1. Uses
Power plants: gas turbines have a higher efficiency in converting the fuel to power than steam turbines (we will talk about these turbines later) . Plants are cheaper to build and more environmentally friendly.
Transportation: Use is growing, but limited by range (need to store the fuel in the vehicle under high pressure and there is not a widespread distribution system).

2. Not the solution! Will not solve our energy problems
Most comes from domestic production, as shipping is difficult.
US has consumed 85% of its available natural gas and at the current rate of consumption, we have enough for about 30 years.
Methane from coal beds can be used to produce natural gas, which will increase supply somewhat.

3. Coal Formation

4. 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.

5. Coal vs Diamonds
Diamonds need high temperature and pressure, which is found at large depths in the Earth, usually between km deep.
Coal mines reach depths of 2000 ft (0.6 km)
Don’t form from coal, dating of diamonds shows them to be older than the oldest known plants that existed on the planet and it is unlikely to find coal that deep.
Confusion stems from both being high in carbon content

6. US Coal resources

7. World distribution of coal

8. World coal production

9. 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
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

10. 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.
Produces more CO2 than the crude oil refinement-needs carbon sequestering technologies.

11. 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

12. 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.

13. Green River Formation

14. 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

15. Recovery methods

16. Recovery methods

17. Recovery methods

18. 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.

19. 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.

20. 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

21. 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.

22. 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.