Electric power plants, atmospheric sulfur

Petroleum fueled electrical power plants are also a major contributor to air pollution. Such power plants emit about 500 tons per day of sulfur into the environment in the form of sulfuric anhydride. This reacts with water resulting in the immediate formation of sulfuric acid. A French journalist, M. Ruze, has presented data to show that a French thermal power plant belonging to Electricite de France emits about 33 tons of sulfuric anhydride into the atmosphere on a daily basis. This can result in a daily production of about 50 tons of sulfuric acid. The after-math of acid production is acid rain, the adverse effect of which covers the power plant and surrounding territory up to a radius of 5 km. Such rains have high chemical activity. They corrode even cement and marble. 

Because fossil fuels are the remains of once-living organisms, fuels like coal contain sulfur. In electrical power plants, sulfur burns along with the carbon in coal, forming sulfur dioxide (SO ). There also is some sulfur in gasoline, so motor vehicles are also a source of SO3 (not SO2 because catalytic converters convert SO into SO3). Sulfur dioxide and trioxide are both noxious gases (see the section in chapter 3 titled The NO Problem ) and two of the main components of so-called London smog. Oxides of sulfur cause respiratory disease and contribute to the formation of haze that reduces atmospheric visibility. 

Certain pollutants—such as NO, NO2, and SO2— form acids when mixed with water. NO and NO2, primarily emitted in vehicular exhaust, combine with atmospheric oxygen and water to form nitric acid, HN03(a ). SO2, emitted primarily from coal-powered electricity generation, combines with atmospheric oxygen and water to form sulfuric acid, 112804(0(7). Both HN03(o ) and 112804(0 ) result in acidic rainwater. The problem is greatest in the northeastern United 8tates where pollutants from midwestern electrical power plants combine with rainwater to produce rain that is up to ten times more acidic than normal. 

The best way to prevent these problems is to prevent acid rain at the start. Reducing emissions from automobiles and power plants would help reduce acid-rain levels. This means conserving energy and driving less. The less energy people use, the less coal needs to be burned to produce electricity. These measures help decrease the sulfur and nitrogen oxides in the atmosphere and, therefore, decrease the amount of acid rain. 

Coal is burned in many of the world s power plants to generate electricity. Significant air pollution is produced if the stack gases from coal-fired furnaces are not treated before being released to the atmosphere. Untreated gases contain soot (fine unburned carbon particles), nitrogen oxides (NO.x), ash, and sulfur dioxide (SO2). 

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