US 7,591,987 B1
Method and apparatus for treating ammonia-containing gas
Yasuyoshi Kato, Kure (Japan)
Assigned to Babcock-Hitachi Kabushiki Kaisha, Tokyo (Japan)
Appl. No. 10/579,368
PCT Filed Nov. 12, 2004, PCT No. PCT/JP2004/016868
§ 371(c)(1), (2), (4) Date Jan. 17, 2007,
PCT Pub. No. WO2005/046844, PCT Pub. Date May 26, 2005.
Claims priority of application No. 2003-385245 (JP), filed on Nov. 14, 2003.
Int. Cl. B01D 53/54 (2006.01); B01D 53/56 (2006.01); B01D 53/58 (2006.01); B01D 53/74 (2006.01); B01D 53/86 (2006.01)
U.S. Cl. 423—237  [423/239.1; 423/239.2; 422/168; 422/169; 422/170; 422/171; 422/177; 422/180; 422/181] 9 Claims
 
1. In a method for treating an NH3-containing gas wherein a gas containing an ammonia (NH3) of a high concentration is allowed to pass through a pre-treatment catalyst layer having a function for oxidizing NH3 to generate nitrogen monoxide (NO), and then pass through a denitration catalyst layer having in combination, a denitration function and a function for oxidizing NH3 to generate NO, which contains titanium oxide (TiO2); an oxide of at least one selected from the group consisting of vanadium (V), tungsten (W), molybdenum (Mo), zeolite, titania, alumina, and zirconia supported with platinum (Pt), and combinations thereof; a method for preventing thermal deterioration of the catalyst of the denitration catalyst layer, characterized by disposing a catalyst layer not having the function for oxidizing NH3 to generate NO in the pre-treatment catalyst layer in parallel thereto.