Industrial & Engineering Chemistry Research, Vol.51, No.23, 8108-8116, 2012
Industrial Applied and Modeling Research on Selective H2S Removal Using a Rotating Packed Bed
For the simultaneous absorption of H2S and CO2 into methyldiethanolamine (MDEA) solution, MDEA in fact is selective toward both H2S and CO2. It is kinetically selective toward H2S and thermodynamically selective toward CO2. Selective H2S removal using a rotating packed bed (RPB) solves the problem that a large amount of CO2 accompanying H2S is simultaneously removed in the conventional desulfurization process. An RPB highlights that MDEA is kinetically selective toward H2S and restricts its thermodynamically selectivity toward CO2. In this work, an industrial test for MDEA selective absorption of H2S was performed. Compared with a conventional tower the RPB has a substantial advantage in selective absorption of H2S. A reaction equilibrium mass transfer model based on penetration theory is developed to describe the selective absorption process and the inhibition effect on H2S absorption from the CO2-MDEA reaction in the liquid film.