Thermally-integrated low temperature water-gas shift reactor apparatus and process

A thermally-integrated water-gas shift reactor for reducing the concentration of carbon monoxide contained in a hydrogen-rich reformate gas, according to the water-gas shift reaction, said reactor comprising:

• an inner generally cylindrical vessel containing a volume of boiling water, said inner generally cylindrical vessel defining a waste-heat recovery steam generator for recovering reaction heat generated by the water-gas shift reaction to produce steam from the boiling water;
• an outer generally cylindrical vessel disposed concentrically about the inner generally cylindrical vessel to define an annular space therebetween, said outer generally cylindrical vessel having an outer surface that is exposed to the atmosphere;
• a helical coil inserted within the annular space, said helical coil being welded to both the outer surface of the inner generally cylindrical vessel and the inner surface of the outer generally cylindrical vessel;
• a reaction zone defined by the space confined between the helical coil, the outer surface of the inner generally cylindrical vessel, and the inner surface of the outer generally cylindrical vessel, said reaction zone being filled with a water-gas shift catalyst for catalyzing the water-gas shift reaction;
• an inlet for supplying reformate gas to the reaction zone;
• and
• an outlet for discharging reformate gas, with a reduced concentration of carbon monoxide, from the reaction zone;
• wherein the reformate gas that is supplied to the reaction zone is directed through the catalyst in a helical manner, around the waste-heat recovery steam generator;
• and
• wherein the helical coil functions as an extended heat transfer surface to enhance the rate of heat transfer between the reaction zone and the waste-heat recovery steam generator.