INTEGRATED PROCESS TO RECOVER HIGH QUALITY NATIVE CO₂ FROM A SOUR GAS COMPRISING H₂S AND CO₂

摘要

The invention concerns a method for treating a hydrocarbon feed gas stream containing at least CO₂ and H₂S to recover a high quality purified CO₂ gas stream, comprising the following steps: a. separating said hydrocarbon feed gas stream into (i) a sweetened hydrocarbon gas stream, and (ii) an acid gas stream comprising at least CO₂ and H₂S; b. introducing said gas stream (ii) into a Claus unit, thereby recovering (iii) a liquid stream of elemental sulfur and (iv) a tail gas mainly comprising N₂, CO₂, SO₂ and H₂S; c. introducing the tail gas (iv) into a hydrogenation reactor and then into a quench contactor of the Tail Gas Treatment Unit (TGTU) thereby recovering (v) a hydrogenated tail gas stream mainly comprising N₂, H₂, CO, CO₂ and H₂S; d. contacting said tail gas stream (v) with a non-selective amine-based solvent into a non-selective acid gas absorption unit of the TGTU thereby recovering (vi) an off gas mainly comprising N₂, H₂ and CO and (vii) a gas stream enriched in CO₂ and H₂S; e. sending the off gas (vi) to an incinerator; f. contacting said enriched gas stream (vii) with a selective H₂S-absorption solvent into a selective H₂S-absorption unit thereby recovering (viii) a highly purified CO₂ gas stream and (ix) a H₂S-enriched gas stream, as well as the device for carrying said method.