Patent ID: 9732649
Date: 2017-08-15
CPC Classifications: B01D,B01J,F01N,F02M,Y02T

Claim:
1. An evaporative emission control canister system, including one or more canisters and comprising: 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, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams, wherein the initial adsorbent volume and the at least one subsequent adsorbent volume are located within a single canister, or the initial adsorbent volume and the at least one subsequent adsorbent volume are located in separate canisters that 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 the 40 g/hr butane loading step.