This paper reviews the source of the different emissions from an automobile. The exhaust is the major source of air pollution. This is composed of completely oxidized constituents such as H2O and CO2, both of which are considered harmless. Emphasis is placed on the partially oxidized components -- nitrogen oxide, carbon monoxide, and hydrocarbons -- as being the major pollutants. NO and CO are formed primarily in the bulk gases, whereas hydrocarbons are formed in the quench area.
Discussed are several possible methods that could be considered in attempting to eliminate these pollutants. The authors are confident an answer will be found to this emission problem and that internal combustion engines will be used to power private vehicles rather than electricity.