Lesson 4.02 Fossil Fuels: Types, Uses, and Formation

 

Fossil fuels are nonrenewable sources of energy. Nonrenewable energy sources cannot be replaced by natural means to replenish them as fast as they are being used up. Nonrenewable sources cannot be sustained for unlimited human use. Fossil fuels, nuclear energy, or any mineral located in the Earth are sources of nonrenewable energy. Nonrenewable energy sources come from processes that take millions of years to complete. So once they are used up, they are gone and cannot be replaced or used anymore.

Renewable resources have the ability to be replaced or renewed and remain available for use. They are sustainable for unlimited human use. Examples of renewable sources of energy are things like:

• solar energy - energy from the sun in the form of light
• hydropower - energy stored in water due to its position
• wind energy
• biomass energy - energy trapped in living or once living organisms: wood, grass, corn, etc.
• geothermal energy - energy trapped deep in the Earth's crust

There are three major types of fossil fuels:

• petroleum (oil),
• coal, and
• natural gas.

The fossil fuels on Earth were formed well before the presence of dinosaurs, which is why they are called fossil fuels. Fossil fuels were formed in the Earth's crust out of dead organisms that lived hundreds of millions of years ago. Prehistoric plants and animals died, sank to the bottoms of swamps and oceans, and were covered by layers and layers of sediments and rocks. They layers increased the temperature and pressure on the plant remains, turning them into fossil fuels.

 

Oil, also known as petroleum, formed over 300 million years ago. It is thought that tiny ocean organisms known as diatoms are responsible for creating oil. Diatoms are small organisms that are photosyntheticorganisms that are able to make food directly from carbon dioxide and water using energy from the sun. These diatoms died and sank to the bottom of ocean where they were covered by layers and layers of deposited sediment. Under the great pressure and temperature created by the layer of sediments, they were turned into oil/petroleum and natural gas. Oil is pumped out of the ground through shafts that have been drilled into the ground or ocean floor until the petroleum is reached.

Petroleum is used to make products like gasoline, diesel fuel, kerosene, tar/asphalt, plastics and rubber type products. Oil products are used in cosmetics and medicines. Most of the petroleum in the U.S. is used for energy in transportation.

It is estimated that about 2/3 of the oil that the U.S. uses is imported from several different foreign countries. It is estimated that the world uses more than 85 million barrels of oil per day with the U.S. using about 19 million barrels of that.

Open the Oil formation interactive to watch an animation on coal and natural gas formation.

 

Coal is a hard, rock-like material that is made up of carbon, hydrogen, oxygen, nitrogen, and sulfur. There are three main types of coal:

• anthracite,
• bituminous, and
• lignite.

Coal is classified into the three types based on hardness. Anthracite is the hardest and lignite is the softest. The hardness is related to the amount of carbon. Anthracite has the most carbon and lignite has the least carbon. More energy is contained in the Anthracite with the least amount of energy being found in lignite.

Coal was formed hundreds of millions of years ago when prehistoric plant life died and sank to the bottom of swamps and was covered by layers and layers of sediment and rock. The increased pressure and heat of the remains, turned into coal.

Coal is located in most of the lower 48 states. It is mined using a couple of different methods.

• One method is by digging a horizontal or vertical shaft in the ground through which miners descend to dig out the coal.
• Another method is called strip mining. In this process, the layers above the ground are stripped off by huge steam shovels until the coal is reached.

The main use of coal is to supply energy to generate electricity in thermoelectric power plants. Coal is burned and used to heat water into steam. The steam turns turbines that turn a coil wire around a magnet. This creates a flow of electrons which is known as electricity. In 2008, almost 49% of the electricity in the United States came from coal. There is an abundant supply of coal in the U.S. and it is relatively inexpensive.

 

Natural gas is composed mostly of the organic compound methane (CH₄). Natural gas is often found near oil/petroleum deposits. Natural gas is trapped in layers of sedimentary deposit known as shale.

Natural gas forms much like the other fossil fuels: prehistoric plants and animals died and became covered by layers and layers of sediments producing the natural gas.

Natural gas is an odorless gas that is used in heating and cooking. It is estimated that almost half of the homes in the United States are heated by natural gas. Natural gas is treated with mercaptan. Mercaptan is a substance that smells like rotten eggs to allow leaks to be detected. Because of its simple chemical makeup, it is the cleanest burning fossil fuel.

Most of the natural gas reserves are located in the Middle East and Europe. The United States has a reserve that is estimated to last for the next 60 plus years. The top natural gas producing states in the U.S. are Texas, Oklahoma, New Mexico, Wyoming, and Louisiana.

Watch How Were Fossil Fuels Formed? (2:52) to see how natural gas is formed.

 

Think back to Unit 2 when you learned about developed and developing countries. Developed countries have a higher standard of living than developing countries. Developed countries require more energy than developing countries. Technological advancements in developed countries require more energy use and ultimately create the higher standard of living. Therefore, developed countries depend more on energy sources such as oil to keep them advancing.

Many of the developed countries do not have natural resources such as fossil fuels to meet their needs. They depend on getting these resources from other countries - often developing countries. This can cause friction between these countries when political, social, and religious differences exist.

Because fossil fuels are such a needed commodity for developing countries, conflicts can occur between the nations that have the resources and the nations that need the resources. Nations that have affordable, abundant sources of energy that can be used and accessed more readily by all citizens are more technologically advanced and the citizens have higher standards of living. Many developing countries have an abundant of natural energy resources, but it is not made affordable or available to all citizens. The resources are controlled by a select few in the country which creates a large economic gap between the rich and poor. Having access to affordable energy is important in increasing the standard of living within countries.