Waste To Electricity Generation
Most of the electricity we use is generated by burning fossil fuels to produce steam that drives steam turbines, which then drive electric generators.
Today, most of the electricity we use is generated by burning fossil fuels to produce steam that drives steam turbines, which then drive electric generators. While in large quantities, the global supply of fossil fuels is finite. Rapid depletion of these resources will have significant consequences for energy sources, as well as plastics manufacturing.
New sources of fossil fuels continue to be discovered, although the rate of discovery is slowing while the difficulty of extraction increases simultaneously. More serious concerns are raised about the emissions that result from burning fossil fuels.
Fossil fuels are important deposits of deep buried carbon. When the fossil fuels are processed, the carbon is converted into carbon dioxide, which is then released into the atmosphere. The estimated CO2 emission from the global electricity industry is 10 billion tons per year, resulting in an increase in atmospheric carbon dioxide levels, worsening the greenhouse effect and contributing to global warming.
According to Environment Canada:
"The electricity sector is unique among industrial sectors in its very large contribution to emissions associated with nearly all air issues. Electricity generation produces a large share of Canadian nitrogen oxides and sulfur dioxide emissions, which contribute to smog and acid rain and the formation of fine particulate matter. It is the largest uncontrolled industrial source of mercury emissions in Canada. Fossil fuel-fired electric power plants also emit carbon dioxide, which may contribute to climate change. In addition, the sector has significant impacts on water and habitat and species. In particular, hydro dams and transmission lines have significant effects on water and biodiversity."
Coal mining practices in the United States have also included strip mining and removing mountain tops. Mill tailings are left out bare and have been leached into local rivers and resulted in most or all of the rivers in coal-producing areas to run red year round with sulfuric acid that kills all life in the rivers.
Depending on the particular fossil fuels and combustion methods, other emissions can also b released. Emissions like sulfur and nitrogen oxides contribute to smog and acid rain. In the past, plant owners addressed this problem by building very tall flue gas stacks, so that pollutants would be diluted in the atmosphere. While this helps reduce local pollution, it does not help at all with global problems.
Fossil fuels, especially coal, also contain dilute radioactive material that when released into the environment, may carry 100 times more radiation than a nuclear power plant. Fly ash, a by-product of coal, may also contain high concentrations of uranium that can leach into water and soil and affect cropland.
Coal also contains traces of heavy elements such as mercury and arsenic. Mercury vaporized in a power plant boiler can remain suspended in the atmosphere and circulate around the world Mercury is toxic and can cause damage to nervous, immune, and digestive systems, as well as vital organs like kidneys, heart and lungs.
Mercury emissions from power plants in the United States are believed to be about 50 tons per year in 2003, and several hundred tons per year in China.