Effect of Hydrocarbon Type on Reactivity of Exhaust Gases

Unburned hydrocarbons and other products of combustion are recognized as contributors to photochemical air pollution. The work reported here was a first approach in finding an expression of exhaust gas quality -- or compositional characteristic--that would associate directly with the photochemical activity of the composite sample.

Olefins, aromatics, and partial oxidation products have been cited as the principal smog precursors in exhaust gas. However, results of this study indicate that for the general case, collective determination of these classes provides an unreliable indication of reactivity. The findings are expected to be useful in further development of methods to measure -- or predict -- the air polluting potential of exhaust gas with increased reliability.