Method of regeneration of scr catalyst poisoned by phosphorous components in flue gas

Abstract

A method of regeneration of a SCR catalyst for use in high temperature thermal processes such as in a power plant facility burning fossil fuels, bio-based fuels, or a combination thereof, wherein the catalyst is poisoned by phosphorous components in the flue gas and the catalyst is treated using a base, preferably an alkali metal hydroxide.

1 . A method for regenerating a phosphorous-poisoned SCR catalyst comprising:
 removing phosphorous contaminants from a phosphorous-poisoned SCR catalyst to provide a regenerated SCR catalyst having from about 85% to about 90% of an original catalytic activity.   
     
     
         2 . The method of  claim 1 , wherein the phosphorous-poisoned SCR catalyst comprises about 0.3 weight percent or more of phosphorous as measured as P 2 O 5 . 
     
     
         3 . The method of  claim 1 , wherein the regenerated SCR catalyst comprises less than 0.3 weight percent of phosphorous as measured as P 2 O 5 . 
     
     
         4 . The method of  claim 3 , wherein the regenerated SCR catalyst comprises less than 0.2 weight percent of phosphorous as measured as P 2 O 5 . 
     
     
         5 . The method of  claim 1 , wherein removing the phosphorous contaminants comprises solubilizing the phosphorous contaminants in an aqueous solution. 
     
     
         6 . The method of  claim 5 , wherein the aqueous solution is an aqueous solution of an alkali metal hydroxide at a pH above 8.5. 
     
     
         7 . The method of  claim 6 , wherein the alkali metal hydroxide is sodium hydroxide, potassium hydroxide, or a combination thereof. 
     
     
         8 . The method of  claim 1 , wherein the phosphorous-poisoned SCR catalyst is from a power plant that burns fuel selected from fossil-fuel, bio-based fuel, or a combination thereof. 
     
     
         9 . The method of  claim 8 , wherein the fossil-fuel is sub-bituminous Powder River Basis coal or high phosphorous coal. 
     
     
         10 . The method of  claim 8 , wherein the bio-based fuel comprises biomass, bio-residue, and combinations thereof. 
     
     
         11 . The method of  claim 1 , wherein removing phosphorous contaminants comprises reducing the phosphorous on the catalyst by about 66% to about 72% by weight. 
     
     
         12 . A regenerated SCR catalyst regenerated from a phosphorous-poisoned SCR catalyst, by a process comprising:
 removing phosphorous contaminants from a phosphorous-poisoned SCR catalyst to provide a regenerated SCR catalyst having from about 85% to about 90% of an original catalytic activity.   
     
     
         13 . The regenerated SCR catalyst of  claim 12 , wherein the phosphorous-poisoned SCR catalyst comprises about 0.3 weight percent or more of phosphorous as measured as P 2 O 5 . 
     
     
         14 . The regenerated SCR catalyst of  claim 12 , wherein the regenerated SCR catalyst comprises less than 0.3 weight percent of phosphorous as measured as P 2 O 5 . 
     
     
         15 . The regenerated SCR catalyst of  claim 12 , wherein the regenerated SCR catalyst comprises less than 0.2 weight percent of phosphorous as measured as P 2 O 5 . 
     
     
         16 . The regenerated SCR catalyst of  claim 12 , wherein the phosphorous-poisoned SCR catalyst is from a power plant that burns fuel selected from fossil-fuel, bio-based fuel, or a combination thereof. 
     
     
         17 . The regenerated SCR catalyst of  claim 12 , wherein removing the phosphorous contaminants comprises solubilizing the phosphorous contaminants in an aqueous solution. 
     
     
         18 . The regenerated SCR catalyst of  claim 17 , wherein the aqueous solution is an aqueous solution of an alkali metal hydroxide at a pH above 8.5.