Patent ID: 6045602
Filing Date: 2000-04-04
Classification: C21B,F25J,Y02C,Y02P

Abstract:
A method for integrating a blast furnace and a direct reduction reactor using cryogenic rectification comprising:(A) separating air in a cryogenic air separation plant by cryogenic rectification to produce oxygen;(B) mixing oxygen from the cryogenic air separation plant with air to form blast air comprising from about 22 to 50 mole percent oxygen with the remainder comprised primarily of nitrogen;(C) passing the blast air into a blast furnace and combusting oxygen of the blast air with hydrocarbon fuel in the blast furnace to produce blast furnace gas comprising nitrogen, carbon monoxide and hydrogen;(D) reacting the carbon monoxide with steam to produce carbon dioxide and additional hydrogen, and removing the carbon dioxide from the blast furnace gas to produce fortified blast furnace gas comprising nitrogen and hydrogen;(E) passing the fortified blast furnace gas into a cryogenic rectification plant and separating the fortified blast furnace gas within the cryogenic rectification plant to produce hydrogen and residual nitrogen; and(F) reacting hydrogen from the cryogenic rectification plant with iron ore in a direct reduction reactor to produce iron.