Abstract: A description is given of the use of an alkylenediamine of the type R1HN—X—NHR2, where X is an alkylene radical having from 2 to 9 carbons, R1 is a hydrocarbon radical having from 1 to 6 carbons and R2 is a hydrocarbon radical having from 1 to 6 carbons or is hydrogen (H) for removing sour gases from a sour-gas-containing fluid stream, and of a process for deacidifying a fluid stream of this type and a wash liquid or absorption liquid for use in such a process. According to the invention, in at least one absorption step, the fluid stream is brought into intimate contact with a wash liquid, the wash liquid comprising an aqueous amine solution which comprises at least one tertiary aliphatic alkanolamine having from 2 to 12 carbons and an activator of the above type R1HN—X—NHR2. The fluid stream which is substantially freed from sour gases and the sour-gas-loaded wash liquid are then separated from one another.

Abstract: A process is described for removing acid gases from a gas stream in which an acid-gas-containing gas stream in which the sum of the partial pressures of the acid gases does not exceed 1 500 mbar is brought into contact with an aqueous absorbent in an absorption step and an absorbent is used which contains methyldiethanolamine and piperazine at a concentration of at least 8% by weight of the absorbent, an acid-gas-depleted gas stream and an acid-gas-loaded absorbent being obtained.

Abstract: A description is given of the use of an alkylenediamine of the type R1HN—X—NHR2, where X is an alkylene radical having from 2 to 9 carbons, R1 is a hydrocarbon radical having from 1 to 6 carbons and R2 is a hydrocarbon radical having from 1 to 6 carbons or is hydrogen (H) for removing sour gases from a sour-gas-containing fluid stream, and of a process for deacidifying a fluid stream of this type and a wash liquid or absorption liquid for use in such a process. According to the invention, in at least one absorption step, the fluid stream is brought into intimate contact with a wash liquid, the wash liquid comprising an aqueous amine solution which comprises at least one tertiary aliphatic alkanolamine having from 2 to 12 carbons and an activator of the above type R1HN—X—NHR2. The fluid stream which is substantially freed from sour gases and the sour-gas-loaded wash liquid are then separated from one another.

Abstract: A process for removing acidic gas constituents, of the group consisting of CO2, H2S, COS, CS2 and mercaptans, from gases, in which, in an absorption step, a dirty gas rich in acidic gas constituents is brought into contact with an absorption medium, as a result of which a clean gas low in acidic gas constituents and an absorption medium laden with acidic gas constituents are obtained, the absorption medium used being a mixture comprising a) from 0.1 to 50% by weight of one or more mono-cyclic or bicyclic nitrogen heterocycles which are unsubstituted and/or monosubstituted or poly-substituted on the carbon by OH, C1-C3 alkyl and/or C1-C3 hydroxyalkyl and which have from 5 to 14 ring atoms and 1 or 2 heterocyclically bound nitrogen atoms per ring as component A, b) from 1 to 60% by weight of a monohydric and/or polyhydric alcohol as component B, c) from 0 to 60% by weight of an aliphatic aminoalcohol as component C, d) from 0 to 98.