Factors Influencing the Composition and Quantity of Passenger Car Refueling Emissions. Part 2

摘要

The study measured and characterized refueling emissions from a 1986 Pontiac Grand Am using 3 test fuels, including a winter, summer and intermediate blend gasoline under a variety of seasonal temperature conditions. It investigated three major parameters that affect refueling emissions: fuel volatility, expressed as Reid Vapor Pressure (RVP); dispensed fuel temperature (Td); and tank fuel temperature (Tt). In the study, RVP varied from 10.0 to 13.3 psi, Td varied from 50 to 88 F, and Tt varied from 40 to 108 F, while the overall hydrocarbon (HC) refueling emission rate ranged from 2.90 to 7.41 grams/gallon. Detailed hydrocarbon analyses were completed for both the test fuels (dispensed fuel and tank fuel) and the refueling vapor. The overall mean (from all test fuels and temperature scenarios) HC emission rate was 4.69 g/gal; the mean refueling vapor was comprised of 79.7% paraffins, 13.6% olefins, 5.8% aromatics, with an average carbon number of 4.76; overall mean test gasoline was comprised of 39.5% paraffins, 7.7% olefins 49.0% aromatics, with an average carbon number of 7.30. Butanes and pentanes comprised about 70% of the total HC refueling vapor.