium bisulfate can be submitted to a first electromembrane process that comprises a two-compartment membrane process for conversion of lithium sulfate and/or lithium bisulfate to lithium hydroxide, and obtaining a first lithium-reduced aqueous stream and a first lithium hydroxide-enriched aqueous stream; and submitting said first lithium-reduced aqueous stream to a second electromembrane process comprising a three-compartment membrane process to prepare at least a further portion of lithium hydroxide and obtaining a second lithium-reduced aqueous stream and a second lithium-hydroxide enriched aqueous stream.

There are provided processes comprising submitting an aqueous composition comprising lithium sulphate and/or bisulfate to an electrolysis or an electrodialysis for converting at least a portion of said sulphate into lithium hydroxide. During electrolysis or electrodialysis, the aqueous composition is at least substantially maintained at a pH having a value of about 1 to about 4; and converting said lithium hydroxide into lithium carbonate. Alternatively, lithium sulfate and/or lithium bisulfate can be submitted to a first electromembrane process that comprises a two-compartment membrane process for conversion of lithium sulfate and/or lithium bisulfate to lithium hydroxide, and obtaining a first lithium-reduced aqueous stream and a first lithium hydroxide-enriched aqueous stream; and submitting said first lithium-reduced aqueous stream to a second electromembrane process comprising a three-compartment membrane process to prepare at least a further portion of lithium hydroxide and obtaining a second lithium-reduced aqueous stream and a second lithium-hydroxide enriched aqueous stream.

Systems and methods are provided for reclaiming CO.sub.2 from air. The method includes absorbing solar radiation using a special photovoltaic panel, the H-SPV, which is so designed that the heat absorbed by the H-SPV is conducted to the back of the H-SPV to the substrate, and there it is cooled by the airstream behind it. A second supporting panel is included to provide enclosure for the heated air that rises between the two panels by the chimney effect, the heated air between the at least two plates will rise by the chimney effect, sucking in more air to be heated, wherein the air includes CO.sub.2, chemically removing the CO.sub.2 from the heated air, using a coolant liquid, wherein the coolant liquid in a heat exchanger, when in contact with the CO.sub.2 in the heated air, forms a bicarbonate, and releasing air that has had the CO.sub.2 chemically removed.

Systems and methods are provided for reclaiming CO.sub.2 from air. The method includes absorbing solar radiation using a special photovoltaic panel, the H-SPV, which is so designed that the heat absorbed by the H-SPV is conducted to the back of the H-SPV to the substrate, and there it is cooled by the airstream behind it. A second supporting panel is included to provide enclosure for the heated air that rises between the two panels by the chimney effect, the heated air between the at least two plates will rise by the chimney effect, sucking in more air to be heated, wherein the air includes CO.sub.2, chemically removing the CO.sub.2 from the heated air, using a coolant liquid, wherein the coolant liquid in a heat exchanger, when in contact with the CO.sub.2 in the heated air, forms a bicarbonate, and releasing air that has had the CO.sub.2 chemically removed.

A carbonator reactor includes a cylindrical body, a nozzle for supplying a gas stream, inside the carbonator reactor and above the surface of a liquid phase and where the nozzle is located at the top of the reactor body, an inlet, an outlet, means for regulating the temperature and the pressure, a stirring system and at least one baffle regulating the stirring of the liquid phase and the mass transfer of the gas into the liquid surface, at least one impeller having inclined blades that make an angle from 5? to 60? with respect to the vertical axis. The reactor prepares sodium carbonate and has a configuration for the mass transfer of a gas phase in a liquid phase. A method for the preparation of sodium carbonate by means of the carbonator reactor by capturing CO.sub.2 in an NaOH aqueous solution, directly on the free surface of the liquid phase.

A carbonator reactor includes a cylindrical body, a nozzle for supplying a gas stream, inside the carbonator reactor and above the surface of a liquid phase and where the nozzle is located at the top of the reactor body, an inlet, an outlet, means for regulating the temperature and the pressure, a stirring system and at least one baffle regulating the stirring of the liquid phase and the mass transfer of the gas into the liquid surface, at least one impeller having inclined blades that make an angle from 5? to 60? with respect to the vertical axis. The reactor prepares sodium carbonate and has a configuration for the mass transfer of a gas phase in a liquid phase. A method for the preparation of sodium carbonate by means of the carbonator reactor by capturing CO.sub.2 in an NaOH aqueous solution, directly on the free surface of the liquid phase.

A method for recovery of aluminum hydroxide Al(OH).sub.3 from an aluminum enriched water/wastewater treatment sludge is disclosed. The method includes the steps of: adding a hydrated lime slurry to the aluminum enriched water/wastewater treatment sludge to form an alkaline sludge; adding sodium carbonate Na.sub.2CO.sub.3 to the alkaline sludge to form a Na.sub.2CO.sub.3 treated sludge; forming a first supernatant from the Na.sub.2CO.sub.3 treated sludge of step b) containing NaAl(OH).sub.4; introducing CO.sub.2 to the first supernatant to form a precipitate of Al(OH).sub.3 and a second supernatant containing NaHCO.sub.3; and recycling at least a portion of the NaHCO.sub.3 from the second supernatant back to the alkaline sludge of step a).

A method for recovery of aluminum hydroxide Al(OH).sub.3 from an aluminum enriched water/wastewater treatment sludge is disclosed. The method includes the steps of: adding a hydrated lime slurry to the aluminum enriched water/wastewater treatment sludge to form an alkaline sludge; adding sodium carbonate Na.sub.2CO.sub.3 to the alkaline sludge to form a Na.sub.2CO.sub.3 treated sludge; forming a first supernatant from the Na.sub.2CO.sub.3 treated sludge of step b) containing NaAl(OH).sub.4; introducing CO.sub.2 to the first supernatant to form a precipitate of Al(OH).sub.3 and a second supernatant containing NaHCO.sub.3; and recycling at least a portion of the NaHCO.sub.3 from the second supernatant back to the alkaline sludge of step a).

Embodiments of the disclosure pertain to an apparatus comprising a phase separator configured to separate a mixture comprising (i) water containing NaCl and (ii) oil and/or gas into separate streams comprising the water, the oil (when oil is in the mixture), and the gas (when gas is in the mixture), an electrochemical membrane separation cell configured to separate sodium and chloride ions in the water stream to form a stream comprising a first sodium hydroxide solution and a stream comprising (i) hydrochloric acid and/or (ii) chlorine gas, a compressor configured to compress a gas containing CO.sub.2, a spray dryer configured to mix aqueous NaOH and the compressed gas to form sodium carbonate, and a cyclone separator configured separate the sodium carbonate from any excess components of the aqueous NaOH and/or the compressed gas.

The present disclosure relates to a method of generating high-purity hydrogen from waste plastic without producing carbon dioxide. In the method of generating hydrogen according to the embodiments of the present disclosure, reactants include hydroxide, and thus, the amount and purity of the generated hydrogen increases, a reaction temperature suitable for reaching an appropriate hydrogen production rate is lowered, and the amount of generated carbon dioxide is significantly decreased.