Selective removal of hydrogen sulfide from carbon dioxide containing gases with methyldiethanolamine (MDEA) aqueous solutions

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5724382

Yu, W C

The kinetics of the chemical reactions between MDEA and H/sub 2/S can be regarded as instantaneous, since it is a proton-transfer reaction, and therefore these kinetics require no further investigation. The kinetics of the reaction between MDEA and CO/sub 2/ are more complicated and is studied here to clear the apparent contradiction in the literature (Barth et al., 1981; Blauwhoff et al., 1983). A base-catalyzed mechanism by MDEA is concluded with a kinetic equation which is first order in CO/sub 2/ and MDEA concentrations. The influence of ionic strength on these kinetics was studied, and it is concluded that a minor effect is indeed present. With the knowledge of the kinetics of these reactions, a model which describes the simultaneous absorption of H/sub 2/S and CO/sub 2/ in MDEA solutions is presented. This model can not only predict the simultaneous absorption of H/sub 2/S and CO/sub 2/ in the initial stage, but also predict an experimental observation of long time desorption of H/sub 2/S. Furthermore, this model provides analytical solutions of the mass transfer equations which take into account the interactions between the two chemical reactions. A special case, which is termed film effect, is taken into account in expanding the model into a design procedure. It is concluded that the film effect will be significant only at the lean end of the absorber. A linearized correction term is used to correct for this affect. Finally, the design procedures for both isothermal and adiabatic packed-bed absorbers are proposed on the basis of the simultaneous absorption model and the correction for film effect. No pilot plant data are included to check the calculation, because such data are not available in the open literature.

• Research Organization: Delaware Univ., Newark (USA)
• OSTI ID: 5724382
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
03 NATURAL GAS
CARBON DIOXIDE
REMOVAL
GASES
DESULFURIZATION
HYDROGEN SULFIDES
AMINES
CHEMICAL REACTION KINETICS
KINETIC EQUATIONS
MATHEMATICAL MODELS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
EQUATIONS
FLUIDS
HYDROGEN COMPOUNDS
KINETICS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SULFIDES
SULFUR COMPOUNDS
010402* - Coal
Lignite
& Peat- Purification & Upgrading
030300 - Natural Gas- Drilling
Production
& Processing