The Fossil Fuels – Coal, Oil & Gas

Despite climate change and green issues, polluting fossil fuels still supply more than 80% of the world’s energy needs. The trigger for the industrial revolution, without these fuels mankind would have struggled ever to reach the world we have today. Almost everything you see, use, wear or eat is linked in some way to fossil fuels whether its for the energy to transport it, made out of it (in the case of plastics), or used in a production process.

Oil & Gas

All fossil fuels are created by dead organisms. Oil is formed from organisms – mostly plankton – that died millions of years ago and settled on the ocean floor. This massive grave is slowly compressed by the weight of sediment and rock above eventually producing the thick black liquid we know as crude oil – arguably the most important resource on the Earth. Natural Gas is formed in this process and accumulates in resivoirs usually above oil.

The first oil well opened in Pennsylvania in 1859 and was drilled to a great depth of 21meters. Today – as oil reservoirs dry up – oil companies can drill as much as 5000 meters to reach oil. Todays drills can drill in almost any direction as they are steerable allowing one well to drain a vast area of oil.

Oil Rigs are the some of the world largest constructions and marvels of construction, costing billions to build. Likewise, the world biggest ships are oil tankers of incomprehensible size. Natural Gas is extracted in much a similar way to oil as it is often found in the same locations. The oil industry is responsible for massive amounts of damage to the environment, including oil spills which devastate coastlines, killing fish and birds. Annual extraction of oil is almost 25 billion barrels a year.

Coal

Coal – the third and most abundant fossil fuel is formed in a similar manor except that it is the remains of tropical forests, compressed to form coal. It is harder to extract as it is a solid and is also more polluting than oil or gas. Surface open cast mining is the main method for mining coal however deep shaft mining is also used.

The fuel powered the industrial revolution and it is still used in massive quantities today although has been some what surpassed by oil in importance. Surface mining, although a lot cheaper and safer, has great impact upon the local area. Some open cast mines use some of the largest machines in the world to extract the coal – although in some mines only 10% of extracted material is coal, leading to vast spoil heaps.

Uses of Fossil Fuels

Coal and gas are almost solely used for energy production. Usually the process involves burning the fuel to heat water and generate steam, this steam - under high pressure - is used to turn huge turbines which are connected to generators. The rotation in the generator triggers electricity to be produced. This is then stepped up in a transformer for transfer through overhead power lines into a national grid.

Oil, however, is also used extensively for other things. Through fractional distillation - the process of separating crude oil into its different 'fractions' by heating it - various substances are acquired: Petroleum, Diesel Oil and kerosene as well as heavier bitchumen. Oil is also used in the production of plastics - found everywhere today. Coal is also used in the production of steel.

The Future

Coal reserves are estimated to be around a 1,000 billion tones, enough to last a few more centuries. However, it is extremely polluting and this is likely to limit its use. Gas supplies should last another century and being the cleanest burning fossil fuel will likely be used to the end. Oil, on the other hand, is likely to be exhausted within 50 years even with exploration finding new reserves and efficiency of extraction and use increasing.