Various embodiments of a portable carbon dioxide (CO2) absorption device that may remove excess CO2 from a closed environment are disclosed herein. The absorption device is reusable and configured for many environments.

An absorbent liquid which absorbs at least one of CO.sub.2 and H.sub.2S from a gas, including a secondary linear monoamine; a tertiary linear monoamine or a sterically hindered primary monoamine; and a secondary cyclic diamine, wherein a concentration of each of the secondary linear monoamine, the tertiary linear monoamine or the sterically hindered primary monoamine; and the secondary cyclic diamine is less than 30% by weight.

Disclosed herein are acid gas absorbents that afford high acid gas (CO2) absorption amount per unit volume and high absorption speed and can prevent the absorbent. components from diffusing. The acid gas absorbent contains an amine compound of the form is (1) and a cyclic amine compound of the formula (3) or (3):

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Disclosed herein are acid gas absorbents that afford high acid gas (CO2) absorption amount per unit volume and high absorption speed and can prevent the absorbent components from diffusing. Also disclosed herein is a method and device for removing an acid gas, in which the energy required for separating the acid gas and regenerating the absorbent is reduced, are provided.

The embodiments provide an acidic gas absorbent, an acidic gas removal method, and an acidic gas removal apparatus. The absorbent absorbs an acidic gas in a large amount and hardly diffuses in air. The acidic gas absorbent according to the embodiment comprises an amine compound having a sulfonyl group and two or more amino groups.

Certain functionalized aldehydes scavengers may be used to at least partially scavenge sulfur-containing contaminants from fluid systems containing hydrocarbons and/or water. The contaminants scavenged or otherwise removed include, but are not necessarily limited to, H.sub.2S, mercaptans, and/or sulfides. Suitable scavengers include, but are not necessarily limited to, reaction products of glycolaldehyde with aldehydes; reaction products of glycolaldehyde with a nitrogen-containing reactant (e.g. an amine, a triazine, an imine, an aminal, and/or polyamines); non-nitrogen-containing reaction products of a hydrated aldehyde with certain second aldehydes; reaction products of 1,3,5-trioxane with hydroxyl-rich compounds (e.g. glyoxal, polyethylene glycol, polypropylene glycol, pentaerythritol, and/or sugars); and reaction products of certain aldehydes with certain phenols; and combinations of these reaction products.

The present invention relates to a method for regenerating an acid gas absorbent using Ag.sub.2O and Ag.sub.2CO.sub.3 mixed catalyst in an acid gas absorbent regeneration process in an acid gas capture process using an amine absorbent absorbing acid gas. Regeneration method of carbon dioxide absorbent using Ag.sub.2O and Ag.sub.2CO.sub.3 mixed catalyst of the present invention promotes the decomposition of carbon dioxide-bound carbamate from the carbon dioxide-absorbed absorbent of Ag.sub.2O and Ag.sub.2CO.sub.3 mixed catalysts through a novel catalytic reaction pathway to remove efficiently.

Carbon dioxide is separated from a flue gas by scrubbing the gas with an aqueous solution of an amine and a salt, the CO2 is thereafter released from the solution by heating. The scrubbing step is performed with a co-current gravity fed stream of an aqueous solution of the amine and a salt of the gas and solution through an absorption column.

A carbon dioxide separation and capture apparatus includes an absorption tower configured to cause an absorbing liquid to absorb a carbon dioxide gas contained in a process gas and a regeneration tower configured to cause the absorbing liquid from the absorption tower to release the carbon dioxide gas. The carbon dioxide separation and capture apparatus further includes an inlet concentration meter configured to measure concentration of an acid component in the process gas supplied to the absorption tower and an outlet concentration meter configured to measure concentration of the acid component in the process gas discharged from the absorption tower. Also included in the carbon dioxide separation and capture apparatus are a supplementary absorbing liquid supply mechanism configured to supply a supplementary absorbing liquid to the main unit and a controller configured to control an amount of the supplementary absorbing liquid supplied to the main unit by the supplementary absorbing liquid supply mechanism based on the concentrations of the acid component measured at the inlet concentration meter and the outlet concentration meter.

A method of capturing a target species from a gas comprises the steps of: contacting a gas containing a target species with a first absorbent solution comprising a capture species; dissolving the target species in the first absorbent solution to form a target anion; electrochemically separating the target anion from the first absorbent solution by contacting the first absorbent solution with one or more ion-exchange membranes, and transferring the target anion through an ion-exchange membrane into a second absorbent solution; and releasing at least some of the target species from the second absorbent solution. The one or more ion-exchange membranes are not permeable to the capture species, so the capture species does not pass through the one or more ion-exchange membranes. An apparatus for capturing a target species from a gas is also provided.