Coal
What is needed to form coal deposit?
- Need climate supportive of abundant plant growth - Moderate temperature - Subsiding environment (sedimentary basin) - Large river deltas are best locations
what coal deposits look like
- form thin seam (1-10 meters) - have to move a lot of waste rock (engineering difficulties)
Rough estimate of coal ratio
-20 (waste rock) : 1 (coal) -Considered economic
Why is it called King coal?
-Ample supplies of it -Requires minimal processes -Fuels industrialization all around the world -China is largest user (4 times as much as US)
How is coal formed?
-Coalification -Land plants dies but doesn't rot, and is buried -Burial increases temp and pressure
What happens as coal rank increases?
-Increase in carbon -Identifiable plant remains disappear -Energy content increases
Coal rank
1. Peat (lowest energy per mass) 2. Lignite (first type of true coal) 3. Bituminous (most common) 4. Anthracite (highest energy per mass)
Global coal burn rate
8 gigatons/ year
Where does coal come from?
Land plants