Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Small engine emissions and their impact

Conference ·
OSTI ID:7346676

In an attempt to characterize emissions from small air-cooled utility engines, five gasoline-fueled models were operated over a variety of speeds and loads, and important exhaust constituents were measured. These emissions included hydrocarbons, nitric oxide, carbon monoxide, carbon dioxide, oxygen, aldehydes, light hydrocarbons, particulates, and smoke. Emissions of sulfur oxides were estimated on the basis of the fuel consumed; evaporative losses of HC were also estimated. The impact of small engine emissions was calculated on the basis of the test results and information on national engine populations and usage. The 50 million or more small engines currently being used account for only a small part of the pollution from all sources. As percentages of the 1970 totals from all sources, small engines appear to nationally account for approximately 0.4% of HC, 0.8% of CO, 0.06% of nitrogen oxides, 0.004% of SO/sub x/, and 0.01% of particulates. As percentages of 1970 mobile source emissions, small engines are responsible for about 0.7% of HC, 1.0% of CO, 0.1% of NO/sub x/, 0.2% of SO/sub x/, and 0.5% of particulates. About 6% of the small engine emissions occur in the northern region, 52% in the central region, and 42% in the southern region. The emission factors for small engines under different load conditions and for different engine applications such as lawn and garden work are discussed.

OSTI ID:
7346676
Country of Publication:
United States
Language:
English