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Which pollutants are produced by gasoline engines?
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gasoline engine
Cross section of a V-type engine.
Gasoline engines produce several pollutants as by-products of their operation, primarily originating from the exhaust, the crankcase, and fuel evaporation.1
The primary pollutants emitted by gasoline engines include:
- Carbon monoxide: An odorless, invisible gas produced by incomplete combustion. It is the most abundant of the criteria pollutants and is a significant health hazard because it displaces oxygen in the bloodstream.23
- Hydrocarbons: These consist of unburned fuel compounds. They are discharged through the exhaust pipe, leak from the crankcase, and evaporate from the fuel tank and carburetor.31
- Nitrogen oxides: These are formed by the chemical reaction of nitrogen and oxygen at the high temperatures present during combustion.3
- Sulfur oxides: These are also discharged through the exhaust system.1
- Other substances: Exhaust gases may contain traces of various acids, alcohols, and phenols.1
To mitigate the environmental and health impacts of these emissions, modern vehicles utilize emission control systems, such as catalytic converters, to oxidize or reduce these pollutants into less harmful substances like water vapor, carbon dioxide, and nitrogen.41