coal and gas hydrate

Coal and Gas Hydrate Resources


Contents of Entire Course

Coal
Disadvantages of Coal
Mining Coal
Underground mining
Gas Hydrates
Links

adapted to HTML from lecture notes of Prof. Stephen A. Nelson Tulane University


 
 
Coal

The character of coal changes as pressure and temperature increases. We notice a general trend towards higher carbon content as volatiles and moisture are lost. In the crust, at higher temperatures and pressures, metamorphism turns coal into graphite.

Coal itself can be found near the surface and deep below ground. Due to this there are several different ways in which it is mined, depending on the location. Surface, or Strip Mining

Another method employed to mine for coal is to dig underground, removing coal, in the more traditional image of mining. This method creates tunnels and caverns. These can either be dug into the side of a mountain where a known coal deposit outcrops, or into more flat topography, digging straight down. A map view of this style of mine looks like the following: Dark areas are coal that is left behind to hold the overlying rock.
Lighter areas are mined.
The amount of carbon now believed to exist in gas hydrates exceeds that in all known fossil fuels and other organic-carbon reservoirs combined. Methane hydrate, the most common form, is found on the sea floor and in areas of permafrost. This may become a potential source of fuel, but the technology for recovering methane hydrate is still in its infancy.

For those of you who are further interested in the subjects covered in this lecture, the following are links to other web sites covering these subjects.