NOVEL PROCESS DESIGNS FOR INCREASED SELECTIVITY AND CAPACITY FOR HYDROGEN SULFIDE CAPTURE FROM ACID GASES

摘要

A system and process for selectively separating H2S from a gas mixture which also comprises CO2 is disclosed. A water recycle stream is fed to the absorber in order to create a higher concentration absorbent above the recycle feed and having a greater H2S selectivity at lower acid gas loadings, and a more dilute absorbent below the recycle feed and having a greater H2S selectivity at higher acid gas loadings. Also disclosed is a system and process for selectively separating H2S by utilizing two different absorbents, one absorbent for the upper section of the absorber, tailored to have a greater H2S selectivity at lower acid gas loadings, and a second absorbent for the lower section of the absorber, tailored to have a greater H2S selectivity at higher acid gas loadings.