A series of experiments on the facilitated transport of CO
2 through supported liquid membranes impregnated with aqueous solutions of various amines as carriers was performed, and the effects of the reaction rate and the chemical equilibrium of the reaction between CO
2 and amine on the permeability of CO
2 were investigated. Four primary amines (monoethanolarnine (MEA), ethylenediamine (EDA), monoprotonated ethylenediamine (EDAH
+), 2-amino-2-methyl-l-propanol (AMP)), one secondary amine (diethanolamine (DEA)) and two tertiary amines (triethanolamine (TEA), methyldiethanolamine (MDEA)) were used as the carrier. The feed gas was a mixture of CO
2 and CH
4. High CO
2 permeabilities were obtained with the EDAH
+ membrane due to its moderate chemical equilibrium constant
Keq which is favorable for both fast absorption of CO
2 at the feed side of the membrane and fast stripping at the sweep side. Low CO
2 permeabilities were obtained with the tertiary amine and AMP membranes due to their low reactivity. The CO
2 permeability through the MEA membrane, which has too large a
Keq value at low temperature, increased with increasing temperature due to the decrease in
Keq and also due to the increase in the reaction rate. The experimental results obtained with the MEA, DEA and EDAH
+ membranes were simulated on the basis of the theory of facilitated transport.
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