Sustainable Air Quality

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Sustainable Air Quality

• Michael Roberts
• February 4, 2002

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Background

• Fossil fuels are consumed largely by industry.
• Sulfur and Nitrogen compounds are major fossil
  fuel pollutants.
• Elements such as carbon, sulfur, and nitrogen are
  redistributed by the industrial metabolism.
  These elements can be harmful if doses are high
  and for lengthy periods.
• In order to understand the benefits and/or
  effects of fossil fuels, a material flow diagram
  should be produced for the ecosystem analogue for
  humans.
• The process of this diagram starts with the
  mining process, then goes to the consumers and
  finally reaches the recyclers.
• Combustion of oil and coal products and the
  smelting of metals, are responsible for the
  majority of anthropogenic sulfur and nitrogen
  emissions.
• Since the 1880s, fuel consumption has steadily
  increased.

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Background

• Since 1850s, the fuel source has changed
  throughout the years.
• Throughout history, fuel consumption has
  increased, but depending on the time period, a
  certain energy source may increase dramatically
  or decline dramatically.

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Sulfur Production Emissions

• After combustion, sulfur is transformed into SO2
  SO3.
• The environmental impact of sulfur begins at the
  mining process and continues to the atmosphere as
  sulfurous haze.
• There are three (3) main coal mining regions the
  appalachians, the midwest (interior), and the
  west. Each region has a different amount of
  sulfur imbedded into the mined coal.
• For sulfur contaminants, we can figure out the
  sulfur contaminate by the equation MiCiPi where
  Pi is production rate and Ci is mass contaminate.
• Western coal has a significantly lower sulfur
  content than Midwest coal.
• Coal has been in use since about 1920. Even
  though coal production has increased
  significantly, the sulfur emission has only risen
  by 12.
• Before 1945, coal was distributed among electric
  utilities, residential, railroad, and commercial.
  Today, coal is used mainly by electric utilities.

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Sulfur Production Emissions

• Sulfur mobilization from combustion oil products
  can be determined from production or consumption
  data.
• Sulfur mobilization increased untill about 1960
  and then levels off at about 3-4 million tons per
  year.
• Methods have been used to reduce sulfur
  mobilization in crude oil.
• The by-product of recovering sulfur from crude
  oil is sulfuric acid. About 4 million tons of
  sulfuric acid is recovered yearly from crude oil.
• About 50-70 of sulfur oxides are removed from
  copper smelting.
• Since the turn of the century, sulfur emissions
  from metal smelting fluctuate between 0.5 1.5
  million tons per year.

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Nitrogen Oxides Emissions

• Nitrogen can be found in both the natural
  atmosphere and the biosphere.
• Transportation is responsible for almost half of
  all nitrous oxide emissions.
• The combustion temperature determines the NOx
  production.
• Nitrogen oxide is formed by fixation of
  atmosphere nitrogen at high temperatures of
  combustion rather than by oxidation of nitrogen
  in fuel.
• NOx emissions are calculated through the amount
  of fuel consumed and multiplying by an emission
  factor.
• Since 1970, NOx emission output has stayed
  relatively constant.

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Summary

• National sulfur contaminates have fluctuated
  between 8 and 16 million tons per year.
• Since 1970, coal is responsible for the majority
  of sulfur oxides and nitrous oxides are a result
  of internal combustion engines.
• Today, coal is used primarily for boilers in the
  electric utility facilities.
• To control sulfur oxides, sulfur will have to be
  removed from the fuel and flue gases.
• To control nitrous oxide, technology will have to
  improve the combustion process.

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What I learned

• Technology will have to reduce NOx. There isnt
  much we can do.
• The Midwest mined coal is the highest sulfur
  content among the U.S.
• Even though coal production has increased, the
  sulfur pollutant hasnt increased by the same
  amount that the production has increased by.
• The by-product of oil products is sulfuric acid.