The main thing that's changed since the 19th Century and the beginning of modern observation has been the widespread increase in fossil fuel use and more greenhouse gases. ~ Kenneth Miller
We all know what fossil fuels are, don't we? We're so used to powering the necessary aspects of our mechanized lives on fossil fuels that we find it hard, almost impossible, to imagine an existence without the likes of kerosene, gasoline, diesel, coal and natural gas! Right from revving up the engines of those fancy cars and bikes to running heavy, industrial manufacturing processes, it's fossil fuels all the way!
However, the most interesting thing about this widespread fossil fuel usage is that we indulge in it even after being well aware of its environmental consequences - none of us is an innocent spectator but is an equal participant in this gang rape of Nature that has been going on for centuries! I know, I always get carried away by sentiments when it comes to issues like this. However, going back to the titular issue, how do fossil fuels work? What is the mechanism behind a black lump powering boiler and blast furnace and how does that golden yellowish liquid make cars and other vehicles move? Well, jump to the next segment to get to the details.
How Fossil Fuels Work - A Brief Overview
Well, the concept behind the working of a fossil fuel, or any alternative, renewable or natural fuel for that matter is very simple. It's all about the conversion of potential energy into other forms of dynamic or direct energy such as heat energy, kinetic energy, electromagnetic energy, etc. Post such conversion, the direct and dynamic energies power the specific applications (furnaces, generators, engines - you name it) which are then mobilized such that the entire mechanic architecture gets activated to perform the function for which it is meant. Now, let's take a look at a couple of common fossil fuel examples and see how they work for a better and clearer understanding of what I just said.
Petrol or gasoline is a petroleum product. Petroleum is a fossil fuel that is the result of dead organic materials, especially of zoological life forms, staying hard pressed for millions of years deep inside the Earth's crust. As centuries went by, the pressure on the Earth kept increasing as the surface of the planet underwent drastic geological changes. Couple all this pressure with the unimaginable heat from the Earth's core, throw in a few million years and dang! There, you have petroleum lying locked in rocks deep beneath the Earth's surface, waiting to be drilled out!
The gasoline that you fill up your car's or bike's tank with goes to the engine. The engine burns this fuel and heat energy is created from the fuel's potential energy. This heat energy gets converted into kinetic energy when gas expansion takes place due to combustion. This kinetic energy is what results in linear piston movement and this movement, in turn, morphs into the rotary motion of the crankshaft.
This crankshaft motion reaches the transmission assembly and passes through it to the differential. From the differential, it passes on as torque to the drive wheels and the vehicle is set in linear motion! This entire assembly of components that generate power and conveys it to those components that come in contact with the road (or any other transportation surface such as air or water) is known as the powertrain.
The biography of coal is more or less the same as that of petroleum. However, there is a slight change of ingredients. Instead of dead animals, it is dead trees this time! All that wood getting buried under the ground in watery graves (yes, most natural coal is layers of antique plant matter that accumulated at the bottom of water bodies several centuries ago) and staying that way for millions of years can hardly turn into anything but coal! Now, as far as coal's action as a fossil fuel is concerned, let's take the example of a thermal power plant that generates electricity by burning coal.
The chemical energy of coal gets converted into thermal or heat energy when the coal is burned. This thermal energy turns into kinetic energy when steam is created. In fact, steam is the form in which the kinetic energy is released. As this kinetic energy reaches the turbines of the power plant generators, it gets converted into mechanical energy as the turbine sets into motion. As the mechanical energy passes through the generator, it gets converted into electromagnetic energy and this energy becomes the final output - electricity.
Speaking of fossil fuels, one cannot miss out on natural gas. A by-product of oil production, natural gas consists mostly of methane with small quantities of ethane and trace amounts of other higher hydrocarbons thrown in. When petroleum is drilled out of the oil wells and undergo pressure reduction process in the reservoir, these natural gases escape as by-products and are captured, processed and transported via various channels to consumer locations.
The most common use of natural gas is for cooking and domestic heating purposes. When natural gas is burned, chemical energy is transformed into thermal energy. This thermal energy manifests in the form of heat and flames upon which food is cooked. Natural gas powered water heaters use the same mechanism whereby the gas in the internal cylinder releases some gas which catches flame and this flame heats that part of the plumbing from where the water current passes, thereby heating it.
So, that's how fossil fuels work. Their combustion leads to a series of energy transformations based upon the final requirement and the equipment used for such energy transformation depends upon the desired purpose. I hope you found the above tutorial on fossil fuels useful and easy to understand. Even in case of renewable natural fuel sources such as solar, water or wind energy, a conversion of one form of energy into another is inevitable if man-made applications are to be run to get the same results as are got on burning fossil fuels. However, by-products of any kind on harnessing these renewable resources are almost non-existent, let alone toxic and ecologically taxing ones.