Each of the millions of cars on Earth's roads is a source of air pollution. This is especially true in large cities, where car exhaust fumes are a problem. To solve them, each country issues its own laws that limit the permissible level of pollution.
Automobile manufacturers have made many improvements in the design of their engines and fuel systems to meet these requirements. One of the major changes occurred in 1975 when a new device called a catalytic converter (converter) or simply a catalyst was introduced. The work of the catalytic converter is to convert harmful exhaust gases into less harmful ones before they leave the vehicle exhaust system. The air-to-fuel ratio should be as close as possible to the ideal point. In theory, with this ratio, all fuel will burn completely, using all the oxygen in the air. In reality, however, there is no perfect combustion, although the developers of engines strive for it. The main engine emissions are nitrogen gas (N2), carbon dioxide (CO2) and water vapor. Basically, they are not dangerous. But when the engine of a car is emitted and a small amount of much more harmful exhaust gases. For example, carbon monoxide (CO), nitrogen oxides (NO and NO2).
As we know from chemistry, a catalyst is a substance that accelerates or causes a chemical reaction without being a part of the reaction products. In catalytic converters, there are two different types of catalysts - reducing and oxidizing. Some converters even use gold, which is cheaper than the already mentioned catalysts.
Most modern exhaust systems in cars are equipped with three catalytic converters, one for each of the substances that need to be reduced.
The catalytic converter significantly reduces environmental pollution, but its performance can be even greater. One of the drawbacks is that all reactions only take place at a sufficiently high temperature. For example, when you start the machine, the inverter is barely working. Therefore, a good way to reduce emissions is to preheat the inverter itself with an electric heater. Unfortunately, the car's 12-volt electrical system cannot do this fast enough. But this is not a problem in hybrid machines, they have large high-voltage batteries that can heat a car's catalyst in seconds.
Many car owners are looking for information on how to repair a catalyst. Actually, there are three options:
1. Replacement with an original neutralizer.
It is carried out by official dealers. Its main minus is in the price. The new part for such cars as Mercedes, Audi, Volkswagen, Honda, Mazda, and other popular foreign cars costs an average of 1000 - 1500 U.S. dollars. Given that most modern cars with engines over 1.6 liters have two, three and even four catalysts, it is easy to understand the final cost of such repairs.
2. Replacement with a universal catalyst.
Now almost all manufacturers of exhaust systems produce universal models of catalysts, which can replace the original parts. They are made a little easier than the original products. Sometimes the manufacturer saves on spraying. In this case, the exhaust may "fail" to comply with the EURO 4 standard. This should be taken into account when choosing a universal catalyst. Therefore, it is better to use only certified products of leading brands - Eberspacher, Bosal, Ferroz, Walker and some others, which meet the EURO 4 environmental standard. The service life is practically the same.
3. Replacing the catalyst with a flame arrester.
Any catalyst can be replaced with a flame arrester, which is a pipe, with chambers to reduce the speed and temperature of gases. An undeniable plus of such a replacement in the reliability of the entire design, which should serve more than 10 years. On average, the installation of one flamegasitor along with the deception of the Yamada probe is 8 - 10 thousand rubles. But a flamegasitor cannot remove harmful exhaust gases, unlike a catalyst. In Russia there are quite liberal norms for the content of harmful impurities in exhaust gases and the use of machines with flame arresters are allowed by law. However, in the case of travel by car abroad, the presence of a catalyst may be mandatory.
The systems of the struggle for clean air will be further improved along with the development of the global automotive industry. A significant role in this matter should be played by improving the quality of motor fuel alternative to gasoline and diesel. Today, the environmental friendliness of the car most often fits into the formula "price-quality".