Patent ID: 7985399

Claim:
A method of producing a hydrogen product from a synthesis gas stream formed by gasifying a carbonaceous feedstock, said method comprising: preheating a feed stream comprising the synthesis gas stream and introducing the feed gas stream into a first shift conversion unit to form a first shifted gas stream; cooling the first shifted gas stream and introducing the first shifted gas stream into an acid gas removal unit to remove carbon dioxide and sulfur from the first shifted gas stream and thereby form a purified first shifted gas stream; separating part of the hydrogen product from the purified first shifted gas stream in a first pressure swing adsorption unit, thereby to also produce a first tail gas stream; heating a combined reactant stream in a steam methane reforming system and subjecting the combined reactant stream to steam methane reforming to produce a reformed stream, the combined reactant stream formed by combining steam with at least part of the first tail gas stream and a hydrocarbon containing stream, after having been preheated, the hydrocarbon containing stream and steam being combined at a flow rate such that methanation is at least prevented within the steam methane reformer; cooling the reformed stream and introducing the reformed stream into a second shift conversion unit to produce a second shifted gas stream from the reformed stream; and cooling the second shifted gas stream and separating a remaining part of the hydrogen product therefrom in a second pressure swing adsorption unit, thereby to also produce a second tail gas stream.