This report documents the investigation of the technical and economic feasibility of using a carbon canister on board the vehicle to retain displaced hydrocarbon vapors during refueling. Denoted by the API as an Interim Report of Project EF-14, this report is a sequel to the Project's Phase I Report of April 1973, “Cost Effectiveness of Methods to Control Vehicle Refueling Emissions.”
To initiate the design of a prototype carbon canister system capable of handling refueling vapor losses, studies were undertaken on a bench-test system to define the total amount of refueling vapor to be handled, vapor retention capacity of activated carbon, and purge capacity over a range of refueling conditions and fuel system parameters. In addition, extensive exhaust and evaporative emission tests were performed on the baseline vehicle and the modified vehicle. Detailed cost and effectiveness analyses were performed.
The study shows that this type of control is technically feasible for refueling and evaporative emissions, fuel savings can approach the cost of the refueling control system, driveability was not impaired, and exhaust CO emissions increased.