Atmospheric chemistry studies of exhaust from vehicles operating with reformulated fuel
- ManTech Environmental Technology, Inc., Research Triangle Park, NC (United States)
- Environmental Protection Agency, Research Triangle Park, NC (United States). National Exposure Research Lab.
In many areas of the US, ozone concentrations continue to be higher than that specified by the NAAQS. In spite of substantial improvements, automobile exhaust is still one of the major sources of ozone precursors, reactive organic gases and oxides of nitrogen. One strategy for dealing with this emission source is to use fuels that have lower reactivities than conventional gasoline. Thus, a wide range of fuels have been proposed to implement this approach, including reformulated gasoline, methanol and ethanol enhanced fuels, compressed natural gas, liquid propane fuel, among others. The degree of ozone reduction expected from these fuels has only been estimated using reactivity scales which are largely based on modeling results. Further truth testing of model performance is thus required. The present project is being conducted to help validate the predicted ozone forming potential of exhaust mixtures by experimental means and to evaluate the reaction products formed during the photochemical oxidations. In this work, exhaust from vehicles operating on reformulated fuels was generated using the Federal Test Procedure. Exhaust was collected during the first 124 seconds of the FTP and was then injected into a 9,000 L Teflon irradiation chamber. Irradiations were conducted at a reactive organic gas (ROG)/NO{sub x} ratio of 5.5 to accentuate differences in hydrocarbon composition. In cases where the initial ratio was less than the target ratio, an ROG exhaust surrogate was added. The results of irradiations of exhaust mixtures from a single vehicle operated with reformulated gasoline are presented along with time series profiles for the major photochemical reaction products including ozone, nitrogen dioxide, formaldehyde, acetaldehyde, acetone, peroxyacetyl nitrate (PAN), nitric acid, and tertiary-butyl formate. Mechanisms for forming these products from the major exhaust precursors are also considered.
- OSTI ID:
- 351026
- Report Number(s):
- CONF-970677-; TRN: IM9925%%188
- Resource Relation:
- Conference: 90. annual meeting and exhibition of the Air and Waste Management Association, Toronto (Canada), 8-13 Jun 1997; Other Information: PBD: 1997; Related Information: Is Part Of 1997 proceedings of the Air and Waste Management Association`s 90. annual meeting and exhibition; PB: [7000] p.
- Country of Publication:
- United States
- Language:
- English
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