Method and system for reducing emissions from evaporative emissions

摘要

A method for reducing hydrocarbon emissions from automotive evaporative emissions control systems comprising steps of: contacting a vented fuel vapor stream from a fuel tank (1) with a first passive purge canister bed (5), the passive purge canister bed comprising a vapor adsorbent material and including a passive purge vapor inlet and a passive purge vapor outlet for vapor stream flow, —contacting a vapor stream from the passive purge vapor outlet with an active purge canister bed, the active purge canister bed (2) comprising a vapor adsorbent material; contacting the active purge canister bed with mechanically convected purge air, wherein the mechanically convected purge air is prevented from flowing through the passive purge canister bed; and contacting the passive purge canister bed with fresh purge air drawn passively by the fuel tank through the passive purge vapor outlet without first contacting said active purge canister bed.

主权项

1. A method of reducing fuel vapor emissions in an automotive evaporative emissions control system for a vehicle comprising steps of:
(a) contacting a vented fuel vapor stream from a fuel tank with a first passive purge canister bed, the passive purge canister bed comprising a vapor adsorbent material and including a passive purge vapor inlet and a passive purge vapor outlet for vapor stream flow; (b) contacting the vapor stream from the passive purge vapor outlet with an active purge canister bed, the active purge canister bed comprising a vapor adsorbent material; (c) contacting the active purge canister bed with mechanically convected purge air, wherein the mechanically convected purge air is prevented from flowing through the passive purge canister bed; and (d) contacting the passive purge canister bed with fresh purge air drawn passively by the fuel tank through the passive purge vapor outlet without first contacting the active purge canister bed;
wherein the vented fuel vapor stream is prevented from being vented to an atmosphere without contacting both the passive purge canister bed and the active purge canister bed.