Harmful effects of coal burning

Date: 2015-10-07; view: 478.

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Combustion of coal, like any other compound containing carbon, produces carbon dioxide (CO₂) and nitrogen oxides (NO_x) along with varying amounts of sulfur dioxide (SO₂) depending on where it was mined. Sulfur dioxide reacts with oxygen to form sulfur trioxide (SO₃), which then reacts with water to form sulfuric acid. The sulfuric acid is returned to the Earth as acid rain.

Emissions from coal-fired power plants represent the largest source of carbon dioxide emissions, a primary cause of global warming. Coal mining and abandoned mines also emit methane, another cause of global warming. Since the carbon content of coal is much higher than oil, burning coal is a more serious threat to global temperatures. Many other pollutants are present in coal power station emissions. A study commissioned by environmental groups claims that coal power plant emissions are responsible for tens of thousands of premature deaths annually in the United States alone. Modern power plants utilize a variety of techniques to limit the harmfulness of their waste products and improve the efficiency of burning, though these techniques are not subject to standard testing or regulation in the U.S. and are not widely implemented in some countries, as they add to the capital cost of the power plant. To eliminate CO₂ emissions from coal plants, carbon capture and storage has been proposed but has yet to be commercially used.

Coal and coal waste products including fly ash, bottom ash, boiler slag, and flue gas desulferization contain many heavy metals, including arsenic, lead, mercury, nickel, vanadium, beryllium, cadmium, barium, chromium, copper, molybdenum, zinc, selenium and radium, which are dangerous if released into the environment. Coal also contains low levels of uranium, thorium, and other naturally-occurring radioactive isotopes whose release into the environment may lead to radioactive contamination. While these substances are trace impurities, enough coal is burned that significant amounts of these substances are released, paradoxically resulting in more radioactive waste than nuclear power plants.

Due to its scientifically accepted connection with climate change , the world's reliance on coal as an energy source, and health concerns in areas with poor air pollution controls, The Economist recently labeled the burning of coal "Environmental Enemy No. 1."