Fossil fuels: You burn them every day, and yet they are so easy to misunderstand. So, what exactly are fossil fuels?
A long time ago, in a period known as the Carboniferous Era, many plants and animals died. Much of the world was covered in shallow oceans, so the dead matter built up at the bottom of the oceans all over the world. Geological time being what it is, in no time these deposits were covered by layers of rock and buried for a long time. [1] Over millions of years, this dead plant material is compressed and mutated into the fuels we inject into our cars and grill our food over. The type of deposit is determined by what went into it – petroleum tends to be made from dead animals of different varieties, while coal is usually made from plants. [2] An interesting thing to note is that fossil fuels technically are renewable resources. Assuming a constant rate of plant death, you should see a fairly consistent rate of fossil fuel development millennium over millennium. Unfortunately, we have a voracious demand for dead plant matter, so we are burning through our fossil record in record time. So to us, fossil fuels appear to be, and may be considered, nonrenewable. [3] Fossil fuels contain high levels of carbon. This is why they are bad for our environment, but also the key to how they generate heat. For example, when coal is burned, energy is added to the equation and a reaction occurs when carbon and oxygen are combined. This reaction produces water, CO2, and energy that we see as light and feel as heat. [4] But this burning would be pointless if the energy is not captured. If you are generating power, the most common method of doing the energy conversion is to use the heat to boil water. The water turns into steam, which is then used to turn a turbine hooked to a generator, in a process quite similar to how a wind turbine works. While this chemical to mechanical to electrical conversion may seem inefficient, it is better than any other technique for power generation we have as far as return on investment goes, except for maybe hydroelectric. [5] Oil often produces power in a slightly different way. The basic method by which a car engine works is to inject fuel into a cylinder with a rod and blow up the fuel. The explosion shoves the rod down, which is conveniently attached to a camshaft. At the bottom of the stroke, a valve is exposed that lets out the dirty air full of burnt gas, and fresh air is pumped in. Then, more gas is released, ignited, and exhausted. Amazingly, this happens many, many times per minute. Take a look at your RPM dial sometime to get an idea for just how many. [6] Despite the fact that they are getting more difficult to find, fossil fuels are still going to be around for a very long time. There is a lot of energy stored in fossil fuels, and they still beat most of our replacement technologies. Batteries are immensely inefficient, solar doesn’t produce enough power to move a commercial car, and hydrogen not only has to be produced (usually from fossil fuels), it has to be stored – something that has proven to be quite difficult. All of these factors make it apparent that we will be hearing the familiar hum of the internal combustion engine for many more years. Sources: 1. http://www.energyquest.ca.gov/story/chapter08.htmlWhy Fossil Fuels Produce Power
Why Fossil Fuels Won’t Go Away Anytime Soon
2. http://en.wikipedia.org/wiki/fossil_fuel
3. http://www.discoveringfossils.co.uk/fossilfuels.htm
4. http://en.wikipedia.org/wiki/combustion
5. http://www.youtube.com/watch?v=e_ccrgklyzc
6. http://auto.howstuffworks.com/engine1.htm
