Fossil fuels are natural resources that are created by the long-term decay of dead organisms and are burned to produce energy. This type of fuel typically is characterized by high carbon and hydrocarbon content. Coal, oil, and natural gas represent the majority of fossil fuels used globally. Burning fossil fuels releases a bi-product of carbon dioxide into the air, known as greenhouse gases, which are suspected of causing rising surface temperatures on the Earth. Fossil fuels are a diminishing commodity in high demand; for example, more than 85% of the energy used by the United States comes from burning fossil fuels. Alternative fossil fuels are also carbon-based forms of fuel, but are obtained from different resources, such as oil sands and converting coal into liquid. Alternative fuels have the same ability to produce energy through burning, but may be more readily available.
The most common alternative fossil fuels may be oil sands, also known as heavy oil, and coal-to-liquids. Heavy oil or oil sands is a mixture of sand, clay, and oil. It undergoes a heating process, raising the internal temperature high enough to separate the mixture’s different components. The refinery then extracts the oil, commonly known in the industry as light crude. Coal-to-liquids is a liquefying process that transforms coal into a product similar in use to light crude oil. South Africa is home to one of the largest coal-to-liquid refining industry in the world and can fuel up to 30% of its gasoline needs using this alternative fossil fuel. Coal-to-liquids have the added benefit of not producing as much carbon dioxide as traditional oil.
One of the benefits of alternative fossil fuels may be lowered fuel costs. A disadvantage of fossil fuel is that the resources are limited and require many thousands of years to regenerate. Global energy costs continue to rise while the existing supply of fossil fuels steadily declines. Alternative fossil fuels may offer new sources for similar types of energy, and are available in many countries that might not have internal sources for light crude oil or coal. Additionally, countries with high deposits of coal could transform their natural resources into a coal-to-liquid alternative fossil fuel, which may lower import and usage costs on energy. Similarly, countries that lack access to light crude oil but have large fields of heavy oil could invest in refining technology and transform that heavy oil into usable light crude.
The impact these fuels have on the environment and the high up-front investment costs required may represent the largest disadvantages to switching from conventional to alternative fossil fuels. Heavy oil and coal-to-liquid release between 20% and 50% more carbon dioxide into the air during production than conventional oil and coal do during actual use. Extracting and refining heavy oil also may pose a contamination threat to local water supplies and may also have the potential for massive disturbance of existing habitats. It also typically requires a major financial investment to establish the equipment to extract and refines heavy oil from natural fields to make it usable by oil- and gasoline-powered machinery. Unlike light crude oil, heavy oil does not rise from the ground in a form immediately usable by manufacturers.