Vanadium/Titania Catalyst Comprising Natural Manganese Ore for Removing Nitrogen Oxides and Dioxin in Wide Operating Temperature Range and Method of Using the Same

Abstract

Disclosed is a vanadium/titania-based catalyst including natural manganese ore for removing nitrogen oxides and dioxin in a wide operating temperature range and a method of using the same. Specifically, this invention pertains to a vanadium/titania (V/TiO2)-based catalyst including natural manganese ore for removing nitrogen oxides and dioxin in a wide operating temperature range, in which the WTiO2 catalyst for selective catalytic reduction of nitrogen oxides and removal of dioxin contained in flue gas includes 5-30 wt % of natural manganese ore, thus exhibiting excellent activity of removing nitrogen oxides even in the low temperature range and of removing dioxin at the same time, and to a method of using the same. The catalyst of this invention has good thermal stability and thus can simultaneously manifest nitrogen oxides removal performance and dioxin removal performance superior to conventional vanadium/titania catalysts in a wide temperature range (150˜450° C.) including not only a high temperature range but also a low temperature range. As well, since unreacted ammonia emissions can be reduced, the formation of an ammonium salt is prevented and ammonium nitrate is decomposed at low temperatures, thus solving the problems of inactivation of the catalyst due to catalytic poisoning and of a shortened lifetime thereof, leading to economic benefits.

1 . A vanadium/titania (V/TiO 2 )-based catalyst comprising natural manganese ore for removing nitrogen oxides and dioxin in a wide operating temperature range, wherein the vanadium/titania-based catalyst, suitable for use in selective catalytic reduction of nitrogen oxides and removal of dioxin contained in flue gas, comprises 0.5˜10 wt % of vanadium. 
   
   
       2 . The vanadium/titania-based catalyst according to  claim 1 , which further comprises 0˜15 wt % of tungsten oxides based on the weight of titania. 
   
   
       3 . The vanadium/titania-based catalyst according to  claim 1 , wherein a precursor of the vanadium is ammonium metavanadate or vanadium chloride. 
   
   
       4 . The vanadium/titania-based catalyst according to  claim 1 , wherein the natural manganese ore is pyrolusite, composed of β-MnO 2 . 
   
   
       5 . (canceled) 
   
   
       6 . The vanadium/titania-based catalyst according to  claim 1 , which is applied to a structure selected from the group consisting of a metal plate, a metal fiber, a ceramic filter, and a honeycombed structure. 
   
   
       7 . The vanadium/titania-based catalyst according to  claim 1 , which is applied to an air preheater, or a tube group, a duct, and/or a wall of a boiler. 
   
   
       8 . A method of selective catalytic reduction of nitrogen oxides and removal of dioxin, contained in flue gas, which is conducted at 150˜450° C. at a gas hourly space velocity of 1000˜60000 hr −1  in the presence of the catalyst of  claim 1 . 
   
   
       9 . The method according to  claim 8 , wherein ammonia, which is a reducing agent, is supplied at a molar ratio of NH 3 /NO x  of 0.6˜1.2 upon the selective catalytic reduction of the nitrogen oxides. 
   
   
       10 . The method according to  claim 8 , wherein the flue gas comprises 0˜500 ppm dioxin present therein upon the selective catalytic reduction of the nitrogen oxides. 
   
   
       11 . The vanadium/titania-based catalyst according to  claim 2 , which is applied to a structure selected from the group consisting of a metal plate, a metal fiber, a ceramic filter, and a honeycombed structure. 
   
   
       12 . The vanadium/titania-based catalyst according to  claim 3 , which is applied to a structure selected from the group consisting of a metal plate, a metal fiber, a ceramic filter, and a honeycombed structure. 
   
   
       13 . The vanadium/titania-based catalyst according to  claim 4 , which is applied to a structure selected from the group consisting of a metal plate, a metal fiber, a ceramic filter, and a honeycombed structure. 
   
   
       14 . The vanadium/titania-based catalyst according to  claim 2 , which is applied to an air preheater, or a tube group, a duct, and/or a wall of a boiler. 
   
   
       15 . The vanadium/titania-based catalyst according to  claim 3  which is applied to an air preheater, or a tube group, a duct, and/or a wall of a boiler. 
   
   
       16 . The vanadium/titania-based catalyst according to  claim 4 , which is applied to an air preheater, or a tube group, a duct, and/or a wall of a boiler. 
   
   
       17 . The method of selective catalytic reduction of nitrogen oxides and removal of dioxin contained in flue gas, which is conducted at 150˜450° C. at a gas hourly space velocity of 1000˜60000 hr −1  in the presence of the catalyst of  claim 2 . 
   
   
       18 . The method of selective catalytic reduction of nitrogen oxides and removal of dioxin contained in flue gas, which is conducted at 150˜450° C. at a gas hourly space velocity of 1000˜60000 hr −1  in the presence of the catalyst of  claim 3 . 
   
   
       19 . The method of selective catalytic reduction of nitrogen oxides and removal of dioxin contained in flue gas, which is conducted at 150˜450° C. at a gas hourly space velocity of 1000˜60000 hr −1  in the presence of the catalyst of  claim 4 .