Energy can be classified under two forms. These are renewable and non-renewable. A non-renewable source of energy is finite in nature – thus, it is considered to be a resource that is incapable of replenishing itself at a rate deemed fit for economic extraction. The following are examples of non-renewable sources of energy:
This solid form of fossil fuel can be classified into three categories: bituminous, anthracite and lignite. Lignite coal can be found close to the earth’s surface. It has possessed a high sulphur content, and can be easily mined. Anthracite is found deep within the earth’s crust. It is dark and shiny in nature and is considered to be the highest quality of coal. Bituminous is the common coal we burn. Aside from the pollutants derived from coal mining and the dangers involved in working in a coal mine, the process of extracting coal itself possess major environmental hazards as unwanted rocks and dirt are excavated from within the earth – which could lead to unstable ground and water pollution.
As the name would imply, this is a fossil fuel that is present in a gaseous state. An example of such gas is LPG and methane. Natural gases are primarily located close to oil deposits and beneath the oceans. Prospecting for natural gas reservoirs bears similarity to oil exploration, and when a gas field is identified, its drilling process is similar to oil drilling. It can also be drilled and stored for future use. It is primarily used for heating our homes and cooking. It is also utilized in the production of medicines, fertilizers and plastics.
Oil is a liquid form of fossil fuel. It is usually yellowish, brownish, or sometimes greenish in appearance. Because of its liquid composition, it is easier to mine, store and transport. Oil forms in reservoirs, and can be challenging to locate. To find it, scientists need to study various landforms and rocks for possible drilling sites. Upon finding the oil, it is then piped to the surface to be refined and stored. In its unrefined state, it is called crude oil. At the refinery, the crude oil is heated up to various temperatures — through to a process known as fractional distillation. It is through this means we get the various forms of fuel derived from crude oil (i.e., Jet fuel, diesel and petrol). Interestingly, oil isn’t only used for transportation, but also in the production of polyester, tyres and plastics.