What is the reason for the excessive emission of automobile exhaust? What pollution will it cause?

Refined oil is generally used as the main raw material in automobile fuel refining, which easily leads to high olefin content in gasoline. In the process of automobile fuel refining, if there is olefin unsaturation or excessive hydrocarbon substances, it is easy to increase the emission of carbon monoxide and hydrocarbons. At present, some refined oil products do not meet the corresponding standards, which eventually leads to excessive sulfur, lead and silicon content.

With the development of social economy, many families buy cars as a means of transportation, but do not pay attention to the maintenance of cars, resulting in excessive exhaust gas. Usually, when the traffic is busy, the automobile engine will produce more harmful gases. If the harmful gas exceeds the standard, it will affect human health.

Generally, the richer the mixture, the less complete the combustion, and the emissions of nitrogen oxides have little change, but the emissions of hydrocarbons and carbon dioxide will increase significantly; The thinner the mixture is, the more complete the combustion is, and the emissions of hydrocarbons and carbon dioxide are obviously reduced, but the emissions of nitrogen oxides are increased. Therefore, people should use lean mixture as much as possible to effectively reduce the emission of harmful gases and achieve the effect of fuel saving. However, in the actual application process, it is necessary to fully meet the air-fuel ratio requirements of the engine and effectively prevent the engine power from falling or even stalling.

Nitrogen oxides are the products of high temperature combustion of engine fuel. When the speed and load of automobile engine increase, the combustion temperature of engine cylinder will increase, which will lead to the increase of nitrogen oxide emissions and carbon monoxide and hydrocarbon emissions.

Nitrogen oxides are extremely harmful. Once they enter human eyes, respiratory tract or alveoli, they will form nitrous acid or nitric acid, which will cause serious damage to human tissues. Nitrogen oxides and hydrocarbons will undergo a series of chemical reactions after being irradiated by ultraviolet rays, forming toxic photochemical smog, stimulating people to shed tears, causing red eyes and acute wheezing, and causing poisoning. In addition, photochemical smog can damage plants and reduce atmospheric visibility.

Automobile exhaust contains a lot of solid particles. The main component of solid particles is carbon black. If the diesel fuel is not completely burned, a large amount of carbon black will appear, which will affect people's respiratory system. In addition, automobile exhaust also contains carbon dioxide. If the concentration of carbon dioxide in the air is too high, it will easily lead to the greenhouse effect, lead to the melting of the Antarctic and Arctic ice sheets, cause the sea level to rise, and directly affect the ecological environment.