Abstract: An absorbent for selective removal of hydrogen sulfide over carbon dioxide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I) in which R1 and R2 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; R3, R4, R5 and R6 are each independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl, with the proviso that at least one R4 and/or R5 radical on the carbon atom bonded directly to the nitrogen atom is C1-4-alkyl or C1-4-hydroxyalkyl when R3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol.

Abstract: In a process for removal of acid gases from a fluid stream the fluid stream is contacted with an absorbent to obtain a treated fluid stream and a laden absorbent.

Abstract: The use of an amine of the formula (I) in which the R1 to R5 radicals are each as defined in the description, and an absorbent and a process for removing acidic gases from a fluid stream, especially for selectively removing hydrogen sulfide over carbon dioxide. The invention also relates to particular amines suitable for selective removal of hydrogen sulfide. Absorbents based on amines of the formula (I) have high selectivity, high loading capacity and good regeneration capacity.

Abstract: An absorbent for selective removal of hydrogen sulfide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I) in which R1 and R2 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; R3, R4, R5 and R6 are each independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl, with the proviso that at least one R4 and/or R5 radical on the carbon atom bonded directly to the nitrogen atom is C1-4-alkyl or C1-4-hydroxyalkyl when R3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol.

Abstract: A process for removing hydrogen sulfide and carbon dioxide from a fluid stream comprises a) an absorption step in which the fluid stream is contacted with an absorbent comprising an aqueous solution (i) of an amine of the general formula (I) in which R1, R2 and R3 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; X is OH or NH(CR1R2R3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and optionally (ii) at least one tertiary amine, where the molar ratio of (i) to (ii) is greater than 0.

Abstract: An absorbent for removing carbon dioxide from a fluid stream, comprising an aqueous solution a) of an amine of the general formula (I) in which R1, R2 and R3 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; X is OH or NH(CR1R2R3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and b) at least one activator selected from b1) a sterically unhindered primary amine and/or a sterically unhindered secondary amine; and a carboanhydrase. The absorbent allows rapid absorption of carbon dioxide from fluid streams.

Abstract: A premixture for producing an absorbent for removing acid gases from a fluid stream containing a) at least a tertiary amine and/or a sterically hindered secondary amine; b) a dicarboxylic acid in an amount, calculated as neutralization equivalent based on the protonatable nitrogen atoms in a), of at least 30%, wherein the dicarboxylic acid has a solubility in water at a temperature of 20° C. of not more than 15 g of dicarboxylic acid per 100 g of water; and c) 20 to 80 wt % of water. Also described is a process for producing an absorbent from the premixture. The premixture is a transportable and readily handleable solution of a dicarboxylic acid having poor solubility in water for producing an absorbent for removing acid gases from a fluid stream.

Abstract: A compound of the general formula (I) in which R1, R2 and R3 are independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is an integer from 0 to 10. A preferred compound of the formula (I) is 2-(2-tert-butylaminoethoxy)ethylamine. Absorbents comprising a compound of the formula (I) have rapid absorption of carbon dioxide from fluid streams and are also suitable for processes for the simultaneous removal of H2S and CO2, where given H2S limits have to be observed but complete removal of CO2 is not required.

Abstract: A process for removing hydrogen sulfide and carbon dioxide from a fluid stream comprises a) an absorption step in which the fluid stream is contacted with an absorbent comprising an aqueous solution (i) of an amine of the general formula (I) in which R1, R2 and R3 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; X is OH or NH(CR1R2R3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and optionally (ii) at least one tertiary amine, where the molar ratio of (i) to (ii) is greater than 0.

Abstract: An absorbent for selective removal of hydrogen sulfide from a fluid stream comprises an aqueous solution comprising a) a tertiary amine; b) an aminic pH promoter selected from the compounds mentioned in the description; where the molar ratio of b) to a) is in the range from 0.05 to 1.0; and c) an acid having a pKA of less than 6 in such an amount that the pH of the aqueous solution measured at 120° C. is 7.9 to less than 8.8. Also described is a process for removing acidic gases from a fluid stream, in which the fluid stream is contacted with the absorbent. The absorbent is notable for a low regeneration energy.

Abstract: An absorbent for selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide comprises a) an amine compound of the formula (I) in which X, R1 to R7, x, y and z are as defined in the description; and b) a nonaqueous solvent; where the absorbent comprises less than 20% by weight of water. Also described is a process for selectively removing hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, wherein the fluid stream is contacted with the absorbent. The absorbent features high load capacity, high cyclic capacity, good regeneration capacity and low viscosity.

Abstract: The use of an amine of the formula (I) in which the R1 to R5 radicals are each as defined in the description, and an absorbent and a process for removing acidic gases from a fluid stream, especially for selectively removing hydrogen sulfide over carbon dioxide. The invention also relates to particular amines suitable for selective removal of hydrogen sulfide. Absorbents based on amines of the formula (I) have high selectivity, high loading capacity and good regeneration capacity.

Abstract: A compound of the general formula (I) in which R1 to R8, x, y and z are as defined in the description. Also described is an absorbent comprising a solution of the compound, and the use thereof and a process for removing acid gases from a fluid stream, wherein the fluid stream is contacted with the absorbent. The compounds of the general formula (I) are notable for thermal stability and low volatility. Absorbents based on the compounds are notable for high loading capacity, high cyclic capacity and good regeneration capacity. The solutions of the compounds in nonaqueous solvents are notable for low viscosities.

Abstract: An absorbent for selective removal of hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, which comprises a) 10% to 70% by weight of at least one sterically hindered secondary amine having at least one ether group and/or at least one hydroxyl group in the molecule; b) at least one nonaqueous solvent having at least two functional groups selected from ether groups and hydroxyl groups in the molecule; and c) optionally a cosolvent; where the hydroxyl group density of the absorbent ?abs is in the range from 8.5 to 35 mol(OH)/kg. Also described is a process for selectively removing hydrogen sulfide from a fluid stream comprising carbon dioxide and hydrogen sulfide, wherein the fluid stream is contacted with the absorbent. The absorbent features good regeneration capacity and high cyclic acid gas capacity.

Abstract: A compound of the general formula (I) in which R1, R2 and R3 are independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is an integer from 0 to 10. A preferred compound of the formula (I) is 2-(2-tert-butylaminoethoxy)ethylamine. Absorbents comprising a compound of the formula (I) have rapid absorption of carbon dioxide from fluid streams and are also suitable for processes for the simultaneous removal of H2S and CO2, where given H2S limits have to be observed but complete removal of CO2 is not required.

Abstract: An absorbent for selective removal of hydrogen sulfide from a fluid stream comprises an aqueous solution of a) a tertiary amine, b) a sterically hindered secondary amine of the general formula (I) in which R1 and R2 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; R3, R4, R5 and R6 are each independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl, with the proviso that at least one R4 and/or R5 radical on the carbon atom bonded directly to the nitrogen atom is C1-4-alkyl or C1-4-hydroxyalkyl when R3 is hydrogen; x and y are integers from 2 to 4 and z is an integer from 1 to 4; where the molar ratio of b) to a) is in the range from 0.05 to 1.0, and c) an acid in an amount, calculated as neutralization equivalent relative to the protonatable nitrogen atoms in a) and b), of 0.05 to 15.0%. One preferred amine of the formula I is 2-(2-tert-butylaminoethoxy)ethanol.

Abstract: A process for removing acid gases from a water vapor-containing fluid stream comprises a) providing an absorption liquid which is incompletely miscible with water; b) treating the fluid stream in an absorption zone with the absorption liquid to obtain an acid gas-depleted treated fluid stream and an acid gas-loaded absorption liquid; c) directing the treated fluid stream to a rehydration zone and treating the fluid stream with an aqueous liquid to volatilize at least part of the aqueous liquid; d) regenerating the loaded absorption liquid to expel the acid gases at least in part and obtain a regenerated absorption liquid, and directing the regenerated absorption liquid to step b); and e) separating, from the absorption liquid, an aqueous liquid that has condensed in the absorption zone, and directing the aqueous liquid to step c). The process allows for an efficient removal of water accumulated in the absorption liquid system.

Abstract: A process for removing hydrogen sulfide and carbon dioxide from a fluid stream comprises a) an absorption step in which the fluid stream is contacted with an absorbent comprising an aqueous solution (i) of an amine of the general formula (I) in which R1, R2 and R3 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; X is OH or NH(CR1R2R3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and optionally (ii) at least one tertiary amine, where the molar ratio of (i) to (ii) is greater than 0.

Abstract: An absorbent for removing carbon dioxide from a fluid stream, comprising an aqueous solution a) of an amine of the general formula (I) in which R1, R2 and R3 are each independently selected from C1-4-alkyl and C1-4-hydroxyalkyl; each R4 is independently selected from hydrogen, C1-4alkyl and C1-4-hydroxyalkyl; each R5 is independently selected from hydrogen, C1-4-alkyl and C1-4-hydroxyalkyl; X is OH or NH(CR1R2R3); m is 2, 3, 4 or 5; n is 2, 3, 4 or 5; and o is 0 or 1; and b) at least one activator selected from b1) a sterically unhindered primary amine and/or a sterically unhindered secondary amine; and a carboanhydrase. The absorbent allows rapid absorption of carbon dioxide from fluid streams.

Abstract: A process for separating off acid gases from a nitrogen oxide-comprising fluid stream, wherein a) the fluid stream is brought into contact in an absorption zone with an aqueous absorbent which comprises at least one amino group-comprising compound, wherein a deacidified fluid stream is obtained, b) the deacidified fluid stream is brought into contact in at least one scrubbing zone with an aqueous scrubbing liquid and a de-aminated deacidified fluid stream is obtained, wherein the scrubbing liquid is recycled via at least one scrubbing zone, c) overflow from the at least one scrubbing zone is treated with UV light, and d) the UV-treated overflow is combined with the absorbent. The process permits the efficient degradation of the nitrosamines present in the absorbent.