Patent ID: 8746009

Claim:
A process for the production of hydrogen from a gas mixture ( 21 ) comprising hydrogen, carbon dioxide, carbon monoxide, methane and water, employing a carbon dioxide PSA unit ( 30 ), a cryogenic unit ( 40 ) and an hydrogen PSA unit ( 50 ), in which: a) said gas mixture ( 21 ) is introduced into a carbon dioxide PSA unit ( 30 ), producing a carbon dioxide-enriched fraction ( 32 ) and a carbon dioxide-depleted fraction ( 31 ); b) the carbon dioxide enriched fraction ( 32 ) is introduced into a cryogenic unit ( 40 ), producing a carbon dioxide-enriched fraction ( 41 ) and a hydrogen-enriched fraction ( 43 ); c) the hydrogen-enriched fraction ( 43 ) is recycled upstream of the hydrogen PSA unit ( 50 ); and d) the carbon dioxide-depleted fraction ( 31 ) is introduced into the hydrogen PSA unit ( 50 ), producing a hydrogen-enriched stream ( 51 ) and a waste gas ( 52 ), wherein the waste gas ( 52 ) is recycled upstream of the carbon dioxide PSA unit ( 30 ).