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):

##STR00001##

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.

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.

The invention relates to an absorbent solution and to a method using this solution for removing acid compounds contained in a gaseous effluent, comprising water and at least one diamine with general formula (I) as follows:

##STR00001## wherein: radicals R.sub.1, R.sub.2, R.sub.3 are each selected indiscriminately among a methyl radical and a hydroxyethyl radical, and at least one radical among R.sub.1, R.sub.2, R.sub.3 is a methyl radical.

The present invention relates to a carbon dioxide capture agent containing two types of amine compounds and a carbon dioxide capture method using the same, by which not only an effective and economically sustainable CO.sub.2 capture process can be performed but also an improved reaction rate is achieved.

The acid gas removal system for removing acidic gases from gaseous hydrocarbons (10) removes sour gases, such as hydrogen sulfide (H.sub.2S) and carbon dioxide (CO.sub.2), from an input gaseous stream. The system (10) includes a contactor (12) for contacting the input gaseous stream with an absorption liquid solvent (ALS), and a stripper (24) for recycling the absorption liquid solvent (ALS) and removing acidic gases (AG) therefrom, but with the addition of a pair of plate-plate heat exchangers (22, 26). The first heat exchanger (22) heats the used absorption liquid solvent (UALS) output from the contactor (12) prior to injection into the stripper (24). The used absorption liquid solvent (UALS) is heated via heat exchange with the acidic gases (AG) output from the stripper (24). The second heat exchanger (26) cools the recycled absorption liquid solvent (RALS) before injection back into the contactor (12).

A process for converting a feedstock comprising cyclic alkyleneureas into their corresponding alkyleneamines is provided. The process includes a CO.sub.2 removal step in which cyclic alkyleneureas are converted into their corresponding alkyleneamines by reacting cyclic alkyleneureas in the liquid phase with water with removal of CO.sub.2. The exemplary process further includes an amine removal step wherein cyclic alkyleneureas are converted in a reactive separation process into their corresponding alkyleneamines by reaction with an amine compound selected from the group of primary amines or secondary amines which have a higher boiling point than the alkyleneamines formed during the process.

The present disclosure relates to a hydroxyl group-containing amine-based sulfur dioxide and sulfurous absorbent, and a method for preparing the same. The absorbent uses an ionic liquid in the form of a salt including a diamine compound substituted with a hydroxyl group, and can be used as an absorbent capable of removing not only sulfur dioxide (SO.sub.2) but also sulfurous acid (H.sub.2SO.sub.3) formed by combination of sulfur dioxide with water.