Method for reducing emissions from evaporative emissions control systems
US6540815B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2002 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Mar 18, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S95/90
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Disclosed is a method for sharply reducing diurnal breathing loss emissions from automotive evaporative emissions control systems by providing multiple layers, or stages, of adsorbents. On the fuel source-side of an emissions control system canister, high working capacity carbons are preferred in a first canister (adsorb) region. In subsequent canister region(s) on the vent-side, the preferred adsorbent should exhibit a flat or flattened adsorption isotherm on a volumetric basis and relatively lower capacity for high concentration vapors as compared with the fuel source-side adsorbent. Multiple approaches are described for attaining the preferred properties for the vent-side canister region. One approach is to use a filler and/or voidages as a volumetric diluent for flattening an adsorption isotherm. Another approach is to employ an adsorbent with the desired adsorption isotherm properties and to process it into an appropriate shape or form without necessarily requiring any special provision for dilution. The improved combination of high working capacity carbons on the fuel source-side and preferred lower working capacity adsorbent on the vent-side provides substantially lower diur…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.