Almost all of the electricity that powers modern life comes from burning fossil fuels such as coal, natural gas, and oil. Acid deposition is caused by two pollutants that are released into the atmosphere when fossil fuels are burned: sulfur dioxide (SO2) and nitrogen oxides (NOx). Coal accounts for most U.S. SO2 emissions and a large portion of NOx emissions. Sulfur is present in coal as an impurity, and it reacts with air when the coal is burned to form SO2. In contrast, NOx is formed when any fossil fuel is burned.
There are several options for reducing SO2 emissions, including using coal containing less sulfur, washing the coal, and using devices called “scrubbers” to chemically remove the SO2 from the gases leaving the smokestack. Power plants can also switch fuels—for example, burning natural gas creates much less SO2 than burning coal. Certain approaches will also have the additional benefit of reducing other pollutants such as mercury and carbon dioxide (CO2). Understanding these “co-benefits” has become important in seeking cost-effective air pollution reduction strategies. Finally, power plants can use technologies that do not burn fossil fuels. Each of these options, however, has its own costs and benefits; there is no single universal solution.
Similar to scrubbers on power plants, catalytic converters reduce NOx emissions from cars. These devices have been required for over 20 years in the United States, and it is important to keep them working properly. Recently, tailpipe restrictions were tightened to help curb NOx emissions. EPA also continues to make, changes to gasoline that allow it to burn cleaner.
Almost all of the electricity that powers modern life comes from burning fossil fuels such as coal, natural gas, and oil. Acid deposition is caused by two pollutants that are released into the atmosphere when fossil fuels are burned: sulfur dioxide (SO2) and nitrogen oxides (NOx). Coal accounts for most U.S. SO2 emissions and a large portion of NOx emissions. Sulfur is present in coal as an impurity, and it reacts with air when the coal is burned to form SO2. In contrast, NOx is formed when any fossil fuel is burned.There are several options for reducing SO2 emissions, including using coal containing less sulfur, washing the coal, and using devices called “scrubbers” to chemically remove the SO2 from the gases leaving the smokestack. Power plants can also switch fuels—for example, burning natural gas creates much less SO2 than burning coal. Certain approaches will also have the additional benefit of reducing other pollutants such as mercury and carbon dioxide (CO2). Understanding these “co-benefits” has become important in seeking cost-effective air pollution reduction strategies. Finally, power plants can use technologies that do not burn fossil fuels. Each of these options, however, has its own costs and benefits; there is no single universal solution.Similar to scrubbers on power plants, catalytic converters reduce NOx emissions from cars. These devices have been required for over 20 years in the United States, and it is important to keep them working properly. Recently, tailpipe restrictions were tightened to help curb NOx emissions. EPA also continues to make, changes to gasoline that allow it to burn cleaner.
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