Process and plant for the purification of raw synthesis gas

Abstract

A process for the stepwise separation of accompanying gases from a raw synthesis gas stream by a liquid absorbent countercurrently guided through all process steps and circulated via regeneration plants, wherein either the accompanying gases H2S, COS and CO2 are separated in a common absorption step or, in one of the selective absorption steps chiefly H2S and COS are separated and in the next step in flow direction of the gas chiefly CO2 is separated, and in the last step a separation of accompanying gas residues (fine wash) is effected, wherein before the separation of H2S and COS an absorption step chiefly for the separation of aromatics and subsequently an absorption step chiefly for the separation of methyl mercaptan is carried out.

Dependencies are inferred from the claim text.