摘要 |
1438120 Gas purification EXXON RESEARCH & ENG CO 1 Aug 1973 [1 Sept 1972] 36530/73 Heading C1A Nitrogen oxides may be removed from a gas stream by adding ammonia to the stream to provide at least 0À5 mole of ammonia per mole of NO x and contacting the resultant stream under oxidizing conditions and at a gas inlet temperature of from 600‹ to 950‹ F. with a solid contact mass comprising at least one non-noble transition metal or compound thereof disposed on a refractory porous carrier having a surface area of at least 40 m.<SP>2</SP>/gram. The contact-mass may comprise copper or ferric oxide, supported on alumina, silica or alumina-silica. Other transition metal oxides which may be used include oxides of vanadium, chromium, molybdenum, tungsten, manganese, cobalt and nickel. The contact mass may be regnerated by treating with air or flue gas containing more than the usual amount of oxygen, or by reduction with hydrogen, carbon monoxide, methane, ethane, propane, butane, hexane or decane, mixed if desired with steam. |