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EFFECT OF HYDROCARBON COMPOSITION ON OXIDANT-HYDROCARBON RELATIONSHIPS. PHASE I. EXHAUST BLENDS FROM NON-CATALYST AND CATALYST EQUIPPED VEHICLES
Citation:
Powers, T. EFFECT OF HYDROCARBON COMPOSITION ON OXIDANT-HYDROCARBON RELATIONSHIPS. PHASE I. EXHAUST BLENDS FROM NON-CATALYST AND CATALYST EQUIPPED VEHICLES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-77/109a.
Description:
Oxidation catalysts on automobiles not only reduce the total amount of hydrocarbon emissions, but also change the composition of these emissions significantly. To explore the effect of this change on oxidant formation, 28 ten-hour irradiations were carried out in the Exxon Research Environmental Chamber. Fourteen of these irradiations used a hydrocarbon blend representative of the non-methane, non-acetylene exhaust hydrocarbon emissions from a non-catalyst equipped vehicle, and 14 used a blend representative of the same fraction of the emissions from a catalyst equipped vehicle. Irradiations were carried out at three hydrocarbon-to-nitrogen oxides ratios and with three modes of chamber operation, chosen to simulate different meteorological conditions. The results of these experiments indicate that the composition change due to oxidation catalysts will result in a significant alleviation, above that due to hydrocarbon concentration change alone, of the local effects of automotive tailpipe emissions.