An Experimental Study of Vehicle Refueling Emissions

When automobiles are refueled, hydrocarbon vapors are displaced from the vehicle tank and emitted to the atmosphere. An experimental program was carried out to measure both the mass and the volume of these emissions as a function of three variables: vehicle tank temperature, dispensed fuel temperature, and fuel volatility measured as Reid vapor pressure.

Based on the experimental results, regression equations were developed which can be used to accurately predict refueling emissions under a wide range of conditions.

An analysis of the experimental results shows that the vapor balance system, the simpler, less expensive of the two systems being considered for control of refueling emissions, has the potential to meet strict standards under temperature conditions where ozone is likely to form in the atmosphere.