Method of recovering a hydrogen-enriched product and CO2 in a hydrogen production unit

A process for producing a hydrogen-enriched gas stream comprising:

• processing a feed stream comprising hydrocarbons or a carbonaceous feedstock in a hydrogen production process unit to produce a synthesis gas mixture comprising hydrogen, carbon monoxide, methane, water, and an inert gas;
• performing a water-gas-shift process on the synthesis gas mixture to form shifted synthesis gas comprising carbon dioxide;
• performing a hydrogen pressure swing adsorption (PSA) separation process and a carbon dioxide separation process on the shifted synthesis gas to form a high-pressure hydrogen product stream comprising the hydrogen, an inert gas-enriched off gas stream from the hydrogen separation process comprising the inert gas and depleted of carbon-containing components, a carbon dioxide product stream comprising carbon dioxide, and a carbon-enriched off gas stream comprising the carbon monoxide and the methane, the hydrogen PSA process comprising a three-product PSA unit;
• introducing the carbon-enriched off gas stream into a membrane separation unit to form a permeate stream enriched in hydrogen and a residue stream enriched in carbon monoxide and methane;
• and
• recycling the residue stream to the hydrogen production process unit;
• wherein the carbon dioxide recovery system comprises an amine separation unit,
• or a cryogenic separation unit, or a carbon dioxide PSA unit, or combinations thereof;
• and
• wherein performing the hydrogen PSA separation process and the carbon dioxide separation process comprises:
• introducing the shifted synthesis gas into the three-product PSA unit to form the high-pressure hydrogen product stream, the inert gas-enriched off gas stream, and a hydrogen depleted tail gas stream;
• and
• introducing the hydrogen depleted tail gas stream into a carbon dioxide recovery system to form the carbon dioxide product stream and the carbon-enriched off gas stream;
• or
• introducing the shifted synthesis gas into the carbon dioxide recovery system to form the carbon dioxide product stream and a carbon dioxide-depleted stream;
• and
• introducing the carbon dioxide-depleted stream into the three product PSA unit to form the high-pressure hydrogen stream, the inert-enriched off gas stream, and the carbon-enriched off gas stream.