Claims
- 1. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, and a vent/air inlet; and a secondary canister coupled to said vent/air inlet and containing a second volume of a second adsorbent material that is different than said first adsorbent material, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running; and wherein said second adsorbent material adsorbs butanes and pentanes at low concentrations.
- 2. The evaporative emissions system of claim 1 wherein said evaporative emissions system reduces bleed emissions below 4 mg/day.
- 3. The evaporative emissions system of claim 1 wherein said engine is integrated with a hybrid powertrain.
- 4. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, and a vent/air inlet; and a secondary canister coupled to said vent/air inlet and containing a second volume of a second adsorbent material that is different than said first adsorbent material, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running; and wherein said second adsorbent material includes activated carbon derived from a coconut shell.
- 5. The evaporative emissions system of claim 4 wherein said secondary canister includes a housing, a heater located outside of said housing and a heat sink located inside of said housing, wherein said heater heats said heat sink and said heat sink heats said secondary volume of said second adsorbent material.
- 6. The evaporative emissions system of claim 5 wherein said heat sink includes a plurality of spaced plates that are coated with said second adsorbent material.
- 7. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, and a vent/air inlet; and a secondary canister coupled to said vent/air inlet and containing a second volume of a second adsorbent material that is different than said first adsorbent material, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running; and wherein said secondary canister includes a housing and a heater that heats said secondary volume of said second adsorbent material.
- 8. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, and a vent/air inlet; and a secondary canister coupled to said vent/air inlet and containing a second volume of a second adsorbent material that is different than said first adsorbent material, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running; and wherein said first adsorbent material includes activated carbon derived from wood.
- 9. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; and a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, a vent/air inlet, and a second volume of a second adsorbent material that is different than said first adsorbent material and that is located between said first volume and said vent/air inlet, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running; and wherein said second adsorbent material adsorbs butanes and pentanes at low concentrations.
- 10. The evaporative emissions system of claim 9 wherein said second volume is heated by a heater.
- 11. The evaporative emissions system of claim 9 wherein said evaporative emissions system reduces bleed emissions below 4 mg/day.
- 12. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; and a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, a vent/air inlet, and a second volume of a second adsorbent material that is different than said first adsorbent material and that is located between said first volume and said vent/air inlet, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running; and wherein said second adsorbent material includes activated carbon derived from a coconut shell.
- 13. The evaporative emissions system of claim 12 wherein said engine is integrated with a hybrid powertrain.
- 14. An evaporative emissions control system for a vehicle, comprising:a fuel tank for storing a volatile fuel; an engine having an air induction system; a primary canister containing a first volume of a first adsorbent material, a vapor inlet coupled to said fuel tank, a purge outlet coupled to said air induction system, a vent/air inlet, and a second volume of a second adsorbent material that is different than said first adsorbent material and that is located between said first volume and said vent/air inlet; and a heater located outside of said second volume and a heat sink located inside of said second volume, wherein said heater heats said heat sink and said heat sink heats said secondary volume of said second adsorbent material, wherein said first and second adsorbent materials adsorb fuel vapors when said engine is not running to reduce bleed emissions and desorb fuel vapors when said engine is running.
- 15. The evaporative emissions system of claim 14 wherein said heat sink includes a plurality of spaced plates that are coated with said second adsorbent material.
- 16. A method for reducing bleed emissions from an evaporative emissions control system for a vehicle, comprising:storing a volatile fuel in a fuel tank; providing a primary canister containing a first volume of a first adsorbent material; coupling a vapor inlet of said primary canister to said fuel tank; coupling a purge outlet of said primary canister to an air induction system of an engine of said vehicle; coupling a secondary canister containing a second volume of a second adsorbent material to said vent/air inlet, wherein said second adsorbent material is different than said first adsorbent material; adsorbing fuel vapors when said engine is not running using said first and second adsorbent materials; desorbing fuel vapors from said first and second adsorbent materials when said engine is running; and adsorbing butanes and pentanes at low concentrations using said second adsorbent material.
- 17. The method of claim 16 further comprising heating said secondary volume of said second adsorbent material.
- 18. The method of claim 16 wherein said evaporative emissions system reduces bleed emissions below 4 mg/day.
- 19. A method for reducing bleed emissions from an evaporative emissions control system for a vehicle, comprising:storing a volatile fuel in a fuel tank; providing a primary canister containing a first volume of a first adsorbent material; coupling a vapor inlet of said primary canister to said fuel tank; coupling a purge outlet of said primary canister to an air induction system of an engine of said vehicle; coupling a secondary canister containing a second volume of a second adsorbent material to said vent/air inlet, wherein said second adsorbent material is different than said first adsorbent material; adsorbing fuel vapors when said engine is not running using said first and second adsorbent materials; and desorbing fuel vapors from said first and second adsorbent materials when said engine is running, wherein said second adsorbent material includes activated carbon derived from a coconut shell.
- 20. A method for reducing bleed emissions from an evaporative emissions control system for a vehicle, comprising:storing a volatile fuel in a fuel tank; providing a primary canister containing a first volume of a first adsorbent material; coupling a vapor inlet of said primary canister to said fuel tank; coupling a purge outlet of said primary canister to an air induction system of an engine of said vehicle; coupling a secondary canister containing a second volume of a second adsorbent material to said vent/air inlet, wherein said second adsorbent material is different than said first adsorbent material; adsorbing fuel vapors when said engine is not running using said first and second adsorbent materials; desorbing fuel vapors from said first and second adsorbent materials when said engine is running; and locating a heater outside of said secondary volume and a heat sink inside of said secondary volume.
- 21. The method of claim 20 wherein said heat sink includes a plurality of spaced plates that are coated with said second adsorbent material.
- 22. A method of reducing breakthrough vapor escaping a fuel vapor storage and recovery system, comprising:providing a chamber containing coconut carbon; and using said coconut carbon in said chamber to reduce low concentrations of at least one of butanes and pentanes.
- 23. The method of claim 22 wherein said low concentrations are approximately between 0.1 and 0.5 percent.
- 24. The method of claim 22 wherein said pentanes are isopentanes.
- 25. The method of claim 22 wherein said fuel vapor storage and recovery system includes a primary canister and a secondary canister, and wherein said secondary canister defines said chamber.
- 26. The method of claim 22 wherein said fuel vapor storage and recovery system includes a primary canister having primary and secondary volumes, and wherein said secondary volume of said primary canister defines said chamber.
- 27. The method of claim 22 wherein said chamber contains less than 20 cc of said coconut carbon.
- 28. The method of claim 22 further comprising heating said coconut carbon.
- 29. A fuel vapor storage and recovery system comprising:a first chamber containing a first adsorbent that adsorbs fuel vapors and that purges said fuel vapors; and a second chamber in fluid communication with said first chamber that contains coconut carbon.
- 30. The fuel vapor storage and recovery system of claim 29 wherein said coconut carbon adsorbs low concentrations of at least one of butanes and pentanes.
- 31. The fuel vapor storage and recovery system of claim 30 wherein said low concentrations are approximately between 0.1 and 0.5 percent.
- 32. The fuel vapor storage and recovery system of claim 30 wherein said pentanes are isopentanes.
- 33. The fuel vapor storage and recovery system of claim 29 further comprising a heater that heats said coconut carbon.
- 34. The fuel vapor storage and recovery system of claim 33 wherein said coconut carbon is dispersed on surfaces heated by said heater.
- 35. The fuel vapor storage and recovery system of claim 29 wherein said fuel vapor storage and recovery system includes a primary canister defining said first chamber, and a secondary canister, and wherein said secondary canister defines said second chamber.
- 36. The fuel vapor storage and recovery system of claim 29 wherein said fuel vapor storage and recovery system includes a primary canister having primary and secondary volumes, and wherein said secondary volume of said primary canister defines said second chamber.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/293,475, filed May 25, 2001, which is hereby incorporated by reference.
US Referenced Citations (11)
Provisional Applications (1)
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Number |
Date |
Country |
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60/293475 |
May 2001 |
US |