A photochemical modeling study was conducted to estimate the impact on smog production resulting from the substitution of methanol fuel for gasoline and diesel fuel in Philadelphia in the year 2000. Three photochemical models were used: a comprehensive grid model adapted from the Urban Airshed Model (UAM), a four-cell trajectory model (a Lagrangian version of the UAM), and a single-cell box model. Emission rates, initial conditions, and boundary values were forecast to the year 2000. Model sensitivity tests indicate that methanol substitution above 20 percent of the overall Volatile Organic Compound inventory may significantly inhibit smog formation, but the reduction also depends strongly on other factors such as formaldehyde emissions, methanol carryover from upwind sources or previous days, and NOx levels. Whereas formaldehyde emissions tend to accelerate ozone formation, methanol carryover and NOx emissions tend to decrease ozone formation.

Includes bibliographical references (p. 123-124). "EPA 460/3-86-001." "March 1986." "Contract No. 68-02-3870, Work Assignment 6"--T.p. "EPA Project Officer: Thomas N. Braverman"--T.p. "Technical Representative: Penny M. Carey"--T.p.