Fossil fuels—coal, oil, and natural gas—are America’s primary source of energy. America’s annual consumption of fossil fuels grown rapidly. 89 % of these consumption are consumed by boilers, transportation, residential usage, fuels for direct heating of process. The balance is used for feed-stocks, raw materials, and other miscellaneous uses. And most of the dirty fuels such as coal and residual oil go into boilers.
Fuel burned are by far the largest single source of air pollution. This pollution is from sulfur oxide. It is also a significant source of particulate matter and nitrogen oxides. Boiler combustion is sufficiently important to warrant the effort to analyze the complete nature of the problems.
Fuel consumption in boilers is divided into three sectors: utility boilers producing steam for generation of electricity which is actually consuming probably 59%, industrial boilers producing steam or hot water for process heat,generation of electricity or space heat consuming about 24%, and boilers for space heating for commercial and institutional facilities consuming the 17%.
The fuels consumed by boilers in large quantities are natural gas, distillate oil, and coal. Additional energy is derived from the burning of waste such as bark, bagasse, liquid hydrocarbon waste materials, etc. These said fuels contribute only a small percent to energy requirements. But they may however present environmental problems. Although problems have not been address due to the fact that these problems are not full understood. New Sources performance Standards for burning boilers waste are to be developed in the near future.
For fossil fuels, various combination of consuming sectors and type of fuel, have independent significant and insignificant environmental consequences. Boilers have three different types, the atertube, firetube and cast iron therefore to determine the overall pollution due to boilers are hard to determine and complicated. In addition each type varies in type and application and other factors influencing the character and quantity of environmental discharges.
Due to the complexity of analyzing the impacts of boiler operation in the United States, U.S Environmental Protection Agency has given rise to a series of studies. These studies pave the way for a better understanding of the impacts of boilers in our environment and the development of ways to control specific pollutants.
Many of the environmental problems our country faces today result from our fossil fuel dependence. These impacts include global warming, air quality deterioration, oil spills, and acid rain.
Air pollution is one major effect of fuels. Several important pollutants are produced by fossil fuel combustion: carbon monoxide, nitrogen oxides, sulfur oxides, and hydrocarbons. In addition, total suspended particulates contribute to air pollution, and nitrogen oxides and hydrocarbons can combine in the atmosphere to form tropospheric ozone, the major constituent of smog. This is just one of the effects; there is water and land pollution, and thermal pollution.
Global warming is another thing. Among the gases emitted when fossil fuels are burned, one of the most significant is carbon dioxide, a gas that traps heat in the earth’s atmosphere. Over the last 150 years, burning fossil fuels has resulted in more than a 25 percent increase in the amount of carbon dioxide in our atmosphere. Fossil fuels are also implicated in increased levels of atmospheric methane and nitrous oxide, although they are not the major source of these gases.