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U.S. Department of Energy
Office of Scientific and Technical Information

Mobile source inventory of benzene emissions in the State of California

Thesis/Dissertation ·
OSTI ID:5965802

In response to the environmental concern regarding benzene as an air contaminant, a statewide mobile source emission inventory was developed. Calculations are based on the evaporative and exhaust benzene fraction of total hydrocarbon emitted from each vehicle class. Exhaust benzene fractions of light-duty passenger vehicles (which generate the majority of THC emissions from mobile sources) were calculated as .023 for diesel vehicles, .028 for vehicles equipped with oxidation catalysts, .042 for non-catalyst vehicles, and .055 for vehicles equipped with three-way catalysts. Evaporative benzene fractions were assumed to be .012 for all gasoline-powered vehicles and zero for diesel-powdered vehicles. Evaporative benzene emissions were found to contribute approximately 13% of statewide benzene emissions from mobile sources, and the remainder contributed by exhaust emissions. Two scenarios were utilized to estimate benzene emissions to the year 2000. Scenario 1 treated all catalyst-equipped light-duty passenger vehicles as having a benzene fraction identical to that of oxidation catalysts, whereas Scenario 2 subdivided catalyst-equipped vehicles into those with oxidation catalysts and those with three-way catalysts. Some of the more important issues requiring further study include: 1) the contribution of malfunctioning vehicles to the benzene emissions inventory, 2) a more detailed look at the level of exhaust benzene emitted from three-way catalyst vehicles, and 3) the relationship of exhaust benzene to its fuel content, combustion, and catalysis.

OSTI ID:
5965802
Country of Publication:
United States
Language:
English