In the Acid Gas Removal (AGR) unit, the majority of the sulfur compounds and the carbon dioxide are removed from the process gas. This normally takes place by chemical and/or physical absorption of the compounds in a washing/scrubbing unit where methanol or an amine-based absorption medium is used.
The sulfur compounds removed in the AGR (mainly H2S with some COS) can be further processed to elemental sulfur using the Claus reaction or to sulfuric acid using Topsoe’s Wet Sulfuric Acid (WSA) process.
