II. Fossil Fuels

A. Coal 1. Coal is organic matter compressed into solid Carbon structures a. Usually from woody plant material 2. Usually forms in areas that were swamps

3. Several types reflection conditions of formation a. Peat is a soft, wet, early coal high in impurities b. Lignite is a soft dry poorly compressed coal c. Sub bituminous and bituminous are impure but very abundant d. Anthracite is the most compressed, purest coal

4. All coal is high in toxic impurities 5. Can be gathered through surface or subsurface mining 6. Produces energy by burning to boil water, stream turns a turbine which cranks a generator to make electricity a. Steam is cooled and cycled back through the system

B. Natural Gas 1. Primarily methane but produced multiple ways a. Biogenic gas comes from anaerobic decay of plants by bacteria near surface b. Thermogenic gas is produced when heat and pressure turn organics into kerogen which breaks down into natural gas 1. contains other gases as well

2. Since it is gaseous, collection can be difficult a. Often exists with other fossils fuels and is lost to atmosphere while mining b. Must be collected using pressurized lines but as natural pressure decreases, must be pumped 3. Starting to collect off of swamps and landfills

C. Oil 1. Plant and animal material treated with heat and pressure for millions of years becomes crude oil a. Crude oil is a mixture of many hydrocarbons

2. Must be extracted by drilling a. Used to be a guessing game but geological resources and seismic data has increased accuracy b. Primary extraction uses natural pressure and pumps to remove crude c. Secondary extraction flushes well with water or steam to remove additional

3. Crude oil must be processed to obtain useful components a. In distillation tubes, hydrocarbons are boiled out, condensed and collected b. About half a barrel of crude oil becomes gasoline and 20% diesel