US Patent 8137422 Steam-hydrocarbon reforming with reduced carbon dioxide emissions

A process for producing a hydrogen-containing product gas with reduced carbon dioxide emissions compared to conventional hydrogen production processes. A hydrocarbon and steam are reformed in a reformer and the resulting reformate stream is shifted in one or more shift reactors. The shifted mixture is scrubbed to remove carbon dioxide to form a carbon dioxide-depleted stream. The carbon dioxide-depleted stream is separated to form a hydrogen-containing product gas and a by-product gas. A portion of the hydrogen containing product gas is used as a fuel in the reformer and a portion of the by-product gas is recycled back into the process. The process may optionally include reforming in a prereformer and/or an oxygen secondary reformer.