Absorption of H 2S and CO 2 in aqueous phosphate solutions

Abstract

Absorption rates of CO 2 and H 2S into aqueous solutions of K 3PO 4 and K 2HPO 4 have been measured using a ‘wetted wall’ absorber. The absorption rate of either CO 2 alone or H 2S alone can be predicted theoretically and has been confirmed experimentally. In the case of simultaneous absorption of both gases, one can qualitatively predict that the H 2S absorption is not influenced by the presence Of CO 2 while the CO 2 absorption is effectively reduced by the action of H 2S. This prediction also is confirmed by experiments. Very high selectivity for H 2S is obtained with this system. The interest in the use of buffer phosphate solutions is also due to the fact that P 2O 5 is non-volatile