Patent ID: 9731974
Date: 2017-08-15
CPC Classifications: B01D,B01J,C01B,C01P,C10L,Y02P

Claim:
1. A method for treating a hydrocarbon feed gas stream containing at least carbon dioxide and hydrogen sulfide to recover a high quality purified CO 2 gas stream, said process 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 carbon dioxide and hydrogen sulfide; b. Introducing said acid gas stream (ii) into a Claus unit, thereby recovering (iii) a liquid stream of elemental sulfur and (iv) a tail gas mainly comprising nitrogen, carbon dioxide, sulfur dioxide and hydrogen sulfide; 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 comprising nitrogen, hydrogen, carbon monoxide, carbon dioxide and hydrogen sulfide; d. Contacting said hydrogenated tail gas (v) with a non-selective amine-based solvent into a non-selective acid gas absorption unit of the TGTU, said non-selective amine-based solvent adsorbing both carbon dioxide and hydrogen sulfide, thereby recovering (vi) an off gas comprising nitrogen, hydrogen and carbon monoxide and (vii) a gas stream enriched in carbon dioxide and hydrogen sulfide; 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 CO