NOx adsorber aftertreatment system for internal combustion engines
The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes a parallel arrangement of an adsorber catalyst and a bypass. The exhaust flow from the engine is routed through the adsorber during lean operation. At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that contains the adsorber catalyst to be regenerated (e.g., 20% through the catalyst leg, 80% of the flow to the bypass leg). A quantity of hydrocarbon is injected into the reduced-flow catalyst leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst. Once the leg has been regenerated, the exhaust flow is switched to flow 100% through the adsorber leg.
1. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a sulfur trap having a sulfur trap input operatively coupled to the engine exhaust and having a sulfur trap output;
a catalytic soot filter having a soot filter input operatively coupled to the sulfur trap output and having a soot filter output;
a valve system having a valve input operatively coupled to the soot filter output, a first valve output and having a second valve output;
an NOx adsorber having an adsorber input operatively coupled to the first valve output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output operatively coupled to the adsorber output; and
a diesel oxidation catalyst having a DOC input operatively coupled to the adsorber output and to the bypass output and having a DOC output.
2. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a valve system having a valve input operatively coupled to the engine exhaust, a first valve output and having a second valve output;
an adsorber having an adsorber input operatively coupled to the first valve output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output operatively coupled to the adsorber output;
a sulfur trap having a sulfur trap input operatively coupled to the engine exhaust and having a sulfur trap output operatively coupled to the valve system input; and
a catalytic soot filter having a soot filter input operatively coupled to the sulfur trap output and having a soot filter output operatively coupled to the valve system input.
3. The system of claim 2 , further comprising:
a diesel oxidation catalyst having a DOC input operatively coupled to the adsorber output and to the bypass output and having a DOC output.
4. The system of claim 2 , further comprising:
a temperature and lamda sensor having a sensor input operatively coupled to the valve system input.
5. The system of claim 2 , further comprising:
an NOx sensor having an NOx sensor input operatively coupled to the adsorber output.
6. The system of claim 2 , wherein the valve system comprises a proportional control 3-way valve.
7. The system of claim 2 , further comprising:
a supply of fuel;
a pump having a pump inlet operatively coupled to the supply of fuel and having a pump outlet;
a fuel injector having an injector input operatively coupled to the pump outlet and having an injector output operatively coupled to the adsorber input.
8. The system of claim 7 , further comprising:
an igniter operatively coupled to the adsorber input.
9. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a valve system having a valve input operatively coupled to the engine exhaust a first valve output and having a second valve output;
a catalytic soot filter having a soot filter input operatively coupled to the valve system output and having a soot filter output;
an adsorber having an adsorber input operatively coupled to the soot filter output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output operatively coupled to the adsorber output; and
a sulfur trap having a sulfur trap input operatively coupled to the engine exhaust and having a sulfur trap output operatively coupled to the valve system input.
10. The system of claim 9 , further comprising:
a diesel oxidation catalyst having a DOC input operatively coupled to the adsorber output and to the bypass output and having a DOC output.
11. The system of claim 9 , further comprising:
an NOx sensor having an NOx sensor input operatively coupled to the adsorber output.
12. The system of claim 9 , wherein the valve system comprises a proportional control 3-way valve.
13. The system of claim 9 , further comprising:
a supply of fuel;
a pump having a pump inlet operatively coupled to the supply of fuel and having a pump outlet;
a fuel injector having an injector input operatively coupled to the pump outlet and having an injector output operatively coupled to the soot filter input.
14. The system of claim 13 , further comprising:
an igniter operatively coupled to the soot filter input.
15. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a valve system having a valve input operatively coupled to the engine exhaust, a first valve output and having a second valve output;
a catalytic soot filter having a soot filter input operatively coupled to the valve system output and having a soot filter output;
an adsorber having an adsorber input operatively coupled to the soot filter output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output operatively coupled to the adsorber output; and
a temperature and lamda sensor having a sensor input operatively coupled to the valve system input.
16. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a valve system having a valve input operatively coupled to the engine exhaust, a first valve output and having a second valve output;
an adsorber having an adsorber input operatively coupled to the first valve output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output;
a catalytic soot filter having a soot filter input operatively coupled to the adsorber output and the bypass output and having a soot filter output; and
a sulfur trap having a sulfur trap input operatively coupled to the engine exhaust and having a sulfur trap output operatively coupled to the valve system input.
17. The system of claim 16 , further comprising:
a temperature and lamda sensor having a sensor input operatively coupled to the valve system input.
18. The system of claim 16 , further comprising:
an NOx sensor having an NOx sensor input operatively coupled to the adsorber output.
19. The system of claim 16 , wherein the valve system comprises a proportional control 3-way valve.
20. The system of claim 16 , further comprising:
a supply of fuel;
a pump having a pump inlet operatively coupled to the supply of fuel and having a pump outlet;
a fuel injector having an injector input operatively coupled to the pump outlet and having an injector output operatively coupled to the adsorber input.
21. The system of claim 20 , further comprising:
an igniter operatively coupled to the adsorber input.
22. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a catalytic soot filter having a soot filter input operatively coupled to the engine exhaust and having a soot filter output;
a sulfur trap having a sulfur trap input operatively coupled to the filter output and having a sulfur trap output;
a valve system having a valve input operatively coupled to the sulfur trap output, a first valve output and having a second valve output;
an NOx adsorber having an adsorber input operatively coupled to the first valve output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output operatively coupled to the adsorber output; and
a diesel oxidation catalyst having a DOC input operatively coupled to the adsorber output and to the bypass output and having a DOC output.
23. The system of claim 22 , further comprising:
a temperature and lamda sensor having a sensor input operatively coupled to the valve system input.
24. The system of claim 22 , further comprising:
an NOx sensor having an NOx sensor input operatively coupled to the adsorber output.
25. The system of claim 22 , wherein the valve system comprises a proportional control 3-way valve.
26. The system of claim 22 , further comprising:
a supply of fuel;
a pump having a pump inlet operatively coupled to the supply of fuel and having a pump outlet;
a fuel injector having an injector input operatively coupled to the pump outlet and having an injector output operatively coupled to the adsorber input.
27. The system of claim 26 , further comprising:
an igniter operatively coupled to the adsorber input.
28. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a valve system having a valve input operatively coupled to the engine exhaust, a first valve output and having a second valve output;
a catalytic soot filter having a soot filter input operatively coupled to the valve system output and having a soot filter output;
an adsorber having an adsorber input operatively coupled to the soot filter output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output operatively coupled to the adsorber output; and
a diesel oxidation catalyst having a DOC input operatively coupled to the adsorber output and to the bypass output and having a DOC output.
29. The system of claim 28 , further comprising:
a temperature and lamda sensor having a sensor input operatively coupled to the valve system input.
30. The system of claim 28 , further comprising:
an NOx sensor having an NOx sensor input operatively coupled to the adsorber output.
31. The system of claim 28 , wherein the valve system comprises a proportional control 3-way valve.
32. The system of claim 28 , further comprising:
a supply of fuel;
a pump having a pump inlet operatively coupled to the supply of fuel and having a pump outlet;
a fuel injector having an injector input operatively coupled to the pump outlet and having an injector output operatively coupled to the soot filter input.
33. The system of claim 32 , further comprising:
an igniter operatively coupled to the soot filter input.
34. An internal combustion engine aftertreatment system for treating exhaust gases exiting an engine, the system comprising:
a valve system having a valve input operatively coupled to the engine exhaust, a first valve output and having a second valve output;
an adsorber having an adsorber input operatively coupled to the first valve output and having an adsorber output;
a bypass pathway having a bypass input operatively coupled to the second valve output and having a bypass output;
a catalytic soot filter having a soot filter input operatively coupled to the adsorber output and the bypass output and having a soot filter output;
a temperature and lamda sensor having a sensor input operatively coupled to the valve system input;
a supply of fuel;
a pump having a pump inlet operatively coupled to the supply of fuel and having a pump outlet; and
a fuel injector having an injector input operatively coupled to the pump outlet and having an injector output operatively coupled to the adsorber input.
35. The system of claim 34 , further comprising:
an igniter operatively coupled to the adsorber input.
36. The system of claim 34 , further comprising:
an NOx sensor having an NOx sensor input operatively coupled to the adsorber output.
37. The system of claim 34 , wherein the valve system comprises a proportional control 3-way valve.