What is the engine throwing out?

Carbon monoxide (SO), perhaps the most famous compound, because. in the engine idling, the CO content in the exhaust gases is measured. The richer the fuel-air mixture, the more it is formed. The lean mixture, precise ignition setting and even distribution of the mixture in the combustion chamber result in low levels of CO in the exhaust gases.

• Unburned hydrocarbons (NS) are formed if the flame front ignited by the spark plug goes out at the cold walls and in the narrow corners of the combustion chamber. Basically, the HC fraction is determined by the design of the engine, later on it can only be slightly influenced.
• nitrogen oxides (NC) are formed, first of all, due to nitrogen, which is contained by more than 3/4 in the combustible air. Their share is especially large when the engine is designed with a minimum fuel consumption and minimum CO and HC emissions. high combustion temperatures and a lean air-fuel mixture.
• Sulfur dioxide (SO₂) formed only in diesel engines due to the sulfur content in diesel fuel.

What and how dangerous?

• Carbon monoxide is poisonous and if inhaled indoors can be fatal. In the atmosphere, carbon monoxide combines with oxygen relatively quickly to form carbon dioxide (CO₂). It is not poisonous, but significantly affects the formation «greenhouse effect».
• Hydrocarbon compounds are presented as complex compounds, and their palette ranges from harmless to, in all likelihood, carcinogenic. In the atmosphere, hydrocarbon compounds with nitrogen oxides are responsible for the formation of smog (hardly soluble clouds of exhaust gases).
• O Nitrogen oxides, at appropriate concentrations in the atmosphere, are irritating to the respiratory system.

«Acid rain»

The proportion of harmful substances present in the atmosphere, which are also responsible for the formation of acid precipitation, is (data rounded to whole numbers):

• Sulfur compounds (SO₂): 35% natural, 65% human activity, of which 97% power plants, industry and heating, 3% transport (diesel cars).
• nitrogen oxides (NO_X): 95% natural origin, 5% result of human activity (half of them are transport).

Tip: Around the world, an increasing number «combustion centers» promotes the release of carbon dioxide. Decrease in areas of forests and vegetation cannot cope with the conversion of carbon dioxide into oxygen. The rest is distributed in the atmosphere. In combination with other substances, it enhances the opaque layer that reflects sunlight, experts establish climate change (Greenhouse effect).