Coal

1. Coal By Mackenzie Howie Grace Hickey And TheaBruggemann

2. How is coal formed? • As plants and trees died, their remains sank to the bottom of the swampy areas, accumulating layer upon layer and eventually forming a soggy, dense material called peat. • When the dead vegetation accumulated in the swamps and got covered with sand and mud would take place as a cycle.

3. How is Coal Formed Cont. • More layers of soil and vegetable matter accumulated over the peat, oxygen, hydrogen and water were pressed out of it. By increase in pressure and further compacting between layers of sediments, the peat went through many changes eventually turning into coal. • This process takes hundreds of millions of years to form

6. Different Types: Peat • a heavy dark brown material consisting of about 50%-60% carbon. Peat deposits are still forming today. The decaying plant remains form it.

8. Different Types: Lignite • over time peat deposits become buried beneath thick layers of sediments. The sediments cut off the materials from airborne bacteria, which prevents any further decay. The weight of the sediments presses down on the peat, compacting it in squeezing out water and gases. This process forms a new material called lignite, or brown coal. Lignite is a sedimentary rock. Lignite consists of about 70%-85% carbon.

10. Different Types: Bituminous • as more sediment is deposited, the lignite is further compressed. The rock becomes more dense forming bituminous coal, or soft coal. This is the most common type of coal. Bituminous coal is a sedimentary rock containing about 85%-90% carbon. When bituminous coal is burned, it forms a smoky flame.

12. Different Types: Anthracite • If bituminous coal is exposed to further heat and pressure within the earth, it can change into metamorphic rock called anthracite, or hard coal. Anthracite is about 90%-98% carbon. Anthracite contains more carbon than bituminous coal does, but it is more difficult to ignite. However, once it is ignited, anthracite burns with no smoke.

14. How is Electricity Produced From Coal? • First the coal is mined and taken to a power plant. • Then the coal is burned in a boiler that causes the water in the boiler pipes to become steam. • The steam travels through the pipes to the turbine. • The steam spins the turbine blades.

15. How electricity is produced from coal cont. • The spinning blades turn a shaft connected to the generator. • In the generator, big magnets spin close to coils of wire. • When this happens, electrical current is produced in the wires. • Then the electricity goes out through wires to homes, schools, and business

17. Supplies of Coal • known sources of fossil fuels that have not yet been removed from the ground are called reserves. The fossil fuel with the most abundant reserves is coal. Even so if the use of coal continues at its present rate, all the worlds reserves of coal will be used up within 200 years. Scientists estimate that the words as yet unknown coal deposits could possibly last another 900 years. The United States has about 20% of the worlds coal. The supply available from reserves and unknown sources within the United States will last about 400 more years.

19. Environmental concerns • Increasing our use of coal would increase concern over several environmental issues. Two main concerns associated with the use of coal are: • pollution caused by emissions of contaminants such as sulfer dioxide, nitrogen oxides, and mercury, which effects human and environmental health. • Greenhouse gases, emissions of which contribute to global warming

20. Environmental Concerns cont. • The main legislation that applies to air pollution is the Clean Air Act (CAA). Under the CAA the U.S. Environmental Protection Agency set limits on the amount of certain pollutants that can be released into the air. By using the technology that either traps the pollutants before they are released into the air or that changes them into less harmful pollutants, the amount of air pollution can be controlled. Burning greater amounts of coal however, would mean that more pollutants would need to be controlled through these methods.

21. Environmental Concerns cont. • Burning greater amounts of coal would also release greater amounts of greenhouse gases, especially carbon dioxide which is the main gas associated with global warming. Little legislation exists in the U.S. right now that applies to global warming. Therefore, increasing our coal use could contribute greatly to global warming and cause major environmental problems.

25. Advantages of Coal • coal is the most abundant resource • coal is inexpensive when compared to other fossil fuels(or alternative energy sources • coal is versatile enough to be used for recreational activities • burning coal can produce useful by-products that can be used for other industries or products

26. Advantages of Coal cont. • electricity produced from coal is reliable • coal can be safely stored and can be drawn upon to create energy in a time of emergency • coal based power is not dependent on weather which cannot be said for alternative forms of renewable energy such as wind or solar power • transporting coal does not require the upkeep of high pressure pipelines and there is no requirement for extra security when transporting coal • using coal reduces the dependence on using oil, which is often found in nations where there is unstable political regimes

28. Disadvantages of Coal • Burning coal emits harmful waste such as carbon dioxide, sulfur dioxide, nitrogen oxides, sulfuric acids, arsenic and ash. It also emits twice as much carbon dioxide when compared to natural gas to produce the same level of heat, which increased the levels of harmful greenhouse gases emmited into the earth atmosphere. Carbon dioxide emmisions from the burning of fossil fuels now account for 65% of the extra carbon dioxide in the atmosphere.

29. Disadvantages of Coal cont. • The burning of coal by large scale factories to power industry has led to acid rain in some regions. • Coal can be cleaned an/or turned into a liquid of gas but this technology had yet to be fully developed and adds to the expense of making fuel via coal. • Coal mining can scar the landscape and the equipment used for mining is large and very noisy which may affect the local wildlife.

30. Disadvantages of Coal cont. • Transporting coal can be problematic because it requires an extensive transportation system and can also cause additional pollution in the form of emissions from transportation vehicles such as lorries • There are limited stocks of coal remaining – they will be entirely depleted in this millennium if we continue burning coal at this rate (nonrenewable) • The mining industry can create health difficulties for miners and fatalities from the dangerous industry • Burning dirty coal can create significant pollution problems

33. The End