SYSTEM FOR RECOVERING HIGH-PURITY CO2 FROM GASIFICATION GAS CONTAINING CO, CO2, COS AND H2S

摘要

A method and system for recovering CO₂ from gasification gas, prevents the recovered CO₂ from being contaminated with COS, without repeating cooling and heating operations and without increasing the steam consumption. Gasification gas being produced in a gasifier 10 and containing CO, CO₂, COS and H₂S is subjected to dust removal in a scrubber 20. Then, a part of the gas is subjected to a CO shift reaction, in which CO is converted into CO₂, in a CO shift reactor 30. Another part of the gasification gas is not subjected to the CO shift reaction by means of a bypass 34, and is mixed with the gas after the CO shift reaction. Thereby, the temperature of the mixture gas is set at 180° C. to 300° C., and COS in the mixture gas is converted into H₂S in a COS converter 40.