Impact of Reactivity Criteria on Organic Emission Control Strategies for Los Angeles

This paper investigates the impact of using alternative reactivity criteria to formulate organic control strategies for the Los Angeles Basin. It begins by establishing a consistent terminology for discussing reactivity concepts, followed by a brief description of the development of reactivity classification schemes. Three alternative classification schemes are proposed, based on a review of smog chamber data. An emission inventory of total organics, organized into 26 source categories, is assembled for the Los Angeles Basin. Composition data are presented for each source category. The composition data are tabulated according to the three proposed reactivity classification schemes and are used to determine average molecular weights, average source reactivities, and reactive emissions for each category. Results are presented on both a molar basis and a weight basis. The main features of the source reactivities and reactive emission inventory are discussed. The overall degree of reactive organic control needed to achieve the national oxidant standard in Los Angeles is evaluated. Because of high uncertainty in the required degree of control, 90% overall reduction is selected as an arbitrary target level for strategy analysis. Individual source emission reductions that attain 90% overall reactive organic control are determined for various reactivity schemes. These results are used to assess the impact of reactivity schemes on organic control strategies for Los Angeles.