ANALYSIS OF METHODS FOR REDUCING THE HARMFUL EFFECTS OF EXHAUST GASES FROM AUTOMOBILE ENGINES.

Аннотация

Cars with internal combustion engines produce a lot of harmful emissions, causing environmental problems. These emissions reduce air quality, pollute water resources, and disrupt the overall ecological balance. Air pollution harms plants and animals, and also threatens human health, causing respiratory diseases, allergies, and other health problems. In addition, vehicle emissionslead topollutionof water bodies, which seriously harms theirecosystems. Key words: car engines, neutralizer, catalyst, exhaust gases, catalytic converters, carbon monoxide,catalytic neutralization, liquidneutralizers. The amount of nitrogen oxides (NOx) is significantly dependent on the temperature in the combustion chamber. When the temperature increases from 2500 K to 2700 K, the reaction rate increases by a factor of 2.6, and when it decreases from 2500 K to 2300 K, it decreases by a factor of 8. The higher the temperature, the higher the concentration of NOx. The fuel injection process or high pressure in the combustion chamber also increases the formation of NOx. High oxygen concentrations further increase theamount ofnitrogen oxides. Hydrocarbons are irritating to the mucous membranes (eyes, throat, nose) and play an important rolein theformation of biologically active substances that are harmful to theenvironment. Exhaust smoke (smog) consists of dust particles, liquid droplets (in humid conditions) and aerosols, and occurs in industrial cities under certain weather conditions. Gases released into the atmosphere react chemically with each other, forming new, including toxic, compounds. In this process, reactions such as photosynthesis, oxidation, polymerization, condensation, and catalysis occur. Neutralizers and catalysts are used to reducetheharmful effects ofexhaust gases. Catalytic converters are installed in the exhaust systems of cars. These neutralizers create chemical reactions in the exhaust gases, significantly reducing the release of toxic substances intotheatmosphere. Millions of cars are on the road around the world, and their engines produce large amounts of exhaust gases as a result of fuel combustion. The main components of car exhaust are nitrogen, water vapor, and carbon dioxide, which are harmless in themselves. However, excessive accumulation of carbon dioxide in the atmosphere can lead to the greenhouse effect and global climatechange. At the same time, car exhaust also contains small amounts of toxic substances such as carbon monoxide (CO), hydrocarbons, and nitrogen oxides. These gases are dangerous to humans and otherlivingorganisms. Catalytic neutralizers helpreduce therelease ofthese toxicsubstances. As the name suggests, catalytic converters use special catalysts. Two types of catalysts are considered more effective in neutralizing vehicle exhaust gases: the first are oxidizing catalysts and the second are reducing catalysts. A honeycomb-shaped metal catalyst is attached to a ceramic base. This ensures that the exhaust gas flow reaches the catalyst surface area to the maximumextent. The reducing catalyst is the first stage of neutralizing vehicle exhaust gases. In this case, a catalyst based on platinum or rhodium neutralizes nitrogen oxides, that is, decomposes them into https://ijmri.de/index.php/jmsi volume 4,issue7,2025 96 harmless oxygen and nitrogen: NO= N+O. In the next stage, the oxidizing catalyst comes into play: in it, a catalyst made of palladium and platinum neutralizes unburned hydrocarbon waste and carbon oxides. In this process, the catalyst oxidizes hydrocarbon waste, breaking them down intowater and CO2, and carbon dioxideis also converted into carbon dioxide. Some modern vehicles are also equipped with a third-stage exhaust gas control system, which controls the fuel delivery process to the engine by analyzing thequantitativevalues recorded bythesensor. Catalytic neutralization Many studies have been conducted using various catalysts to increase the efficiency of the oxidation of carbon monoxide (CO) and hydrocarbons (CH) in synthetic mixtures and exhaust gases. The most comprehensive results of these studies are summarized in the works of D.V. Sokolsky and P.M. Popova. Studies on the catalytic reduction of nitrogen oxides (NOx) are relatively few. To neutralize toxic substances in engine exhaust gases, it is necessary to provide two types of reactions: oxidation reactions (conversion of CO and CH to complete combustion products) and reduction reactions (decomposition of NOx to oxygen (O₂) and nitrogen (N₂)). Oxidation reactions can be carried out in two reactors, but to increase their efficiency, it is necessary to maintain a high temperature or extend the reaction time by increasing the reactor volume. Various design schemes for catalytic converters have been developed. Catalytic decontamination ofexhaust gases uses metal catalysts (platinum, palladium, monel metal, etc.) and catalysts based onmetal oxides (copper, nickel, chromium, iron, etc.). There are a number of difficultie