Selective absorption of hydrogen sulfide and carbon dioxide into aqueous solutions of methyldiethanolamine

Abstract

A thermodynamic analysis of selectivity in both physical and chemical solvents is presented. For physical solvents, the process selectivity is only marginally different from the thermodynamic one; for chemical solvents, it may be much larger. The chemistry of C02 and K2S reactions in tertiary amine solutions is discussed; experiments show that tertiary amines may act as base catalysts for C02 hydration. A mass-transfer model which quantitatively predicts the H2S absorption rate in runs of simultaneous absorption is presented.

RETRACTED: Investigation of mixed amine solution in gas sweetening plant

“…The selective absorption characteristics of MDEA have been widely reported in the literature (Barth et al, 1981;Bullin and Polasek, 1982;Cornelissen, 1980;Danckwerts, 1979;Savage and Funk, 1981;Daviet et al, 1984;Ammons and Sitton, 1981;MacKenzie et al, 1987;Bullin et al, 1984). MDEA's selective absorption ability is due to its relatively slow reaction rate with CO 2 .…”

Thermodynamic modeling of hydrogen sulfide absorption by aqueous N-methyldiethanolamine using the Extended UNIQUAC model

“…In absorption processes, it might be advantageous to remove H 2 S selectively from the CO 2 /H 2 S mixture in the gas stream [3,4]. This owes to the fact that the absorbed H 2 S is often used as the feed to the Claus sulfur recovery plants or the feed for synthesis of sulfur containing products such as sulfuric acid, and hence, the presence of CO 2 deteriorates the by-product synthesis processes [3,4].…”

“…This owes to the fact that the absorbed H 2 S is often used as the feed to the Claus sulfur recovery plants or the feed for synthesis of sulfur containing products such as sulfuric acid, and hence, the presence of CO 2 deteriorates the by-product synthesis processes [3,4]. For H 2 S selective removal, MDEA is advantageous over other amines due to its ability to selectively remove H 2 S from gas streams [3,4].…”

Selective absorption of H2S from a gas mixture with CO2 in a microporous tube-in-tube microchannel reactor

“…The selectivity of amine solvents for H 2 S has been defined by previous workers [26] as the tendency for the ratio of H 2 S to CO 2 contents larger in the liquid phase than in the gas phase. The selectivity factor is used as a yardstick for H 2 S selectivity, and the value of selectivity factor S, which is dimensionless, is expressed as:…”