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Abstract

A process is described for separating a gas stream containing hydrogen sulfide (H₂S) impurities into a hydrogen (H₂) rich vapor stream, a carbon dioxide (CO₂) stream and an H₂S rich vapor stream in an apparatus that comprises a compression and/or cooling system comprising at least one compressor and/or heat exchanger and a gas-liquid separator vessel, and an H₂S recovery unit. In examples, the process comprises the steps of: (a) feeding the gas stream to the compression and/or cooling system such that carbon dioxide in the gas stream condenses to form a two-phase stream; (b) passing the two-phase stream either directly or indirectly to a gas-liquid separator vessel and withdrawing a hydrogen rich vapor stream and a liquid CO₂ stream containing dissolved H₂S impurities from the separator vessel; (c) passing the liquid CO₂ stream containing dissolved H₂S impurities to an H₂S recovery unit comprising an evaporator/condenser in which the CO₂ and H₂S are vaporized and an H₂S absorber in which the gaseous H₂S and CO₂ are separated, wherein the two phase stream passed to the separator is at a pressure of from 80 bar to 400 bar. In some applications, the pressure of the H₂S recovery unit is at least 30 bar. In a preferred example, residual CO₂ in the hydrogen rich vapor stream is removed in an optional step by solvent extraction in a CO₂ absorber most preferably in a configuration where the H₂S and CO₂ absorbers share the same (preferably methanol) solvent.

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First Claim