PROCESS AND PLANT FOR THE PURIFICATION OF RAW SYNTHESIS GAS

摘要

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.