Evaporative fuel vapor emission control systems

Patent metadata

Field	Value
Publication number	US-10960342-B2
Application number	US-201415028293-A
Country	US
Kind code	B2
Filing date	Apr 9, 2014
Priority date	Oct 10, 2012
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr BETP butane loading step.

First claim

The invention claimed is:

1. A low purge evaporative emissions control canister system comprising:
a fuel-side adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane; and
at least one vent-side adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane,
wherein the at least one vent-side adsorbent volume is a honeycomb structure configured without partial cells which facilitates uniform air and vapor flow distribution and an effective butane working capacity (BWC) of less than 3 g/dL and a g-total BWC of from 2 to 6 grams,
wherein the fuel-side and at least one vent-side adsorbent volumes are in fluid communication, and
wherein the canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than a bout 210 liters of purge applied after a 40 g/hr BETP butane loading step;
wherein low purge is defined as no more than about 210 liters of purge applied after a 40 g/hr butane loading step.

2. The canister system of claim 1 , wherein the fuel-side adsorbent volume and at least one vent-side adsorbent volume are located within a single canister.

3. The canister system of claim 1 , wherein the fuel-side adsorbent volume and at least one vent-side adsorbent volumes are located within separate canisters, and wherein the adsorbent volumes are in fluid communication.

4. The canister system of claim 2 , further comprising at least one additional vent-side adsorbent volume located within a separate canister, wherein adsorbent volumes are in fluid communication.

5. The canister system of claim 1 , comprising a single vent-side adsorbent volume.

6. The canister system of claim 1 , wherein the fuel-side adsorbent volume, the at least one vent-side adsorbent volume, or both includes an adsorbent selected from the group consisting of activated carbon, carbon charcoal, zeolites, clays, porous polymers, porous alumina, porous silica, molecular sieves, kaolin, titania, ceria, and combinations thereof.

7. The canister system of claim 6 , wherein the activated carbon is derived from a material including a member selected from the group consisting of wood, wood dust, wood flour, cotton linters, peat, coal, coconut, lignite, carbohydrates, petroleum pitch, petroleum coke, coal tar pitch, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, synthetic polymer, natural polymer, lignocellulosic material, and combinations thereof.

8. The canister system of claim 1 , wherein the at least one vent-side adsorbent volume includes a volumetric diluent.

9. The canister system of claim 8 , wherein the volumetric diluent includes a member selected from the group consisting of inert spacer particles, trapped air spaces, foams, fibers, screens, and combinations thereof.

10. The canister system of claim 9 , wherein the volumetric diluent includes an adsorbent material formed into a high voidage shape selected from the group consisting of stars, hollow tubes, asterisks, spirals, cylinders, configured ribbons, honeycombs, monoliths, and combinations thereof.

11. The canister system of claim 1 , wherein the at least one vent-side adsorbent volume has a total volume butane working capacity of from 3 to 5 grams.

12. The canister system of claim 1 , wherein the canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 157.5 liters of purge applied after the 40 g/hr BETP butane loading step.

13. The canister system of claim 1 , wherein the canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than about 100 bed volume of purge applied after the 40 g/hr BETP butane loading step.

14. The canister system of claim 1 , wherein the canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than about 75 bed volume of purge applied after the 40 g/hr BETP butane loading step.

15. An evaporative emissions control system, comprising:
a fuel tank for storing fuel;
an engine having an air induction system and adapted to consume the fuel;
an evaporative emission control canister system having a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than about 210 liters of purge applied after a 40 g/hr butane loading step, the canister system comprising:
a fuel-side adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane;
at least one vent-side adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, wherein the at least one vent-side adsorbent volume is a honeycomb structure configured without partial cells that facilitates uniform air and vapor flow distribution and an effective butane working capacity (BWC) of less than 3 g/dL and a g-total BWC of from 2 to 6 grams;
a fuel vapor inlet conduit connecting the evaporative emission control canister system to the fuel tank;
a fuel vapor purge conduit connecting the evaporative emission control canister system to the air induction system of the engine; and
a vent conduit for venting the evaporative emission control canister system and for admission of purge air to the evaporative emission control canister system;
wherein the evaporative emission control canister system is defined by a fuel vapor flow path from the fuel vapor inlet conduit to the fuel-side adsorbent volume toward the at least one vent-side adsorbent volume and the vent conduit, and by an air flow path from the vent conduit to the at least one vent-side adsorbent volume toward the fuel-side adsorbent volume and the fuel vapor purge outlet.

16. The evaporative emissions control system of claim 15 , wherein the canister system comprises one or more canisters.

17. The evaporative emission control system of claim 15 , wherein the fuel-side adsorbent volume and the at least one vent-side adsorbent volume of the canister system are located within a single canister.

18. The evaporative emission control system of claim 15 , wherein the fuel-side adsorbent volume and the at least one vent-side adsorbent volume are located in separate canisters, and wherein the adsorbent volumes are in fluid communication.

19. The evaporative emission control system of claim 17 , further comprising at least one additional vent-side adsorbent volume located within a separate canister, wherein the adsorbent volumes are in fluid communication.

20. The evaporative emission control system of claim 15 , further comprising a heat unit.

21. The evaporative emission control system of claim 15 , wherein the canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 157.5 liters of purge applied after the 40 g/hr BETP butane loading step.

22. The evaporative emission control system of claim 15 , wherein the canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 100 BV of purge applied after the 40 g/hr BETP butane loading step.

23. The evaporative emission control system of claim 15 , wherein the canister system has a two-day diurnal breathing loss (DB

Assignees

• Ingevity South Carolina Llc

Inventors

• Hiltzik Laurence H
• Mccrae Peter D
• Miller James R
• Williams Roger S

Classifications

• F02M25/0854 Primary

  Details of the absorption canister · CPC title

• B01D2257/7022

  Aliphatic hydrocarbons · CPC title

• F02M25/0872

  Details of the fuel vapour pipes or conduits · CPC title

• B01D2259/401

  using a single bed · CPC title

• B01D53/0415 Primary

  Beds in cartridges · CPC title