Abstract |
Fuel composition, engine deposits and vehicle emission-control systems have been studied as variables affecting the exhaust emissions of phenols and of polynuclear aromatic hydrocarbons (PNA, measured as benzo(a)pyrene (BaP) and benz(a)anthracene (BaA)). The exhaust from uncontrolled (1966) and engine-modification (EM (1968 and 1970) vehicles in 7-mode cyclic tests with cold starts was cooled and filtered to collect PNA and phenols. Emission rates, per gallon of fuel were determined. Standard calculated emission results for CO, HC and NO were obtained concurrently with the PNA tests. PNA emissions from the 1966 and 1968 vehicles were corrected to a uniform CO level for each vehicle. Fuel composition variables affecting emissions were found to have both direct effects, which were observed in short-term tests over existing engine deposits. (Author) |