Evaporation and Refueling Losses: Options for Control in Europe

Abstract

In the European Community, a compromise was found, which will lower the exhaust hydrocarbon emissions in the future. For the evaporative emissions it was not possible to reach an agreement on the measurement method. Two different proposed test methods (Shed test and Trap test) will be compared. The values obtained in the Trap-test are lower than those obtained in the Shed test. The results show that the traps do not collect the total evaporative emissions. Special measurements of the hydrocarbon emissions through the wall of plastic tanks produced very high emission values. Additionally 40 representative randomly selected spark igni-tioned engine vehicles were tested in order to determine emission factors for the evaporative emissions. Vehicles with a carbon canister trap have emissions 10 times lower than vehicles without a control system. A prediction of the evaporative emissions from vehicles with spark ignitioned engines was made for the Federal Republic of Germany based on a model which includes the temperature distribution in the Federal Republic of Germany and fuel composition. The evaporative emissions (without refueling emissions) were calculated to be about 220,000 t per year. This is about 26 % of the total hydrocarbon emissions from passenger vehicles. For the refueling emissions the situation in Europe will be described.