Device and methods of ammonia generation for NOx abatement

1. An ammonia generator, comprising:

a shell; and

a catalyst bed housed within said shell; wherein said catalyst bed comprises a substrate and a catalyst,

wherein said catalyst comprises a catalytic metal capable of reacting NOx and hydrogen to form ammonia, and a material capable of adsorbing NOx;

wherein said catalytic metal comprises about 100 g/ft 3 to about 260 g/ft 3 ruthenium, and about 10 g/ft 3 to about 50 g/ft 3 to platinum.

2. The generator of claim 1 , wherein said catalytic metal further comprises less than or equal to about 5 g/ft 3 rhodium and less than or equal to about 5 g/ft 3 palladium.

3. The generator of claim 1 , wherein said catalytic metal comprises no added rhodium and no added palladium.

4. The generator of claim 1 , wherein said ammonia generator is capable of converting about 20 vol % to about 75 vol % of NOx to ammonia, based upon a total volume of NOx in an exhaust stream.

5. The generator of claim 4 , wherein said ammonia generator is capable of converting about 30 vol % to about 65 vol % of NOx to ammonia, based upon a total volume of NOx in an exhaust stream.

6. The generator of claim 5 , wherein said ammonia generator is capable of converting about 40 vol % to about 55 vol % of NOx to ammonia, based upon a total volume of NOx in an exhaust stream.

7. The generator of claim 1 , wherein said material comprises neodymium.

8. A NOx abatement system, comprising:

an ammonia generator comprising an inlet end and an outlet end

an exhaust conduit connected in fluid communication to said inlet end;

a mixture conduit connected in fluid communication to said outlet end;

a by-pass circuit connected in fluid communication to said exhaust conduit on a first end and connected in fluid communication to said mixture conduit on a second end;

a reformer connected to said mixture conduit; and,

a valve capable of directing and inhibiting a flow of fluids, wherein said valve is disposed in said mixture conduit at a position capable of inhibiting flow of a fluid stream from said by-pass circuit into said ammonia generator and capable of directing reformate from said reformer into said ammonia generator.

9. The NOx abatement system of claim 8 , further comprising a selective catalytic reduction catalyst connected to said mixture conduit downstream from said by-pass conduit.

10. The NOx abatement system of claim 8 , wherein said ammonia generator comprises

a shell; and

a catalyst bed housed within said shell; wherein said catalyst bed comprises a substrate and a catalyst,

wherein said catalyst comprises a catalytic metal capable of reacting NOx and hydrogen to form ammonia, and a material capable of adsorbing NOx;

wherein said catalytic metal comprises about 100 g/ft 3 to about 260 g/ft 3 ruthenium, and about 10 g/ft 3 to about 50 g/ft 3 to platinum.

11. The NOx abatement system of claim 10 , wherein said catalytic metal further comprises less than or equal to about 5 g/ft 3 rhodium and less than or equal to about 5 g/ft 3 palladium.

12. The NOx abatement system of claim 11 , wherein said catalytic metal comprises no added rhodium and no added palladium.

13. A method of operating a NOx abatement system, comprising:

introducing an exhaust stream to an ammonia generator in a normal flow direction;

adsorbing NOx from said exhaust stream in said ammonia generator;

diverting said exhaust stream around said ammonia generator;

introducing hydrogen to said ammonia generator in a direction opposite said normal flow direction; and

generating ammonia within said ammonia generator.

14. The method of claim 13 , further comprising ceasing said diversion of said exhaust stream and introducing said ammonia to a selective catalytic reduction catalyst.

15. The method of claim 13 , further comprising converting about 20 vol % to about 75 vol % of said NOx to said ammonia, based upon a total volume of NOx in said exhaust stream.

16. The method of claim 15 , comprising converting about 30 vol % to about 65 vol % of said NOx.

17. The method of claim 16 , comprising converting about 40 vol % to about 55 vol % of said NOx.

18. The method of claim 13 , further comprising forming said hydrogen in a reformer.

19. The method of claim 13 , wherein said ammonia generator comprises

a shell; and

a catalyst bed housed within said shell; wherein said catalyst bed comprises a substrate and a catalyst,

wherein said catalyst comprises a catalytic metal capable of reacting NOx and hydrogen to form ammonia, and a material capable of adsorbing NOx;

wherein said catalytic metal comprises about 100 g/ft 3 to about 260 g/ft 3 ruthenium, and about 10 g/ft 3 to about 50 g/ft 3 to platinum.

20. The method of claim 19 , wherein said catalytic metal further comprises less than or equal to about 5 g/ft 3 rhodium and less than or equal to about 5 g/ft 3 palladium.