Patent ID: 6190632
Filing Date: 2001-02-20
Classification: C01B,C21B,F25J,Y02C,Y02P

Abstract:
A method for producing ammonia employing 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 in the blast furnace to produce blast furnace gas comprising nitrogen, carbon monoxide and hydrogen;(D) passing said blast furnace gas from said blast furnace to a shift reaction section wherein the carbon monoxide is reacted with steam to produce carbon dioxide and additional hydrogen, and then passing the carbon dioxide onto or into material to remove 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 ammonia synthesis gas comprising hydrogen and nitrogen in about a 3 to 1 ratio and residual nitrogen;(F) passing ammonia synthesis gas from the cryogenic rectification plant to an ammonia production plant and reacting hydrogen and nitrogen of the ammonia synthesis gas within the ammonia production plant to produce ammonia; and(G) passing residual nitrogen from the cryogenic rectification plant in contact with said material and passing the carbon dioxide from said material into the residual nitrogen.