SEPARATION OF CARBON DIOXIDE AND HYDROGEN

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.