Use of Sulfurihydrogenibium sp. carbonic anhydrase (SspCA) or mutants thereof for catalyzing the hydration reaction of CO.sub.2 into bicarbonate and hydrogen ions or catalyzing the desorption reaction to produce a CO.sub.2 gas is provided.

According to one embodiment of the present invention, an apparatus for carbon dioxide capture includes an absorption tower in which an absorbent absorbs carbon dioxide contained in exhaust gas to thereby form a saturated absorbent; a stripping tower in which the carbon dioxide is stripped from the saturated absorbent transferred from the absorption tower and the absorbent is regenerated; a first heat exchanger configured to preheat the saturated absorbent while the saturated absorbent is being transferred from the absorption tower to the stripping tower; and a second heat exchanger configured to secondarily preheat the primarily preheated saturated absorbent.

A device for separating carbon dioxide from a gas flow, in particular from a flue gas flow, having an absorption unit for separating carbon dioxide from the gas flow using a scrubbing medium, a desorption unit which is fluidically connected to the absorption unit for releasing the absorbed carbon dioxide from the scrubbing medium, and a compressor unit which is connected fluidically downstream of the desorption unit for compressing the released carbon dioxide, the compressor unit being connected fluidically upstream of a cleaning device for the carbon dioxide. A method separates carbon dioxide from a gas flow, in particular from a flue gas flow.

A composition and a device for purification of nitrogen-oxide-containing gas is provided. It can purify harmful nitrogen-oxide-containing gases, such as nitric oxide or nitrogen dioxide. The composition includes an alkaline substance and at least one organic acid, the organic acids having an enediol group, enediamine group, or amine group of cyclopentane compounds, cyclohexane compounds, cycloheptane compounds, or phenanthrene compounds.

Disclosed herein is a porous material comprising a biopolymer functionalized with a carbon dioxide capturing moiety; where the biopolymer is in the form of a foam or an aerogel having a bulk density of 500 grams per cubic meter to 2500 grams per cubic meter. Disclosed herein too is a method comprising functionalizing a biopolymer with a carbon dioxide capturing moiety; dissolving the biopolymer in an aqueous solution to form a first solution; reducing the temperature of the first solution to below the freezing point of the aqueous solution; displacing the aqueous solution with a first solvent that has a lower surface tension than a surface tension of the aqueous solution; and drying the first solvent to produce a porous biopolymer having a bulk density of 500 grams per cubic meter to 2500 grams per cubic meter.

The absorption of CO.sub.2 from a gas mixture by contacting the gas mixture with an absorption medium that comprises water and 5 to 50 wt % of amino acid salts of formula R.sup.1R.sup.2CHNHCH.sub.2COOK, in which R.sup.1 and R.sup.2 are n-alkyl radicals and the radicals R.sup.1 and R.sup.2 together have 2 to 4 carbon atoms, affords a high CO.sub.2 absorption capacity per unit weight in the cyclical operation of absorption and desorption.

In a general aspect, interfacial surface structures for removing carbon dioxide from a gaseous feed are presented. In some cases, a method of removing carbon dioxide gas from a gaseous feed includes wetting surfaces of an interfacial surface structure in a gas-liquid contactor with an alkaline capture solution. The gaseous feed containing the CO.sub.2 gas is passed across the wetted surfaces of the interfacial surface structure to dissolve the CO.sub.2 gas in the alkaline capture solution. A CO.sub.2-rich alkaline capture solution is collected from the gas-liquid contactor. The CO.sub.2-rich alkaline capture solution includes dissolved CO.sub.2 gas from the gaseous feed.

A method for separating carbon dioxide from a gas stream, in particular from a flue gas stream, wherein, a gas stream is brought into contact with a washing medium in an absorber of a separation device and the carbon dioxide contained in the gas stream is separated; the charged washing medium is supplied to a desorber of the separation device to release the carbon dioxide; a vapor stream is removed from the desorber and is supplied to a cooling unit to form a condensate; degradation products, in particular nitrosamines, contained in at least a partial stream of the condensate are photolytically decomposed to decomposition products; at least the decomposition products, in particular nitrites and amines, are removed; and at least a partial stream of the condensate is returned to the desorber. A corresponding separation device separates carbon dioxide from a gas stream.

The present invention relates to an absorbent, an absorbent system and a process for removing acidic gas such as CO.sub.2 from exhaust gases from fossil fuel fired power stations, from natural gas streams, from blast furnace oven off-gases in iron/steel plants, from cement plant exhaust gas and from reformer gases containing CO.sub.2 in mixtures with H.sub.2S and COS. The liquid absorbent, a mixture of amine and amino acid salt is contacted with a CO.sub.2 containing gas in an absorber and CO.sub.2 in the gas stream is absorbed into the liquid. The absorbed CO.sub.2 forms more than one type of solid precipitate in the liquid at different absorption stages. In a first absorption stage solid precipitate of amine bicarbonate is formed and is withdrawn as slurry from the bottom of a first absorber section. In a second absorption stage solid precipitate of alkali metal bicarbonate is formed and withdrawn as slurry at the bottom of a second absorber section. The slurry withdrawn from the first absorption section is heated to dissolve the precipitate with CO.sub.2 release in an amine flash regeneration tank. The slurry from the second precipitation stage is withdrawn from the bottom of the second absorber section and sent to a regenerator for desorption with CO.sub.2 release. The lean amine and amino acid salt mixture from the flash regenerator and desorber are mixed and returned to the top of the absorber. This absorbent system improves carbon dioxide removal efficiency due to its higher CO.sub.2 removal ability per cycle when compared with conventional amine, absorbent from organic acid neutralized with inorganic base and carbonate based absorbent system. It exhibits less solvent vaporization loss because part of the absorbent is in salt form.

The invention discloses methods and apparatus(es) for the removal and control of pollutants such as gases and suspended particulates in the air of an enclosed space or an outdoor environment by passing the air through absorbent media. The absorbent media includes any liquid, solid or combination of liquid and solid media that is capable of absorbing a material in which it comes in contact. In one aspect of the invention, formaldehyde is removed by air sparging through a liquid such as water, optionally containing additional scavenging agents.