- September 11, 2012
- Posted by: essay
- Category: Free essays
The problem of air pollution is one of the actual problems of the humanity since ancient times. Then people had polluted the air with smoking, burning fires etc. Since that time, the level of pollution has significantly increased: now the atmosphere receives tons of chemicals every day. For a certain time the pollution was not very visible and did not influence peoples’ lives much because the Earth can absorb and dissolve pollutants; however, the resources of the planet are not endless. Currently pollution problems have become a very significant trouble for all countries, and air pollution is one of the most urgent of them.
Taking into account the fact that an ordinary person inhales about 20000 liters of air every day, we can make a conclusion hat air pollution is one of the factors that strongly influence people’s health. In addition to that, pollution can destroy the balance of ecosystems and affect natural circulation of substances. The aim of this essay is to analyze main substances that cause air pollution and their chemistry and discuss possible ways of using alternative fuels on order to avoid pollution and to make fuel usage more efficient.
1. Air pollutants
What is classified as ďair pollutionĒĚ? It is high concentration of some substances in the atmosphere which can cause harm or produce undesirable effects upon living organisms. Air pollutants can be any essences: solids, liquids or gases; also, pollution area may vary from local (small areas) to regional and even global one (worldwide). The air itself consists of 78% of nitrogen, 21% of oxygen, 1% of argon and 0,03% of carbonic acid (Air & Waste Management Association 25). Actually, any of these gases in excess concentration may be regarded as pollutant one, as well as any other substances in sufficient concentration may be harmful.
Main pollutants are sulfur oxides, monoxide of carbon, nitrogen oxides, volatile organic compounds and different particulates.¬† The molecules of such substances are shown on Figure 1.
Figure 1. Pollutants (Vallero, 252)
Let us regard the main sources of pollutants and principal chemical reactions resulting in air pollution. For monoxide of carbon the main sources are incomplete combustion of methane and the combustion of fossil fuels (Martin-Duque and Brebbia 114).
(combustion of fossil fuels)
Also, fossil fuels combustion lead to appearing of particulates in the atmosphere (dust, sand, smoke, pollen, ash etc.). ¬†Car engines in the process of combustion also produce oxides of nitrogen:
As for sulfur oxides, they appear due to coal combustion:
Sulfur oxides can also be emitted by volcanoes:
Volatile organic compounds appear because of fuels which can be burnt only partially such as gasoline and others; these components are also emitted by plants; the use of souvenirs, paints and some kinds of cosmetic products also leads to emitting volatile organic compounds into the atmosphere (Seinfield and Pandis 410).
Effects of the pollutants can be various: they can contaminate soil and water, reduce plant health and productivity, and destroy ecosystemsĒ¶ Unpleasant effects can be witnessed on human health: pollutants irritate respiratory system and cause corresponding illnesses; they can also be absorbed into the blood and cause a chemical chain reaction for the whole organism. Ozone and other pollutants may damage lung fissure and reduce lung function. In general, the health of an average human being has been significantly weakened due to pollution effects.
2. Alternative fuels
Though there are no commercially available vehicles and other equipment working on alternative fuels, a lot of research has been done in this direction. Main kinds of alternative fuels available today are the following: liquid petroleum gas, compressed natural gas, liquefied natural gas, methanol, ethanol, biodiesel, electrical fueling and hydrogen (Poulton 38).
The aim of this essay is to analyze the chemistry of alternative fuels. Molecules of such fuels are usually small and simple, as it is shown for methane (), the constituent of liquefied and compressed natural gas, propane – ¬†(Sunqqyu 67).
Methane¬†¬†¬†¬†¬†¬†¬†¬†¬† Propane¬†¬†¬†¬†¬†¬†¬† Isooctane
Figure 2. Molecules of alternative fuels containing hydrogen
For more complex alternative fuels (for example, methanol and ethanol, aimed to replace hydrocarbons) and contain oxygen atoms. Figure 3 illustrates this situation.
Figure 3. Molecules of alternative fuels containing hydrogen and oxygen
As for implementation of these fuels, it might appear very efficient to use hydrogen for drivetrains; also, electric vehicles powered with batteries may be used. This leads in carbon dioxide reduction, and the power necessary for splitting up molecules of hydrogen can be taken from renewable sources of energy such as energy of sun and wind.
The critical situation with air pollution has to be resolved with the invention and introduction of alternative fuels which have low percent of sulfur and carbon. Using alternative fuels may not only solve the situation concerning air pollution, but also result in better economical efficiency compared to traditional fuels. However, current measures taken by the governments in order to stop air pollution are not highly effective; the two necessary things to be done are the research for new, more effective alternative fuels (and in general, the methods of improving efficiency of energy usage) and methods of cleaning up the polluted area as well as output control methods should be developed in order to reduce pollution and to diminish the influence of polluting factors.