| 摘要 |
In a system for the separation of sour gases especially hydrogen sulfide and carbon dioxide from a raw gaseous mixture e.g., hydrogen-containing in order to form a purified gaseous mixture, comprising scrubbing the gaseous mixture in a first scrubbing stage with a physical scrubbing liquid e.g., methanol having a higher absorbability for hydrogen sulfide than for carbon dioxide, withdrawing from the scrubbing stage a first stream of scrubbing liquid loaded with hydrogen sulfide and carbon dioxide, and regenerating the loaded scrubbing liquid to form (a) a gaseous phase containing hydrogen sulfide, and (b) regenerated scrubbing liquid, the improvement of scrubbing said gaseous phase containing hydrogen sulfide in a second scrubbing stage with a stream of scrubbing liquid capable of absorbing additional H2S, e.g., a CO2-depleted stream from an H2S enrichment column; and subjecting resultant second stream of scrubbing liquid loaded with hydrogen sulfide to a separation stage, preferably rectification, to form a bottoms of regenerated scrubbing liquid and an overhead of a gaseous phase rich in hydrogen sulfide irrespective of whether the raw gaseous mixture has a very low H2S concentration. |
