Patent ID: 8137422

Claim:
A process for producing a hydrogen-containing product gas, comprising: (a) introducing a process stream comprising steam and at least one hydrocarbon selected from the group consisting of methane, ethane, propane, butane, pentane, and hexane into a plurality of catalyst-containing reformer tubes in a reformer furnace and reacting the process stream inside the plurality of catalyst-containing reformer tubes at a first temperature ranging from 700° C. to 1000° C. and a first pressure ranging from 2 to 50 atmospheres to form a reformate stream comprising hydrogen, carbon monoxide, methane and steam and withdrawing the reformate stream from the plurality of catalyst-containing reformer tubes; (b) reacting the reformate stream in the presence of a shift catalyst at a second temperature ranging from 190° C. to 500° C. and a second pressure ranging from 2 to 50 atmospheres to form a second process stream comprising carbon dioxide, hydrogen, carbon monoxide and methane; (c) scrubbing the second process stream with a wash stream to form a carbon dioxide-depleted stream and a carbon dioxide-loaded wash stream; (d) separating the carbon dioxide-depleted stream to form the hydrogen-containing product gas and a by-product gas comprising methane and carbon monoxide; (e) introducing a portion of the by-product gas into the process stream at a location upstream of the plurality of catalyst-containing reformer tubes and/or into the reformate stream at a location upstream of a reforming catalyst in a secondary reforming reactor; and (f) combusting a fuel gas comprising a portion of the hydrogen-containing product gas, optionally a portion of the by-product gas, and optionally a supplementary fuel in the reformer furnace external to the plurality of catalyst-containing reformer tubes to supply energy for reacting the process stream inside the plurality of catalyst-containing reformer tubes, and withdrawing a flue gas from the reformer furnace.