1. Coal Formation

2. Coal types
Peat: Youngest form of coal, lowest grade, low quality fuel and organic material for gardeners
Lignite: 150 million yrs old, 50% carbon content
Bituminous: 300 million years old, 50-80% carbon
Anthracite: 500 million years old, 95% carbon, hardest and cleanest burning coal.

3. US Coal resources

4. World distribution of coal

5. World coal production

6. Problems with coal Like oil and natural gas it will not last forever
Best estimates are 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

7. 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 commericial value to the process
Indirect:Fischer-Tropsch process
Coal is gasified into syngas, which is converted to gasoline ad diesel.
Produces more CO2 than the crude oil refinement-needs carbon sequestering technologies.

8. 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 pervious slide.
Or syngas is fed into another reaction which produces H
Produces by-products which are environmentally damaging and need mitigation techniques

9. Shale oil and tar sands: Nonconventional fossil fuels
Shale oil: 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.

10. Green River Formation

11. Recovery methods
Getting the oil is not easy, nor is it cheap, thus as long as there is abundant, cheaper coal, this resources will remain untapped
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

12. Recovery methods

13. Recovery methods

14. Recovery methods

15. 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.

16. 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.

17. 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
Similar energy density to shale oil, much less than coal

18. 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.

19. Fossil fuels-going the way of the dinosaur?
Total resource vs proved reserve
Total resource is the amount of a resource that is known to exist
Proven resource is the amount that is recoverable under current economic and technical conditions
They are not equal!
Barriers to untapped resources
Restrictions on offshore oil drilling
Strip mining of coal-environmentally a bad idea
Tar sands mining has been referred to as the “most destructive project on Earth”
No mater how you look at it, fossil fuels follow a Hubbert type curve, they will run out! It is a question of when, not if.

20. Heat Engines
How do we get the heat energy of the fuel and turn it into mechanical energy?
Simply put we combine the carbon and hydrogen in the fuel with oxygen.
2 reactions that occur are
C + O2  CO2 + heat energy
H2 + O  H2O + heat energy
This process is just the reverse of photosynthesis.

21. Just a little chemistry
For example, the the equation for burning heptane looks like:
C7H O2  7CO2 + 8 H2O X 106 calories per 100g of Heptane
1.15 x106 is called the heat of combustion for heptane. Every hydrocarbon has such a number
It is the maximum amount of energy for a certain amount of mass of a substance you can extract.
It represents the energy from the sun stored in the fuel since ancient times