Why is a catalyst essential?
The internal combustion engine of a passenger car, with a volume of 1,500 cm³ per hour, produces 150 cubic meters of exhaust gas. These exhaust gases, contain up to 14% carbon dioxide and up to 1% argon and other pollutants including heavy metals.
Polluted exhaust gases pose a serious threat to the environment, and thus to human health. Therefore, devices have been designed to reduce the environmental impact of road transport: the catalytic converter, or car catalytic converter.
The catalytic converter in a car reduces emissions of carbon monoxide and dioxide, hydrocarbons (HC), nitrogen oxides (NOx) and heavy metals. An efficient catalytic converter is capable of reducing emissions by up to about 95%.
How is a catalytic converter built and how does it work?
The catalytic converter consists of a ceramic or metal catalytic cartridge placed in a box mounted just behind the exhaust manifold. The cartridge is usually surrounded by heat shields due to the nature of the device's operation, which requires high temperatures - usually 400 to 800 degrees Celsius. The cartridge with its structure resembles a honeycomb. This structure is covered with a layer of precious metals, whose task is to enter into chemical reactions that neutralize harmful substances contained in car exhaust.
A high temperature is required to purify the exhaust gas, because only at about 700 degrees do catalytic reactions take place. Therefore, the catalytic converter works most effectively when the cartridge is heated, for which the exhaust gases are responsible.
Catalytic converter replacement
Like all car parts, the catalytic converter is also subject to wear and tear. It is estimated that the replacement of the catalytic converter should occur, depending on the type of cartridge, after 100 to 200 thousand kilometers.
A poor condition of the catalytic converter can manifest itself in very different ways, but the most common are a decrease in engine power, noises coming from the exhaust system, an increase in fuel consumption or even the check engine light coming on.
It is absolutely forbidden to remove the catalytic converter from the exhaust system. A worn-out catalytic converter must be replaced, preferably with a new one, otherwise the vehicle will not pass tests at a diagnostic station due to excessively high levels of exhaust pollution.