Automobile emission effect on the environment

Modern internal combustion engine working principles have been considered in this article, as well as the composition of exhaust gases, being emitted by this type of automobile engine. Toxic and carcinogenic products of fuel combustion negative impact on the human organism and the environment has been theoretically studied. Existing solutions of the current issue have been identified.

Key words: cars, exhaust gases, internal combustion engine, gasoline, diesel, emissions, toxic compounds, environment .

Introduction

Modern human life is difficult to picture without cars. Comfort, fast transportation and almost any type of cargo delivery on the scale of districts, cities, and even continents are well-grounded reasons for constant and widely-spread utilization of vehicles. According to the statistics [1], approximately 66 million light and heavy vehicles were sold in the world in 2005, and, for comparison, in 2019 the rate was increased to 91 million automobiles. The overall number of functioning cars is rather difficult to estimate because of the specific registration regulations in different countries. 1,4 billion — is the most frequently mentioned number in the internet sources. Nonetheless, despite all the advantages being provided cars do considerable damage to our planet. Enormous water, energy, and resources expenditures for manufacturing as well as a growing number of accidents every year are substantial motives for reconsidering automobiles’ unconscious usage. Beyond that, engine pollution is worth mentioning. Compounds being emitted by engines to the environment are a serious threat to both people and the world ecological system.

Problem statement

The main purpose of this research is a theoretical studying of exhaust gases composition and its effect on the Omsk region environment. The aims of the current study are:

− Brief internal combustion engines performance study;

− Study of the compounds, produced by automobile engine;

− Detection of negative consequences of pollution, caused by engines;

− Existing solutions identification.

There are several types of engines applied in automotive industry, the most popular of which are internal combustion engine (ICE). On its turn, such type of engines currently in production is subdivided into the spark ignition gasoline engine and the compression ignition diesel engine. Most of these are four-stroke cycle engines, which means that four piston strokes are needed to complete a cycle. The cycle involves four separate processes: intake, compression, combustion and power stroke, and exhaust [2]. Chemical energy, generated by fuel and air mixture combustion, eventually transforms into crankshaft rotating work, which subsequently leads to wheels driving.

The most significant part of the cycle, setting the car in motion, is the chemical reaction of fuel burning. Modern vehicles run on different types of fuels, including gasoline, diesel, liquified petroleum (propane), compressed natural gas, ethanol, and biodiesel [3]. According to the data, obeyed by the analytical agency “AUTOSTAT” in 2018, approximately 84 % of car owners in Russia preferred gasoline, other 10 % used diesel, and about 6 % — liquified petroleum (propane), compressed natural gas, ethanol and biodiesel [4].

The most in-demand fuels — gasoline and diesel — generally contain such hydrocarbons as paraffins, naphthenes, and aromatics in different proportions, with the addition of special octane number increasing components. Total combustion of these compounds produces non-toxic carbon dioxide, oxygen, nitrogen, and water normally. But under actual operating conditions including engine peculiarities, post-combustion catalyst efficiency, fuel purification extent, and air temperature, toxic substances emit as well. The average Chemical composition of car exhaust is displayed in table 1.

Table 1

Chemical composition of car exhaust [5]

Let's take a closer look at each of the toxic and carcinogenic components. Carbon monoxide (CO) — is a colorless, odorless, and tasteless flammable gas that is slightly less dense than air, an intermediate in the oxidation of carbon compounds to carbon dioxide. CO poisoning symptoms commonly comprise headache, dizziness, weakness, vomiting, chest pain, and confusion. Large exposures can result in loss of consciousness, arrhythmias, seizures, or death. Long term complications may include feeling tired, trouble with memory, and movement problems. With regard to the environmental consequences, carbon monoxide is a weak direct greenhouse gas, but has important indirect effects on global warming. It reacts with hydroxyl (OH) radicals in the atmosphere, diminishing their abundance. As OH radicals help to reduce the lifetimes of strong greenhouse gases, like methane, carbon monoxide indirectly increases the global warming potential of these gases [5].

Hydrocarbons emitted by engines contain approximately 200 aliphatic and aromatic compounds, that have a narcotic effect on the central nervous system, can cause chronic diseases, and some aromatics have toxic properties. Olefins and nitrogen oxides conjointly actively contribute to the formation of smog under certain meteorological conditions.

Aldehydes RCHO are the products of incomplete combustion, formed in the early stages of oxidation of fuel hydrocarbons. Low molecular weight aldehydes — formaldehyde НСНО and acrolein СН3СНО prevail among them. Negative impact includes narcotic effect, dermatitis, burns of the mucous membrane, nausea, asthma, dizziness and death. Even low concentrations are ruinous to all living creatures.

Nitrogen oxides (NO, NO2) severely irritate the lining of eyes, in high concentrations (over 0.004 %) — cause asthmatic manifestations, and pulmonary edema. Reacting with the atmospheric water, they also make a contribution to the formation of acid rains.

Sulfur dioxide is a noxious colorless gas, having an irritating effect on the mucous membranes of the throat, nose, eyes, in high concentrations cancer-causing. Inhalation of humid air containing sulfur oxide is especially dangerous for people with cardiovascular disease. Long-term inhalation of sulfur dioxide acts on the body especially toxic, disrupting the nervous system.

Benzopyrene (C20H12) is a first hazard class polyaromatic compound, one of the most potent and widespread carcinogens. This substance is able to penetrate the organism through the skin, respiratory organs, gastrointestinal tract, placenta. In addition to carcinogenic, benzopyrene has mutagenic, embryotoxic, and hematotoxic effects.

Research results

The following results of this study were obtained:

1. Chemical compounds pollution, caused by automobile engine operation, is an urgent problem of constant control and the search for a solution.
2. Automobile exhaust gases contain not only non-toxic products of full combustion, such as water and carbon dioxide but a considerable quantity of toxic and carcinogenic substances including carbon monoxide, soot, benzopyrene, nitrogen and sulphur oxides.
3. Complete combustion toxic products disrupt the normal functioning of the human organism by affecting all its organs, they cause negative consequences for the environment as well.
4. Cardiovascular and pulmonary systems are the most vulnerable parts of the human organism to the action of harmful components of exhaust fumes. Car air pollution elevates the risk of death from cardiopulmonary and non-allergic respiratory diseases.

Conclusions

Exhaust gas pollution issue has been of great importance since the first car was invented. Humanity is constantly searching for a solution by improving current technologies and creating new ones. Due to the technological progress and policies designed to tackle climate change, emissions of CO and other car pollutants have been significantly reduced in recent years. The most extensively applied methods are:

1. Fuels and emission standards introduction (the qualitative composition of the manufactured and sold fuel control — in Russia these are fuel standards, regional requirements, in Europe — EURO standards).
2. Increased rates of the transport tax on the car engine power imposition.
3. Ecologically friendly fuel types utilization (liquified petroleum (propane), compressed natural gas, ethanol and biodiesel).
4. Border vegetation zone creation in aim of diminishing exhaust pollution (One tree absorbs the amount of exhaust gases emitted by an average car for 25,000 km per year).
5. Engines and vehicles continual development.
6. Utilization of automotive catalytic converter (device in the exhaust system designed to reduce the toxicity of exhaust gases by means of nitrogen oxides reduction and using the resulting oxygen to burn carbon monoxide and unburned hydrocarbons).

References:

1. International Organization of Motor Vehicle Manufacturers/ 2005–2019 SALES STATISTICS [digital source], URL: http://www.oica.net/category/sales-statistics/ (reference date 19.10.2020)
2. Office of energy efficiency & renewable energy / Internal Combustion Engine Basics [digital source], URL: https://www.energy.gov/eere/vehicles/articles/internal-combustion-engine-basics#:~:text=There %20are %20two %20kinds %20of,needed %20to %20complete %20a %20cycle. (reference date 20.10.2020)
3. CarBibles / 6 types of fuel for your car [digital source], URL: https://www.carbibles.com/types-of-car-fuel/#:~:text=Gasoline,fuel %20for %20most %20car %2Dtypes (reference date 20.10.2020)
4. Автостат. Аналитическое агентство / Какой тип топлива используют россияне для заправки автомобилей? [digital source], URL: https://www.autostat.ru/infographics/35811/ (reference date 21.10.2020)
5. Колбасина Н. И., Котов М. М. Химический состав выхлопных газов автотранспорта, его влияние на здоровье человека // Материалы X Международной студенческой научной конференции «Студенческий научный форум» URL: http://scienceforum.ru/2018/article/2018004431 (reference date: 28.10.2020).
6. Green House Gases / Other Indirect Greenhouse Gases — Carbon monoxide [digital source], URL: http://www.ghgonline.org/otherco.htm#:~:text=Carbon %20monoxide %20(CO) %20is %20only,the %20atmosphere %2C %20reducing %20their %20abundance.&text=However %2C %20a %20small %20but %20significant,through %20deposition %20on %20the %20ground (reference date 28.10.2020)