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US Coal resources

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Title: US Coal resources


1
US Coal resources
2
World distribution of coal
3
World coal production
4
Problems with coal
  • Like oil and natural gas it will not last forever
  • Best estimates are 100-200 years
  • Be skeptical of large estimates, based on new
    discoveries, new technologies
  • It is not a clean fuel source, lots of
    environmental impact from using coal
  • Environmental effects of surface (strip) mining
  • CO2 (carbon dioxide) emissions impact environment
    (green house effect)
  • SO2 (sulfur dioxide) emissions pose health risks
  • Mining risks (mine accidents, black lung disease)
  • Is it really cheap?
  • From an NRC on the hidden costs of energy
    production
  • In 2005 the total annual external damages from
    sulfur dioxide, nitrogen oxides, and particulate
    matter created by burning coal at 406 coal-fired
    power plants, which produce 95 percent of the
    nation's coal-generated electricity, were about
    62 billion
  • This is twice as high as the cost of the coal
    itself

5
Coal Liquefaction
  • Process of producing synthetic fuel from coal
  • Direct and indirect process to achieve this
  • Direct
  • Carbonization- produces coal tar, oil, water
    vapor, synthetic gas and char (a solid residue).
    Produces fluids that are of low quality for fuel.
  • Hydrogenation add H2 to coal mixed with solvents
    and catalysts. No proven commercial value to the
    process
  • Indirect Fischer-Tropsch process (coal
    gasification)
  • Coal is gasified into syngas, which is converted
    to gasoline ad diesel.

6
Coal gasification
  • Process of producing coal gas, which can be
    converted into gasoline and diesel fuel and
    Hydrogen.
  • Coal is heated and blown with oxygen and steam.
    Produces syngas, which can then be turned into
    gasoline as described on the previous slide.
  • Or syngas is fed into another reaction which
    produces H
  • Produces by-products which are environmentally
    damaging and need mitigation techniques
  • Produces more CO2 than crude oil refinement-needs
    carbon sequestering technologies.

7
Non-conventional fossil fuels
  • Tar sands, shale gas and shale oil
  • Until recently, these were not considered as a
    viable large scale contributors to our energy
    needs
  • Technological advances and rising energy prices
    have brought shale oil and gas to the forefront
    as possible short term solutions

8
Tar Sands
  • Deposits of sand mixed with a thick hydrocarbon
    substance called bitumen
  • Bitumen is so thick (viscous) that it does not
    flow. So sands must be transported to a
    processing plant.

9
Locations
  • Primarily in Canada
  • Tar sands form where petroleum migrates upward
    into deposits of sand or consolidated sandstone.
    When the petroleum is exposed to water and
    bacteria present in the sandstone, the
    hydrocarbons often degrade over time into
    heavier, asphaltlike bitumen.
  • 170 billion barrels considered economically
    recoverable.

10
Tar sands processing
  • Tar sand is placed in rotating
    drums along with water and
    caustic soda that separates the
    water, soda and bitumen.
  • Bitumen is placed in a centrifuge and cracked
    into naptha, kerosene and heavy fuel oil
  • Requires a lot of water (about 3 barrels of water
    for one barrel of oil produced
  • Waste is stored on site in waste water ponds
  • Similar energy density to shale oil, much less
    than coal

11
In situ processing
  • Two parallel horizontal oil wells are drilled in
    the formation. The upper well injects steam and
    the lower one collects the water that results
    from the condensation of the injected steam and
    the crude oil or bitumen.
  • The injected steam heats the bitumen and lowers
    its viscosity, which allows it to flow down into
    the lower wellbore.
  • The water and bitumen is recovered to the
    surface by several methods including a natural
    steam lift or by pumps that work well for moving
    high-viscosity fluids with suspended solids.

12
Keystone XL Pipeline
  • Proposed pipeline to deliver tar sands oil and
    bitumen (for further processing) to multiple
    locations in the US.
  • Cost 7 billion

13
Concerns about Keystone XL
  • Portions cross known seismic regions
  • Crosses native American reservations
  • Concerns over damage to sacred sites
  • Contamination from leaks or from tars sands
    production itself
  • Leak or spill from any section would have
    environmental impacts
  • Overall tar sands usage produces more greenhouse
    gasses than conventional oil
  • Does not really address energy independence
  • How much will be kept in the US vs being
    exported?
  • If immediately approved, wont effect prices at
    the pump until 2014 and there is no consensus on
    its impact on gas prices, though it will be
    smaller than 10cents/gallon.
  • Compare to TransAlaska pipeline
  • 7 incidents in 35 years, 2 from sabotage(people
    putting holes in the pipeline), 1 from human
    error, 1 from earthquake(no leak), 3 from
    equipment failures

14
Shale oil vs oil shale
  • Shale Oil
  • The oil produced from oil shale
  • Oil Shale
  • Also called kerogen shale
  • Rocks that contain kerogen
  • Kerogen a solid mixture of organic compounds from
    which shale oil can be produced
  • Shale oil is a substitute for crude oil

15
Oil Shale
  • Oil Shale largest deposit is found in the Green
    River Formation
  • 50 million years ago, this area was covered by 2
    large tropical lakes. Organic material at the
    bottom of the lakes combined with sediment and
    formed a carbon containing mudstone, called
    marlstone.

16
Green River Formation
17
Recovery methods
  • Getting the oil is not easy, nor is it cheap, but
    it is becoming economically feasible. Same amount
    of coal produces much more energy.
  • Traditional removal process require heating (a
    process called retorting) of the shale to remove
    the hydrocarbons which expands the remaining
    shale by 35. Need a deposit site to handle the
    waste
  • This process also requires lots of water, Green
    River formation is in a very dry part of the
    country.
  • In situ (on site) recovery methods are being
    developed to overcome these difficulties

18
Recovery methods
19
Recovery methods
20
Recovery methods
21
How much?
  • 0.5-1.1 trillion barrels of technically
    recoverable oil shale oil in the US. (note that
    the word technically recoverable includes proved
    and unproved reserves)
  • Based on current demand, this would provide the
    US with enough oil for 400 years.

22
Shale Gas
  • Gas deposits trapped in shale formations

23
Fracking
  • Hydraulic Fracturing
  • A process which uses a high pressure liquid to
    create fractures or veins on rock to allow
    petroleum, natural gas or other substances to
    flow
  • Used as far back as 1860s to extract oil in
    Pennsylvania, new York, West Virginia and
    Kentucky

24
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25
Issues
  • Water useage Fracking takes a large volume of
    water. The average well uses 3-8 million
    gallons/week.
  • Many of the chemical additives used are toxic and
    known carcinogens-possibility exists of
    contaminating ground water supplies
  • Flowback the fracking fluids are further
    contaminated as they flow back through the wells
    by naturally occurring minerals and possibly
    naturally occurring radioactive substances
  • Methane release-can cause explosions, can
    contaminate ground water and is a greenhouse gas
  • Earthquakes-the additional fluid can cause fault
    lines to slip more easily

26
Flaming Faucets?
  • http//www.youtube.com/watch?vUrnnQ17SH_A

27
How much?
  • In the US, probably enough for about 100 years,
    at current rate of consumption
  • If we increase consumption, this number will go
    down.
  • Recovering methane from coal beds can offset the
    consumption increases a little
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