What is in car exhaust. Car Exhaust Hazard

City dwellers often talk about ecology, and mostly scold it. In principle, there are many reasons for this, but they especially often talk about exhaust gases. So, what exactly does the city breathe and what does the smell of exhaust gases hide in itself?

Often, exhaust gases are called all emissions into the urban atmosphere, including boilers, factories and other industrial enterprises. In fact, it is correct to call this term only transport emissions that appear as a result of fuel processing. They are also called waste gases. Exhaust gases are a product of the operation of engines internal combustion, and, given the rapid growth in the number of transport over the past 50 years and, in particular, the increase in personal vehicles in cities, exhaust gases in the air of cities have settled in earnest and for a long time, and their number is only growing.

Now it is exhaust gases that are the main cause of air pollution in the city and constantly affect human health. So, we figured out the terminology, let's find out what exactly cars regularly deliver to our atmosphere, why it is dangerous and how to protect yourself if you smell exhaust gases in the apartment.

All cars emit carcinogens and toxic substances into the air. The composition of the exhaust gases of a car varies depending on the type of engine, gasoline or diesel, but the basic set remains the same.
So, the composition of automobile exhaust gases includes:

Component	Volume fraction in petrol engine, %	Volume fraction in diesel engine, %	Toxicity
Nitrogen	74–77	76–78	non-toxic
Oxygen	0,3–8	2–18	non-toxic
water vapor	3–5,5	0,5–4	non-toxic
Carbon dioxide	5–12	1–10	non-toxic
carbon monoxide	0,1–10	0,01–5	toxic
hydrocarbons	0,2–3	0,009–0,5	toxic
Aldehydes	0–2	0,001–0,009	toxic
Sulfur dioxide	0–0,002	0–0,03	toxic
Soot, g/m3	0–0,04	0,1–1,1	toxic
Benzopyrene, g/m3	0,01–0,02	0–0,01	toxic

As you can see, the composition of exhaust gases is quite diverse, and most of the components are toxic. Now let's see what effect exhaust gases have on a person.

The effect of exhaust gases on the human body

Vehicle exhaust fumes can be harmful to health, and quite serious. First of all, carbon monoxide or carbon monoxide, which we have already mentioned, has no taste and smell, but at high concentration it causes dizziness, headache, nausea, and can lead to fainting.
Sulphurous gasoline and the sulfur oxide it creates is one of the causes of strong exhaust odors. The fact is that sulfur dioxide molecules have a very noticeable effect on olfactory receptors, so this smell is felt even at a low concentration, and a more concentrated “aroma” covers all other smells for a person’s nose, which can be confirmed by anyone who lit matches in the house. Leaded gasoline enriches the air with lead. The amount of such exhaust gases and the health damage they cause has made lead one of the most notorious toxic compounds in the atmosphere. Currently, such gasoline is no longer used as a fuel for cars, but for quite a long time its vapors filled all major cities. Hydrocarbons in car emissions are oxidized when exposed to sunlight and form toxic compounds with a pungent odor, which particularly affect the upper respiratory tract and lead to exacerbations of chronic diseases of the respiratory system.
The harm from car exhaust gases is largely explained by carcinogens - soot and benzopyrene, which contribute to the development of tumors, especially malignant ones.

Considering exhaust gases and the harm they bring, we must add about the effect of this chemical cocktail in its entirety: prolonged contact with exhaust gases leads to death, in particular from carbon monoxide poisoning. The greatest danger of these emissions is their quantity, prevalence and fine particle size, which allows the exhaust to pass through the natural barriers of the body and into the lungs. With constant exposure to exhaust gases on the body, immunodeficiency, bronchitis can develop, brain vessels, the nervous system and other organs suffer. In addition, most of the toxic substances that make up exhaust gases can interact with each other and with other components of the atmosphere, which contributes to the formation of smog.

Everyone who has taken a school course in botany knows that plants also breathe. And, like any breathing organism, they feel pollution from exhaust gases on themselves. The smallest particles of harmful compounds enter the body of the plant and poison it, therefore, very often in the city, located near big roads or parking lots, lawns and trees look sluggish, quickly turn yellow or die altogether.

Air pollution from exhaust gases has significantly affected the composition of atmospheric precipitation. It is thanks to the activity of transport that acid rains, colored fogs or snow of fifty shades of black appear. Naturally, due to precipitation, the air is somewhat purified, but all the collected dirt enters the soil, causing general pollution environment with exhaust gases. The same compounds and heavy metals spread further through the soil, getting into animal feed and cultivated crops, which means polluting not only nature, but also repeatedly humans. Of course, it would be superfluous to panic about this, but with such pollution of the atmosphere with exhaust gases, you should take care of your health.

How to protect yourself from exhaust gases

We get the greatest harm from exhaust gases while in traffic jams, where there is simply nowhere to run from automobile emissions. In such a situation, if there is no respirator or gas mask at hand, you still have to inhale the exhaust, but you can cover your nose and mouth with a handkerchief or scarf. This will not completely protect you from exhaust emissions, but it will at least smooth the situation somewhat. With constant exposure to exhaust, it is worth diversifying your menu with antioxidants found in berries, fruits, green vegetables and green tea, as well as seeds, and drinking more water, as it promotes detoxification. Such “doping” helps the body cope with the consequences of inhaling a chemical cocktail and maintains health.

Exhaust gases in the apartment are clearly unwanted guests, but they often penetrate our homes if there are roads or parking lots under them or near them. If there is no possibility or desire to move to the bosom of nature away from the roads, you can create safe zones in the house. To understand how to protect yourself from exhaust gases in an apartment, you need to determine the source of their appearance. In the vast majority of cases, exhausts penetrate through windows. In this case, the best solution would be to install sealed double-glazed windows, and carry out ventilation using high-quality

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The effect of exhaust gases on the atmosphere is an urgent environmental problem. Many people use cars and do not even realize how badly they poison the air. To assess the damage, it is worth studying the composition of exhaust gases and the consequences of their impact on the environment.

What are exhaust gases made of?

Vehicle exhaust gases are produced during engine operation, as well as during incomplete or complete combustion used fuel. In total, over two hundred different components are found in them: some exist for only a few minutes, while others decompose for years and hover in the air for a long time.

Classification

All exhausts are divided into several groups according to their properties, constituent components and the degree of impact on the environment and the human body:

1. The first group includes all substances that do not have toxic properties. This includes water vapor as well as natural and integral components. atmospheric air, inevitably penetrating into automobile engines. This category also includes emissions of CO2 - carbon dioxide, which is also non-toxic, but reduces the concentration of oxygen in the air.
2. The second group of constituents of automotive exhaust gases includes carbon monoxide, ie carbon monoxide. It is a product of incomplete combustion of fuel and has pronounced toxic and toxic properties. This substance, getting into the human body by inhalation, penetrates into the blood and reacts with hemoglobin. As a result, the oxygen concentration is greatly reduced, hypoxia occurs, and in severe cases, death.
3. The third group covers nitrogen oxides, which have a brownish tint, an unpleasant pungent odor. Such substances are dangerous to humans, as they can irritate mucous membranes and affect the membranes. internal organs, especially the lungs.
4. The fourth group of exhaust gas components is the most numerous and includes hydrocarbons, which appear due to the incomplete combustion of the fuel used in automobile engines. And it is these substances that form bluish or light white smoke.
5. The fifth group of exhaust components is represented by aldehydes. The highest concentrations of these substances are observed at minimal loads or during the so-called idling, when the combustion temperature in the engine is not high.
6. The sixth group of exhaust components automotive gases are various dispersed particles, including soot. They are considered wear products of engine parts, and may also include oil particles, aerosols, carbon deposits. Soot itself is not dangerous, but it can settle in the respiratory tract and impair visibility from exhausts.
7. The seventh group of substances that make up the exhaust gases are various sulfur compounds formed during the combustion in engines of fuels containing sulfur (primarily diesel). Such components have a sharp characteristic odor, and they can irritate the mucous membranes, as well as disrupt metabolic processes and oxidative reactions.
8. The eighth group is different lead compounds. They appear during the operation of carburetor engines, subject to the use of leaded gasoline with additives that increase the octane number.

Consequences of exposure to exhaust gases

The impact of exhaust gases on human health, the environment and the atmosphere is extremely detrimental. First of all, the harmful emissions generated during the combustion of fuel in automobile engines greatly pollute the air, forming smog. Some small and light particles are able to rise and reach the atmospheric layers, changing their composition and compacting the structure.

Exhaust gases are one of the reasons greenhouse effect, which is developing at a rapid pace and poses a real threat to the environment and all of humanity. It causes weather anomalies, warming, melting glaciers, rising sea levels.

Another direction of the negative impact of exhaust gases is to contribute to the formation of acid rain. Recently, they began to go more and more often and greatly harm the ecosystem. Precipitation, which is highly acidic, changes the composition of the soil, which can make it unsuitable for growing plants and growing crops.

The flora suffers greatly: the rains literally corrode the foliage and fruits. Also, acid precipitation is harmful and dangerous to humans: they have an irritating and toxic effect on the skin, scalp.

The impact of car exhausts is extremely dangerous for the human body. Gas components almost immediately enter the respiratory system, irritate the mucous membranes of the lungs and bronchi, disrupt and inhibit respiratory function, and also cause whole line chronic diseases, including asthma and bronchitis. But substances from the respiratory tract are absorbed into the blood and change its composition, for example, significantly reduce the concentration of oxygen. Also, compounds penetrate into all tissues and organs, and some are capable of causing degeneration and mutation of cells in the future, their destruction.

How to avoid the serious effects of exhaust emissions

To minimize the dangerous and serious consequences of the negative effects of automotive exhaust gases, a number of measures should be taken:

1. Competent, rational and moderate operation of automobile Vehicle. Avoid prolonged work on Idling, avoid driving at high speeds, if possible, abandon the car in favor of using public transport, namely trolleybuses and trams.
2. The most efficient way is to move away from oily fuels and switch to alternative sources energy. In the past few years, scientists have begun to develop cars that run on electricity and even solar panels.
3. Constantly monitor the health of the car, and especially the condition of the engine and all its parts, as well as the operation of the exhaust system.
4. Modern concentration-reducing agents are available harmful substances in car exhaust. These include so-called exhaust gas catalytic converters. If you apply them constantly, then the emissions will be less dangerous for the atmosphere and humanity.

Using a car, each owner must take care not only about its serviceability, but also about the impact of transport and emissions on health and the environment. Only in this case will it be possible to avoid sad consequences.

Vehicle gases remain in the surface layer of the atmosphere, which makes it difficult to disperse them. Narrow streets and tall buildings also help trap toxic exhaust gases in the breathing zone of pedestrians. The composition of vehicle exhaust gases includes more than 200 components, while only a few of them are standardized (smoke, carbon and nitrogen oxides, hydrocarbons).[ ...]

The composition of exhaust gases depends on a number of factors: the type of engine (carburetor, diesel), its mode of operation and load, the technical condition and quality of the fuel (Tables 10.4, 10.5).[ ...]

Exhaust gases, in addition to hydrocarbons that make up the fuel, contain products of its incomplete combustion, such as acetylene, olefins and carbonyl compounds. The amount of VOCs in the exhaust gases depends on the operating conditions of the engine. Especially a large number of harmful impurities enter the ambient air when the engine is idling - during short stops and at intersections.[ ...]

Exhaust gases include such toxic substances as carbon monoxide, nitrogen oxides, sulfur dioxide, lead compounds and various carcinogenic hydrocarbons.[ ...]

The composition of the exhaust gases of carburetor and diesel engines includes about 200 chemical compounds, of which the most toxic oxides of carbon, nitrogen, hydrocarbons, including polycyclic aromatic hydrocarbons (benz (a) pyrene, etc.). When burning 1 liter of gasoline, 200-400 mg of lead, which is part of the anti-knock additive, enters the air. Transport is also a source of dust arising from the destruction of road surfaces and abrasion of tires.[ ...]

Since the composition of the exhaust gases depends on the mixture of fuel and air and the timing of ignition, it will also depend on the nature of driving. For achievement highest power mixtures with 10-15% enrichment are required, while the most economical is the speed with a slightly lower fuel enrichment. Most engines at idle require rich mixtures and combustion products are not completely ejected from the cylinder. When accelerating, the pressure in fuel system decreases and the fuel condenses on the collector walls. To prevent lean fuel mixture, a carburetor is used to supply more fuel when accelerating. Decreasing speed with a closed throttle increases the vacuum in the manifold, reduces air leakage and excessively saturates the mixture. With such fluctuations, emissions largely depend on the requirements for the engine (tab.[ ...]

Question about exhaust gases and aerosols released into the air automotive engines requires much more intensive study. In this direction, some data have already been obtained on the composition of exhaust gases, from which it follows that their composition changes under the influence of numerous factors, which include engine design, engine operation and maintenance, as well as the fuel used (Faith, 1954; Fitton, 1954) . An intensive study of the influence of all constituent parts exhaust gases in a chronic experiment, on animals.[ ...]

18

Colorless gas, odorless and tasteless. Density relative to air 0.967. Boiling point - 190°C. Solubility coefficient in water 0.2489 (20°), 0.02218 (30°), 0.02081 (38°), 0.02035 (40°). Weight of 1 liter of gas at 0°C and 760 mm Hg. Art. 1.25 g. Included in various gas mixtures, coke, shale, water, wood, blast-furnace gases, vehicle exhaust gases, etc.[ ...]

The exhaust gases of automobiles and other internal combustion engines are the main source of urban air pollution (up to 40% of all pollution in the United States). Many experts tend to consider the problem of air pollution as a problem of its pollution with exhaust gases of various engines (cars, motor boats and ships, jet engines aircraft, etc.). The composition of these gases is very complex, because, in addition to hydrocarbons various classes, they contain toxic inorganic substances (oxides of nitrogen, carbon, sulfur compounds, halogens), as well as metals and organometallic compounds. The analysis of such compositions containing inorganic and organic compounds with a wide range of boiling points (C1-C12 hydrocarbons) encounters significant difficulties, and, as a rule, several analytical methods are used for its implementation. In particular, carbon oxide and dioxide are determined by IR spectroscopy, nitrogen oxides by chemiluminescence, and gas chromatography is used to detect hydrocarbons. It can also be used to analyze inorganic components of exhaust gases, and the sensitivity of the determination is about 10-4% for CO, 10-2% for NO, 3-10-4% for CO2 and 2-10"5% for hydrocarbons, but the analysis complex and time-consuming.[ ...]

Exhaust gas concentrations in the tunnel are affected by: 1) intensity, composition and speed traffic flow; 2) length, configuration and depth of the tunnel; 3) the direction and speed of the prevailing winds in relation to the axis of the tunnel.[ ...]

In table. 12.1 shows the composition of the main impurities in the exhaust gases of gasoline and diesel internal combustion engines (ICE).[ ...]

It was mentioned above that the composition of the exhaust gases changes markedly with the change in the operating mode of the engine, so the reactor must be designed taking into account changes in concentrations. In addition, elevated temperatures are required for the reaction to proceed, so the reactor must provide a rapid rise in temperature, since water will condense in a cold reactor. Added to the technical difficulties necessary condition so that the reactor system operates for a long time without technical care. Unlike other devices in the car, in this case the motorist will not pay attention to the reactor system, which does not give him practical returns, and he may not receive real signals that the system has failed. In addition, monitor the effectiveness of the treatment system through regular checks and technical inspections much more difficult than achieving a certain average level of design reliability.[ ...]

10

The quantitative and qualitative composition of exhaust gases depends on the type and quality of fuel, type of engine, its characteristics, technical condition, qualifications of mechanics, provision of vehicle fleet with diagnostic equipment, etc.[ ...]

To determine nitrogen dioxide in the exhaust gases of internal combustion engines of automobiles and in the exhaust gases of silver regeneration baths, a non-flowing electrochemical cell with a long service life of 120 days is proposed. The working electrode is platinum or graphite, and the auxiliary is grade B coal. The absorption solution has a composition of 3% for KBr and 1% for H2304. The lower limit of the analyzed concentration of nitrogen dioxide by this stagnant cell is 0.001 mg/l.[ ...]

In table. 3 shows the approximate composition of the exhaust gases of carburetor and diesel engines (I. L. Varshavsky, 1969).[ ...]

Significant air pollution occurs exhaust! automobile gases. They include a large range of toxic substances, the main of which are: CO, NOx - hydrocarbons, carcinogens. The pollutants of the air basin from road transport should also include rubber dust formed as a result of abrasion of tires.[ ...]

The technical condition of the engine. The technical condition of the engine and, above all, the carburetor has a great influence on the composition of exhaust gases. Studies conducted by J-G. Manusadzhants (1971) showed that after the installation of new, properly adjusted carburetors on cars that previously had an increased content of carbon monoxide in exhaust gases (5-6%), the concentration of this gas decreased to 1.5% . Faulty carburetors after repair and adjustment also ensured a decrease in the content of carbon monoxide in the exhaust gases to 1.5-2%.[ ...]

A simple measure - adjusting engines can reduce the toxicity of exhaust gases by several times. Therefore, in the cities, control and measuring points are being created for diagnosing car engines. In a car fleet, on special running drums that replace the roadbed, the car passes a test, during which it is measured chemical composition engine gases under different operating conditions. A machine with a large exhaust emission to the line should not be produced. According to data available in the literature, this measure alone can reduce air pollution by 3.2 times in 1980, and by 4 times by 2000.[ ...]

In the scheme under consideration, a part of the thermal energy of exhaust gases during the heating period is used for heating purposes of the CS, adjacent settlements, greenhouses and livestock farms. The integrated power plant at the compressor station includes many units, assemblies and equipment shown in the diagram in Fig. 1, which have shown high efficiency and have been successfully operated for a long time in various industries.[ ...]

In the conditions of Yuzhno-Sakhalinsk, where the main pollutants are vehicle exhaust gases and waste from thermal power plants, special works on their impact on individual objects of the plant world has not been carried out. In the course of work to determine the microelement composition of a number of plants, including meadow and weed grasses, some observations were made on the content of toxic microelements in the above-ground mass of plants within the city and beyond, as well as on reclaimed waste maps of the ash dump of the Yuzhno-Sakhalinskaya CHPP . The chemical composition depends both on the species and on the external conditions existence, therefore, to determine lead, samples of the following plant species were taken: hedgehog (Dactylis glomerata L.), creeping clover (Trifolium repens L.), Langsdorf reed grass (Calamagrostis langsdorffii (Link) Trin.), bluegrass meadow (Poa pratensis L.) , pharmaceutical dandelion (Taraxacum officinale Web.) - within the city, on roadsides and for control - in places remote from anthropogenic impact.[ ...]

It has already been mentioned that the sun's rays can change the chemical composition of air pollutants. This is especially noticeable in the case of pollutants of the oxidizing type, when the sun's rays can lead to the formation of an irritating gas from a non-irritating one (Haagen-Smit a. Fox, 1954). Photochemical transformations of this type occur in the reaction between hydrocarbons contained in the air and nitrogen oxides, and the main source of both is the exhaust gases of cars. These photochemical reactions are of such great importance (for example, in Los Angeles) that great efforts are being made to solve this particular problem posed by automobile exhaust gases. The solution to this problem is approached from three different angles: a) by changing the fuel for engines; b) by changing the design of the engine; c) by changing the chemical composition of the exhaust gases after their formation in the engine.[ ...]

It may seem strange to you that there is no mention of carbon monoxide (carbon monoxide), which, as everyone knows, is part of the exhaust gases of a car. There are many people who die every year who have the habit of trying out an engine in a closed garage or lifting the windows of a car with a leak in its exhaust system. In high concentrations, carbon monoxide is certainly deadly: by combining with blood hemoglobin, it prevents the transfer of oxygen from the lungs to all organs of the body. But on outdoors in the vast majority of cases, the concentration of carbon monoxide is so low that it does not pose a danger to human health.[ ...]

It should be noted that a significant amount of carbon monoxide enters the atmospheric air with the exhaust gases of cars and other vehicles equipped with carbureted engines internal combustion, the exhaust of which contains CO from 2 to 10% (higher values ​​correspond to low speed modes) . Due to this Special attention is given to the development of carburetors, produced under the conditional name "Ozone" for passenger cars "Zhiguli". Thanks to a number technical innovations this carburetor can significantly reduce the emission of substances harmful to the human body into the atmosphere with exhaust gases. On the recommendation of the Central Scientific Research Automobile and Automotive Institute the carburetor uses the Cascade device, which optimizes the composition fuel-air mixture, thus making it possible not only to reduce the toxicity of emissions, but also to reduce the specific consumption of gasoline.[ ...]

Carbon monoxide is formed during the incomplete combustion of substances containing carbon. It is part of the gases released during the smelting and processing of ferrous and non-ferrous metals, exhaust gases of internal combustion engines, gases formed during blasting, etc.[ ...]

Modern methods of analysis allow, along with the age of individual ice layers, to determine the composition of the air during their formation, to monitor the growth of air pollution. So, in 1968 it was found that the level of lead oxide, which enters the air mainly with car exhaust gases, is already about 200 mg per 1 ton of ice. The authors of the book "Besieged eternal ice”, from which these figures are taken, comment on them as follows: “Ice, this silent witness to the evolution of the Earth’s climate, signals a huge danger. Will humanity listen to him? .[ ...]

Such studies also pave the way for the development of specific predictive models linking fuel composition and properties to exhaust emissions for vehicle families, starting with the earliest non-equipped vehicles. catalytic converters, up to cars latest models produced using the most the latest technologies. This relationship between properties, composition, and emissions is extremely complex, so such models allow fuel developers to find specific fuel composition limits where changes in fuel characteristics can have a measurable, quantifiable effect on exhaust emissions. These formulation limits will, of course, depend both on the type of vehicles available on the particular market and on the possibilities of fuel production. Thus, in this case, in order to understand the whole process, it is necessary to have a clear picture that characterizes both of these factors.[ ...]

Phenols are used for disinfection, as well as for the manufacture of adhesives and phenol-formaldehyde plastics. In addition, they are part of the exhaust gases of gasoline and diesel engines, are formed during the combustion and coking of wood and coal.[ ...]

Under the influence of emissions carried out by industrial enterprises, chemically active waste and residues from the main production, the composition of atmospheric air in cities changes significantly. It significantly increases the percentage of dust content, in addition, there are "traces" of substances that are not characteristic of the environment in its natural state. The increasing growth of vehicle exhaust gases contributes to the development of severe respiratory diseases. Emissions of harmful substances from vehicles and industrial enterprises cause increased air pollution with sulfur oxides, sulfates, carbon dioxide, carbon monoxide, nitrogen oxides, hydrogen sulfide, ammonia, acetone, formaldehyde, etc. The irritating effect of atmospheric pollution is manifested by a non-specific reaction of the body. In acute cases of high air pollution, irritation, conjunctiva, cough, increased salivation, spasm of the glottis and some other symptoms are noted. With chronic air pollution, there is a known variability of the listed symptoms and their less pronounced character. Air pollution in cities is the reason that increases the resistance to air flow in the respiratory tract.[ ...]

Control over the state of the air in the Federal Republic of Germany is carried out by a network of posts and nine permanent stations (Munich) that monitor the content of harmful gases and dust in the atmosphere. The measurement data are sent to a processing center equipped with a computer for compiling required characteristics air pollution and their ¡classification.[ ...]

Road transport is not one of the leading sources of sulfur dioxide in the atmosphere. In the book by I. L. Varshavsky, R. V. Malov “How to neutralize the exhaust gases of a car” (1968), the issue of sulfur dioxide as an emission from a car engine is not considered at all. This position is consistent with the results of studies in 1974-1975 of air on highways of a busy car traffic in Leningrad, where isolated cases of a slight excess of the permissible concentrations of sulfurous anhydride were observed (G. V. Novikov et al., 1975). However, according to the United States (VN Smelyakov, 1969), the annual emission of sulfur oxides by cars in this country reaches 1 million tons, i.e., it is commensurate with the emission of particulate matter. In England, in 1954, according to the data of Pchop (1956), the emission of sulfur dioxide by car engines amounted to 20 thousand tons. gasoline engines and 0.02% - diesel. These materials convince of the expediency of controlling anhydride concentrations on heavy traffic routes.[ ...]

In addition, this knowledge and this approach can be applied to newly developed engine technologies. As shown in fig. 1, it is expected that the future direction of work on minimizing emissions of conventional engines will shift towards the creation of fully optimized systems, while covering the vehicle, engine and fuel. A key factor in this process will be knowing how to properly formulate specific fuels to make them suitable for such systems.[ ...]

As examples of the practical application of promising Pb, Sn, and Te laser diodes, two projects developed by the American firm Texas Instruments (Dallas) can be cited. In the first of these, a compact device (weighing no more than 4.5 kg) based on a tunable laser diode is being developed for monitoring industrial emissions from pipes for the content of 302, NO2 and other gases. The second project is aimed at creating a convenient device for monitoring car exhaust gases for the content of CO, CO2, residues of unburned hydrocarbons and sulfur-containing gases. The constructed layouts are matrices of a number of laser bottoms, each tuned to a specific gas and optically connected by similar matrices of photodetectors. The instrument must be placed directly into the exhaust jet. Difficulties are associated with the development of a convenient cooler necessary to provide continuous laser radiation. This device is being created as a mass control tool in connection with the draft US state standard for the permissible composition of exhaust gases. Both devices are based on the absorption method.[ ...]

While fuel sulfur management and alternative fuel selection have the potential to provide indirect reductions in vehicle emissions, from the oil company's perspective, the main factor to consider when developing low-sulphur fuels is harmful emissions, is the possibility of direct influence on exhaust gas emissions of such fuel properties as hydrocarbon composition, volatility, density, cetane number etc., as well as oxygen-containing compounds (oxidizers) or biofuels included in the fuel. This section addresses the first question. The latter topic is discussed in more detail in the accompanying article published in the same journal.[ ...]

The nitrogen and sulfur cycles are increasingly affected by industrial air pollution. Nitrogen oxides (NO and N02) and sulfur oxides (50 g) appear during these cycles, but only as intermediate stages and are present in most habitats in very low concentrations. The burning of fossil fuels has greatly increased the content of volatile oxides in the air, especially in cities; at such a concentration, they already become dangerous for the biotic components of ecosystems. In 1966, these oxides accounted for about a third of the total (125 million tons) of industrial emissions in the United States. The main source of GOD is coal-fired thermal power plants, and the main source of NO2 is car motors. L), and nitrogen oxides are harmful, getting into the respiratory tract of higher animals and humans. As a result of chemical reactions of these gases with other pollutants, the harmful effect of both is aggravated (a kind of synergism is noted). The development of new types of internal combustion engines, the purification of fuel from sulfur and the transition from thermal to nuclear power plants will eliminate these serious disturbances in the nitrogen and sulfur cycles. Parenthetically, such changes in the way humans produce energy will raise other problems that need to be thought about in advance (see ch. 16).[ ...]

This circumstance predetermines the following argument in favor of domestic hydrogen energy. It consists in the need for a global approach to solving such problems. The trend towards the general integration of the trade and economic system today is such that it requires an analysis of the world market for the overwhelming range of goods and services. Under these conditions, Russia can no longer be pulled out of global industrial, trade and economic ties. It is impossible not to take into account, without incurring large material and moral losses, with increasingly stringent environmental requirements, enshrined in national and international legislation. The Clean Air Act adopted by the US Congress, the above-mentioned tightening on the chemical composition of exhaust gases from air and land vehicles in Western Europe and other regions of the planet, as well as a number of other legislative measures, essentially serve as the basis for the Global Environmental Code. There is a need to create a national concept for the use of hydrogen in fuel base countries as an environmentally friendly fuel for air and land transport. Such a concept and a corresponding national program can be developed as part of the conversion of defense industries.[ ...]

When studying environmental pollution with emissions from an industrial enterprise, only those chemicals are usually taken into account that, based on the technological process, can be considered priority in terms of gross emissions into the atmospheric air or into wastewater. Meanwhile, a significant part of the initial and final products of production has a fairly high reactivity. Therefore, there is reason to believe that these compounds interact not only at the stage of the technological process. The possibility of such interaction in the air cannot be ruled out. industrial premises, from where the newly formed products enter the atmospheric air as fugitive emissions. New chemicals can be produced as a result of chemical and photochemical reactions in polluted air, as well as in water and soil. An example is the formation of new chemicals from the products of incomplete combustion of fuel, which is part of the exhaust gases of cars. At present, the pathways of photochemical oxidation of these products have been sufficiently studied. The possibility of atmospheric air pollution by qualitatively new chemicals not specified in the technological regulations of the enterprises under study has been proved.

According to environmental studies, in large cities, almost 90% of air pollution comes from transport emissions. The biggest pollutants are diesel-powered vehicles. The type of gasoline burned also plays an important role. For example, sulphurous gasoline emits sulfur oxides into the atmosphere, and chlorine, bromine and lead. But the most common exhaust gas composition is as follows:

Nitrogen - 75%;
- oxygen - 0.3-8.0%;
- water - 3-5%;
- carbon dioxide - 0-16%;
- carbon monoxide - 0.1-5.0%;
- nitrogen oxides - 0.8%;
- hydrocarbons - 0.1-2.5%;
- aldehydes - up to 0.2%;
- soot - up to 0.04%;
- benzpyrene - 0.0005%.

Carbon monoxide

Product of incomplete combustion of gasoline or diesel fuel. This gas has no color, so a person cannot feel its presence in the atmosphere. This is its main danger. Carbon monoxide binds to hemoglobin and causes tissues and organs in the body. This leads to headache, dizziness, loss of consciousness and even death.

There are frequent cases when warming up the car in a closed or even open garage led to the death of the car owner. Odorless and colorless, carbon monoxide causes loss of consciousness and death.

nitrogen dioxide

Yellowish-brown gas with a pungent odor. It impairs visibility, gives the air a brownish tint. Very toxic, can cause bronchitis, significantly reduces the body's resistance to colds. Nitrogen dioxide has a particularly negative effect on people suffering from chronic respiratory diseases.

hydrocarbons

In the presence of nitrogen oxides and under the influence of ultraviolet radiation from the sun, hydrocarbons are oxidized, after which they form oxygen-containing toxic substances with a pungent smell, the so-called photochemical smog. Cyclic aromatic hydrocarbons are also found in tars and soot, they are the strongest carcinogens. Some of them are capable of causing mutations.

Formaldehyde

A colorless gas with an unpleasant and pungent odour. In large quantities, it irritates the respiratory tract and eyes. It is toxic, causes damage to the nervous system, has a mutagenic, allergenic and carcinogenic effect.

Dust and soot

Suspended particles, no larger than 10 microns. Can cause diseases of the respiratory system and mucous membranes. Soot is a carcinogen and can cause cancer.

During engine operation, unburned particles accumulate on the walls of the exhaust system. Under the influence of gas pressure, they are released into the atmosphere, polluting it.

Benzpyrene 3.4

One of the most hazardous substances which contains exhaust gases. It is a strong carcinogen, increases the likelihood of cancer.

As a result of the operation of the internal combustion engine, which is equipped with each modern car, hydrocarbon fuels are burned, and a huge amount of various chemical compounds are released into the atmosphere. Since the mid-1960s, exhaust emissions have become a concern for many people. From this moment begins the struggle of mankind for the maximum possible reduction of these emissions.

The problem with the greenhouse effect

Climate change at the global level is one of the important features of the 21st century. In many ways, these changes are due to the activities of mankind, in particular, greenhouse gas emissions into the atmosphere have increased significantly in recent decades. The main source of emissions are vehicle exhaust gases, 30% of which are greenhouse gases.

Greenhouse gases exist naturally and are designed to regulate the temperature of our blue planet, but even a slight increase in their amount in the atmosphere can lead to serious global consequences.

The most dangerous greenhouse gas is CO2, or carbon dioxide. It accounts for about 80% of all emissions, most of which is associated with the combustion of fuel in car engines. Carbon dioxide remains active in the atmosphere for a long time, which increases its danger.

The car is the main air pollutant

One of the main sources of carbon dioxide is car exhaust. In addition to CO2, they emit carbon monoxide CO, hydrocarbon residues, nitrogen oxides, sulfur and lead compounds, and particulate matter. All of these compounds enter the air in huge quantities, leading to a global increase in temperature and the emergence of serious diseases in people living in large cities.

In addition, different vehicles emit different compositions of exhaust gases, depending on the type of fuel used, such as gasoline or diesel fuel. So, when gasoline is burned, a whole bunch of chemical compounds appear, which consist mainly of carbon monoxide, nitrogen oxides, hydrocarbons and lead compounds. Diesel engine exhaust contains soot, which causes smog, unburned hydrocarbons, nitrogen oxides and sulfuric anhydride.

Thus, the harm of exhaust gases to the environment is undeniable. Work is currently underway to reduce the amount of emissions from each car, as well as replacing the use of gasoline with alternative and more environmentally friendly energy sources, such as solar or wind energy. great attention given hydrogen fuel, the result of combustion of which is ordinary water vapor.

Impact of emissions on human health

The harm that exhaust gases cause to human health can be very serious.

First of all, carbon monoxide is dangerous, which causes loss of consciousness and even death if its concentration in the atmosphere is increased. In addition to it, sulfur oxides and lead compounds are harmful, which fly out in large quantities from exhaust pipe auto. Sulfur and lead are known to be highly toxic and can remain in the body for a long time.

Hydrocarbons and soot particles, which also enter the atmosphere as a result of partial combustion of fuel in the engine, can cause severe diseases of the respiratory system, including the development of malignant tumors.

The constant and prolonged effect of exhaust gases on the body leads to a weakening of human immunity, bronchitis. Damage is done to blood vessels and the nervous system.

Vehicle exhaust

Currently, in all countries of the world, cars are subject to mandatory checks for compliance with established standards. environmental standards. In most cases, the following exhaust gases are called, the environmental damage from which is maximum:

• carbon monoxide and carbon dioxide;
• various hydrocarbon residues.

However modern standards The developed countries of the world also impose requirements on the level of nitrogen oxides emitted into the atmosphere and on the system for monitoring the process of fuel evaporation from the fuel tank.

Carbon Dioxide (CO)

Of all the environmental pollutants, carbon dioxide is the most dangerous because it has neither color nor smell. Harm to the health of car exhaust gas is significant, for example, its concentration in the air of only 0.5% can cause a person to lose consciousness and subsequent death within 10-15 minutes, and such a concentration as 0.04% leads to a headache .

This product of the internal combustion engine is formed in large quantities when the gasoline mixture is rich in hydrocarbons and poor in oxygen. In this case, incomplete combustion of the fuel occurs and CO is formed. The problem can be solved by correct setting carburetor, replacing or cleaning a dirty air filter, adjusting injection valves combustible mixture, and some other measure.

A large amount of CO is released in the exhaust gases during the warm-up process of the car, because its engine is cold and partially burns the gasoline mixture. Therefore, warming up the car should be carried out in a well-ventilated area or in the open air.

Hydrocarbons and organic oils

Hydrocarbons that do not burn out in the engine, as well as evaporated organic oils are substances that determine the main harm of car exhaust gases to the environment. By themselves, these chemical compounds do not pose a danger, however, getting into the atmosphere, they react with other substances under the influence of sunlight, and the resulting compounds cause pain in the eyes, making it difficult to breathe. In addition, hydrocarbons are the main cause of smog in large cities.

Reducing the amount of hydrocarbons in the exhaust gases is achieved by tuning the carburetor so that it cooks both lean and rich mixture, as well as constant monitoring of the reliability of compression rings in the engine cylinders and adjustment of spark plugs. Complete combustion of hydrocarbons leads to the formation of carbon dioxide and water vapor, which are harmless substances both for the environment and for humans.

nitrogen oxides

About 78% of atmospheric air consists of nitrogen. It is a fairly inert gas, but at fuel combustion temperatures above 1300 ° C, nitrogen splits into individual atoms and reacts with oxygen, forming various types oxides.

The harmful effects of exhaust gases on human health are also associated with these oxides. In particular, the respiratory system suffers the most. At high concentrations and prolonged action, nitric oxides can cause headaches and acute bronchitis. Oxides are also harmful to the environment. Once in the atmosphere, they form smog and destroy the ozone layer.

To reduce emissions of nitrogen oxides, a special gas emission recirculation system is used in cars, the principle of which is to maintain the engine temperature below the threshold for the formation of these oxides.

Fuel evaporation

The mere evaporation of fuel from a tank can be one of the major sources of environmental pollution. In this regard, over the past few decades, special tanks have been manufactured, the design of which is designed to solve this problem.

The fuel tank must also "breathe". Designed for this special system, which lies in the fact that the tank cavity itself is connected by means of hoses to a tank filled with activated carbon. This coal is able to absorb the resulting fuel vapors when the car engine is not running. As soon as the engine is started, the corresponding hole opens and the vapors absorbed by the coal enter the engine for combustion.

The performance of this entire system from the tank and hoses must be constantly monitored, since they may leak fuel vapors that will pollute the environment.

Solving the problem of emissions in large cities

Tens of thousands of factories are concentrated in large modern cities, millions of people live and hundreds of thousands of cars drive along the streets. All this greatly pollutes the atmosphere, which has become the main problem of the 21st century. To solve it, the city authorities introduce a number of administrative and measures.

So, in 2003, a protocol against pollution by road transport of the environment was adopted in London. Under this protocol, drivers who drive through the central areas of the city are charged additional fee in the amount of £10. In 2008, the London authorities approved a new law that began to more effectively regulate the movement of freight transport, buses and personal cars in the central part of the city, setting an upper speed threshold for them. These measures led to a reduction in the content of harmful gases in the atmosphere over London by 12%.

Since the 2000s, similar measures have been taken in many million-plus cities. Among them are the following:

• Tokyo;
• Berlin;
• Athens;
• Madrid;
• Paris;
• Stockholm;
• Brussels and others.

The opposite effect of the anti-pollution law

The fight against car exhaust is not an easy task, which is clearly demonstrated by the example of two of the most polluted cities on the planet: Mexico City and Beijing.

Since 1989, the capital of Mexico has a law that prohibits the use of a private car on certain days of the week. At first, this law began to bring positive results and gas emissions decreased, but after a while, residents began to purchase second used cars, thanks to which they began to drive every day. personal transport, replacing one car with another within a week. This situation worsened the state of the urban atmosphere even more.

A similar situation is observed in the capital of China. According to 2015 data, about 80% of Beijing residents have several cars, allowing them to travel every day on them. In addition, a huge number of violations of the anti-pollution law are recorded in this metropolis.