Integration of carbon monoxide preferrential oxidation with a blue hydrogen plant

A method for producing hydrogen, comprising:

• i. reforming a hydrocarbon gas mixture stream with steam and optionally an oxygen-rich gas in a reformer to produce a syngas stream,
• ii. recovering thermal energy of the syngas stream in a process heat recovery unit downstream of the reformer, thereby cooling the syngas stream,
• iii. converting carbon-monoxide of a cooled syngas to carbon-dioxide and hydrogen by subjecting it to one or more water-gas-shift-units to provide a hydrogen-enriched shifted syngas,
• iv. recovering thermal energy of the hydrogen-enriched shifted syngas thereby cooling the hydrogen-enriched shifted syngas and separating condensed water therefrom,
• v. separating the hydrogen-enriched shifted syngas by subjecting it to a hydrogen pressure swing adsorption (H2 PSA) process thereby forming a hydrogen product stream and a lower-pressure tail gas stream,
• vi. introducing at least a portion of the lower-pressure tail gas stream and an oxygen-containing gas to a CO preferential oxidation catalyst unit to provide a carbon-dioxide-enriched tail gas stream therefrom, and
• vii. passing the carbon-dioxide-enriched tail gas stream to a carbon-dioxide separation unit to provide a carbon-dioxide product stream and a carbon-dioxide depleted gas stream, wherein the carbon-dioxide product stream is sent to a sequestration process and at least a portion of the carbon-dioxide depleted gas stream is recycled to the process as a feedstock and/or a fuel.