A process for desorbing CO.sub.2 gas from an ion-rich aqueous mixture comprising bicarbonate and hydrogen ions, includes providing micro-particles in the ion-rich aqueous mixture; and feeding the ion-rich aqueous mixture into a desorption reactor; the micro-particles comprising a support material and biocatalysts supported and stabilized by the support material and being sized and provided in a concentration in the desorption reactor such that the micro-particles are carried with the ion-rich aqueous mixture to promote transformation of the bicarbonate and hydrogen ions into CO.sub.2 gas and water, thereby producing a CO.sub.2 gas stream and an ion-depleted solution.

A formulation and process for capturing CO.sub.2 use an absorption mixture containing water, biocatalysts and a carbonate compound. The process includes contacting a CO.sub.2-containing gas with the absorption mixture to enable dissolution and transformation of CO.sub.2 into bicarbonate and hydrogen ions, thereby producing a CO.sub.2-depleted gas and an ion-rich solution, followed by subjecting the ion-rich solution to desorption. The biocatalyst improves absorption of the mixture comprising carbonate compounds and the carbonate compound promotes release of the bicarbonate ions from the ion-rich solution during desorption, producing a CO.sub.2 gas stream and an ion-depleted solution.

A processing unit for a liquid washing medium contaminated with sulphur oxides and/or nitrogen oxides, has an evaporation stage for concentrating the active components of the washing medium by an evaporator and/or by a heat exchanger, and has a collecting tank connected to the evaporator and/or to the heat exchanger. The collecting tank is configured as a crystallizer for removing sulfur oxides from the washing medium by crystallization of a sulphate, in particular of potassium sulphate. A separating device for carbon dioxide has a corresponding processing unit, and a method for processing a washing medium contaminated with sulphur oxides and/or nitrogen oxides uses a corresponding processing unit.

An air pollution control system includes: a desulfurization device which removes sulfur oxides in a flue gas generated from a boiler; a cooler which is provided at the downstream side of the desulfurization device, decreases a flue gas temperature and enlarges a particle diameter of SO.sub.3 mist contained in the flue gas through cooling or heating the flue gas by a temperature adjustment means for adjusting a gas dew point temperature of the flue gas; and a CO.sub.2 recovery device which includes a CO.sub.2 absorber bringing CO.sub.2 in the flue gas into contact with the CO.sub.2 absorbent so as to remove CO.sub.2 therefrom and a regenerator recovering CO.sub.2 by dissociating CO.sub.2 from the CO.sub.2 absorbent and regenerating the CO.sub.2 absorbent, wherein the flue gas is cooled by a cooling unit so as to enlarge the SO.sub.3 mist in the flue gas.

An absorber of a carbon dioxide capture system according to an embodiment includes: a release region for releasing carbon dioxide from an absorbing liquid supplied from a stripper; and a second gas-liquid contact unit to which carbon dioxide released in the release region is supplied together with exhaust gas discharged from a first gas-liquid contact unit. The absorbing liquid having released the carbon dioxide therefrom in the release region is supplied to the second gas-liquid contact unit by an absorbing liquid supply device. The absorbing liquid having passed through the second gas-liquid contact unit is guided to the first gas-liquid contact unit while bypassing the release region. The second gas-liquid contact unit brings the exhaust gas and the absorbing gas into contact with each other so as to cause the carbon dioxide contained in the exhaust gas to be absorbed in the absorbing liquid.

A formulation and process for capturing CO.sub.2 use an absorption mixture containing water, biocatalysts and a carbonate compound. The process includes contacting a CO.sub.2-containing gas with the absorption mixture to enable dissolution and transformation of CO.sub.2 into bicarbonate and hydrogen ions, thereby producing a CO.sub.2-depleted gas and an ion-rich solution, followed by subjecting the ion-rich solution to desorption. The biocatalyst improves absorption of the mixture comprising carbonate compounds and the carbonate compound promotes release of the bicarbonate ions from the ion-rich solution during desorption, producing a CO.sub.2 gas stream and an ion-depleted solution.

A solvent formulation for the direct air capture of carbon dioxide is provided. The solvent formulation includes an amino acid salt, a polar solvent and an antifreeze agent. A direct air capture system for the direct air capture of carbon dioxide is further provided. The direct air capture system incudes a desorption column, a gas separator, and an air contactor. The desorption column, gas-liquid separator, and air contactor are in fluid communication. The air contactor includes the solvent formulation.

In a general aspect, a carbon dioxide removal system is presented. In some cases, a gas-liquid contactor is wetted with an alkaline capture solution. A first flow from a first gaseous feed including CO.sub.2 from a first source is directed to interact with the alkaline capture solution in the gas-liquid contactor, which forms a first CO.sub.2-rich alkaline capture solution. A second flow from a second gaseous feed including CO.sub.2 from a second, distinct source is directed to interact with the first CO.sub.2-rich alkaline capture solution, which forms a second CO.sub.2-rich alkaline capture solution. In some cases, the second flow is independent of the first gaseous feed, and a concentration of CO.sub.2 in the second CO.sub.2-rich alkaline capture solution is higher than a concentration of CO.sub.2 in the first CO.sub.2-rich alkaline capture solution. CO.sub.2 can be separated from the second CO.sub.2-rich alkaline capture solution.

A process of regeneration of a capture medium rich in a captured target gas comprising the steps of: heating a target gas rich capture medium comprising an absorbent medium, absorbed target gas and water using thermal energy, thereby facilitating the separation of the absorbed target gas from the capture medium into a gas containing vapour phase and a heated lean capture medium, said gas containing vapour phase comprising the target gas and water vapour having a steam fraction of at least 0.8; compressing at least one of: the gas containing vapour phase; or a vapour phase thermally associated with the gas containing vapour phase, to form a compressed vapour; and using the compressed vapour as a source of thermal energy to heat the target gas rich capture medium.

Amine-based solvents, carbon dioxide capture systems, and methods for improving stability of carbamate during carbon dioxide capture are disclosed herein. The amine-based solvents comprise at least one cyclic amine having a first molecular site that is structurally modified to be protonated and a second molecular site that is structurally modified to hold carbon dioxide as carbamate. The carbon dioxide capture systems comprise at least one gaseous stream comprising carbon dioxide and the amine-based solvent in contact with the at least one gaseous stream. The methods for carbon dioxide capture comprise contacting at least one modified cyclic amine to a gaseous stream comprising carbon dioxide such that the modified at least one cyclic amine chemically reacts with carbon dioxide to form a soluble compound.