| 摘要 |
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 0.3 to 0.7, and c) an acid in an amount, calculated as neutralization equivalents relative to the protonatable nitrogen atoms in a) and b), of 1.0 to 9.0%. One preferred amine of the formula is 2-(2-tert-butylaminoethoxy)ethanol. The absorbent allows a defined H2S selectivity to be set at pressures of the kind typical in natural gas processing. In addition, a process for removing acidic gases from a fluid stream having a partial H2S pressure of at least 0.1 bar and/or a partial CO2 pressure of at least 0.2 bar by means of this absorbent. |
