US2013098279A1PendingUtilityA1

Combustion Apparatus And Applications Thereof

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Assignee: BERTOLE CHRISTOPHERPriority: Jul 27, 2011Filed: Jul 27, 2012Published: Apr 25, 2013
Est. expiryJul 27, 2031(~5 yrs left)· nominal 20-yr term from priority
Inventors:Christopher J. BertoleJeremy Thomas FreemanChris E. Difrancesco
Y02C20/10F23J 15/02B01D 53/8631F23C 6/045F23C 2900/06041F23J 2219/10F23J 2215/10
38
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Claims

Abstract

In one aspect, combustion apparatus are described herein which, in some embodiments, can provide advantageous NO x loads while mitigating the formation of SCR catalyst deactivation species in the flue gas stream. In some embodiments, a combustion apparatus described herein comprises a furnace providing a flue gas stream, the furnace comprising a primary combustion zone having an air to fuel stoichiometric ratio ranging from 0.89 to 1.05 and air staging apparatus associated with the furnace.

Claims

exact text as granted — not AI-modified
That which is claimed is: 
     
         1 . A combustion apparatus comprising:
 a furnace providing a flue gas stream, the furnace comprising a primary combustion zone having an air to fuel stoichiometric ratio ranging from 0.89 to 1.05 and an air staging apparatus; and   a catalytic reactor for receiving the flue gas stream from the furnace, the catalytic reactor comprising catalyst for the selective catalytic reduction (SCR) of nitrogen oxides in the flue gas stream.   
     
     
         2 . The combustion apparatus of  claim 1 , wherein the air to fuel stoichiometric ratio ranges from 0.90 to 0.99. 
     
     
         3 . The combustion apparatus of  claim 1 , wherein the air to fuel stoichiometric ratio ranges from 0.92 to 0.94. 
     
     
         4 . The combustion apparatus of  claim 1 , wherein the air to fuel stoichiometric ratio ranges from 0.96 to 0.99. 
     
     
         5 . The combustion apparatus of  claim 1 , wherein the air to fuel stoichiometric ratio ranges from 0.93 to 0.97. 
     
     
         6 . The combustion apparatus of  claim 1 , wherein the air to fuel stoichiometric ratio ranges from 0.93 to 0.95. 
     
     
         7 . The combustion apparatus of  claim 1 , wherein the SCR catalyst comprises monolithic structural catalyst bodies. 
     
     
         8 . The combustion apparatus of  claim 7 , wherein one or more of the structural catalyst bodies satisfies the equation y=(K/K o ), wherein K is the catalytic activity of the structural catalyst body after 16,000 hours of operation in the catalytic reactor, K o  is the initial catalytic activity of the structural catalyst body and y ranges from about 0.6 to about 0.9. 
     
     
         9 . The combustion apparatus of  claim 8 , wherein y ranges from about 0.65 to 0.85. 
     
     
         10 . The combustion apparatus of  claim 8 , wherein y ranges from about 0.70 to about 0.80. 
     
     
         11 . The combustion apparatus of  claim 1 , wherein the flue gas stream provided to the catalytic reactor by the furnace comprises a reduced amount of at least one SCR catalyst deactivation species in comparison to a reference flue gas stream provided from the furnace wherein the primary combustion zone has an air to fuel stoichiometric ratio outside of 0.89 to 1.05. 
     
     
         12 . The combustion apparatus of  claim 1 , wherein the flue gas provided to the catalytic reactor by the furnace comprises a reduced amount of at least one SCR catalyst deactivation species in comparison to a reference flue gas stream provided from the furnace wherein the primary combustion zone has an air to fuel stoichiometric ratio outside of 0.90 to 0.99. 
     
     
         13 . The combustion apparatus of  claim 11 , wherein the at least one catalyst deactivation species is selected from the group consisting of P 2 O 5 , H 3 PO 4 , CaO, CaSO 4 , SiO 2  and mixtures thereof. 
     
     
         14 . The combustion apparatus of  claim 13 , wherein the flue gas provided to the catalytic reactor comprises the at least one catalyst deactivation species in an amount at least 10 volume percent less than the reference flue gas stream. 
     
     
         15 . The combustion apparatus of  claim 13 , wherein the flue gas provided to the catalytic reactor comprises the at least one catalyst deactivation species in an amount at least 20 volume percent less than the reference flue gas stream. 
     
     
         16 . The combustion apparatus of  claim 1 , wherein the flue gas stream provided to the catalytic reactor has a nitrogen oxide load up to about 90% of a nitrogen oxide load of a reference flue gas stream produced by a substantially identical furnace, operating under substantially identical conditions not employing the air staging apparatus. 
     
     
         17 . The combustion apparatus of  claim 1 , wherein the fuel comprises subbituminous coal. 
     
     
         18 . The combustion apparatus of  claim 17 , wherein the subbituminous coal comprises powder river basin (PRB) coal. 
     
     
         19 . The combustion apparatus of  claim 1 , wherein the fuel comprises lignite. 
     
     
         20 . A method of decreasing deactivation of selective catalytic reduction (SCR) catalyst comprising:
 reducing an amount of at least one catalytic deactivation species for the SCR catalyst in a flue gas stream from a furnace of a combustion apparatus comprising air staging apparatus, wherein reducing the amount of the catalytic deactivation species comprises providing an air to fuel stoichiometric ratio ranging from 0.89 to 1.05 in a primary combustion zone of the furnace.   
     
     
         21 . The method of  claim 20 , wherein the at least one catalytic deactivation species physically deactivates the SCR catalyst. 
     
     
         22 . The method of  claim 20 , wherein the at least one catalytic deactivation species chemically deactivates the SCR catalyst. 
     
     
         23 . The method of  claim 20 , wherein the at least one catalytic deactivation species is selected from the group consisting of P 2 O 5 , H 3 PO 4 , CaO, CaSO 4 , SiO 2  and mixtures thereof. 
     
     
         24 . The method of  claim 20 , wherein the at least one catalytic deactivation species is H 3 PO 4 . 
     
     
         25 . The method of  claim 20 , wherein the air to fuel stoichiometric ratio ranges from 0.90 to 0.99. 
     
     
         26 . The method of  claim 20 , wherein the air to fuel stoichiometric ratio ranges from 0.93 to 0.97. 
     
     
         27 . The method of  claim 20 , wherein the flue gas stream comprises the catalytic deactivation species in an amount at least 10 volume percent less than a reference flue gas stream provided from the furnace wherein the primary combustion zone of the furnace has an air to fuel stoichiometric ratio outside of 0.89 to 1.05. 
     
     
         28 . The method of  claim 20 , wherein the flue gas stream comprises the catalytic deactivation species in an amount at least 10 volume percent less than a reference flue gas stream provided from the furnace wherein the primary combustion zone of the furnace has an air to fuel stoichiometric ratio outside of 0.93 to 0.97. 
     
     
         29 . The method of  claim 20 , wherein the flue gas stream has a nitrogen oxide load up to about 90% of a nitrogen oxide load of a reference flue gas stream produced by a substantially identical furnace operating under substantially identical conditions not employing the air staging apparatus. 
     
     
         30 . The method of  claim 20 , wherein the SCR catalyst comprises monolithic structural catalyst bodies. 
     
     
         31 . The method of  claim 30 , wherein the reduction of the at least one catalytic deactivation species substantially results in one or more of the monolithic structural catalyst bodies satisfying the equation y=(K/K o ), wherein K is the catalytic activity of the structural catalyst body after 16,000 hours of operation in the catalytic reactor, K o  is the initial catalytic activity of the structural catalyst body and y ranges from about 0.6 to about 0.9. 
     
     
         32 . The method of  claim 31 , wherein y ranges from about 0.65 to 0.85. 
     
     
         33 . The method of  claim 31 , wherein y ranges from about 0.70 to about 0.80. 
     
     
         34 . The method of  claim 20 , wherein the fuel comprises a subbituminous coal. 
     
     
         35 . The method of  claim 34 , wherein the subbituminous coal comprises Powder River Basin (PRB) coal. 
     
     
         36 . The method of  claim 20 , wherein the fuel comprises lignite.

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