The present invention is
natural gas steam reforming apparatus for generating an output gas mixture of
carbon dioxide and
hydrogen. The apparatus is made from two enclosures. A first
enclosure contains a source of water,
superheated steam, and channels, located within a lower portion of the first
enclosure, which contain a water-gas-shift catalyst for converting CO into CO2 and H2. The heat from hot gas flowing through the channels is released into the first
enclosure to boil the water to generate the
superheated steam. A second enclosure, contained within an upper portion of the first enclosure, includes a steam inlet for receiving the
superheated steam from the first enclosure; a
combustion chamber; and a reformation chamber. The
combustion chamber is used for combusting a portion of the
natural gas to generate additional steam, heat, and a hot gas mixture of CO2, CO, and H2. The reformation chamber is used for
steam reforming a remaining portion of the
natural gas to generate additional hot gas mixture of CO2, CO, and H2. The hot gas mixture is directed through the channels installed in the first enclosure in which the water-gas-shift catalyst converts residual CO into additional CO2 and additional H2, to produce an output gas mixture of
carbon dioxide and
hydrogen. In the present invention, the first and second enclosures function as a top-to-bottom linear countercurrent
heat exchanger. In one embodiment of the present invention, an external third enclosure containing a
combustion chamber and a boiler for combusting natural gas with
ambient air may be used to boil additional water into superheated steam which is then fed into the first enclosure.