Evaporative fuel vapor emission control systems
AssigneeIngevity South Carolina, LLC
InventorsLaurence H. Hiltzik, Peter D. Mccrae, James R. Miller, Roger S. Williams
Life of this patent
Estimating the term…
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.
Claims29
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 about 4.2 g/dL or a g-total BWC of less than about 6.1 grams or a combination thereof,
- 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 about 210 liters of purge applied after a 40 g/hr BETP butane loading step, and low-purge is defined as no more than about 210 liters of purge applied after a 40 g/hr BETP butane loading step.
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 about 4.2 g/dL or a g-total BWC of less than about 6.1 grams or a combination thereof;
- 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.
A method for reducing fuel vapor emissions in an evaporative emission control system, the method comprising contacting the fuel vapor with:
- 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 that facilitates uniform air and vapor flow distribution and an effective butane working capacity (BWC) of less than about 4.2 g/dL or a g-total BWC of at least about 6.1 grams or a combination thereof,
- wherein the fuel-side adsorbent volume and the at least one vent-side adsorbent volume are connected to permit sequential contact by fuel vapor, and wherein the canister system has 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 BETP butane loading step.
Dependencies are inferred from the claim text.