Fuel

A fuel is a substance that is changed in some way to produce heat, electricity, or other forms of energy. This is usually by being burnt in fire, although there are exceptions, such as nuclear fuel. Fuel can be divided into two main types: fossil fuels and other fuels.

 Fossil fuel 

There are several kinds of fossil fuels:
 coal
 oil and products that are refined from oil (gasoline, diesel, kerosene)
 natural gas
Some people do not want us to use fossil fuels because they may pollute the environment. Because all fossil fuels are made out of carbon, burning them makes carbon monoxide and carbon dioxide. Too much carbon dioxide in the air causes a greenhouse effect. Carbon monoxide in the air is poisonous to humans and animals. Fossil fuels are also non-renewable, or renew extremely slowly (thousands to hundreds of millions of years). This means that we will eventually run out of fossil fuels.

 Other fuels 
Other fuels are not made from fossils. Some of these, like nuclear and hydrogen, do not have carbon in them. Others, like wood or ethanol, do have carbon in them. Some examples of these fuels are:
 Nuclear fuel (uranium, plutonium, thorium, etc.)
 Hydrogen
 Biofuels from biomass
 Firewood
 Biodiesel (a diesel-type fuel made from plants)
 Ethanol (made from grains or other plants)
These fuels are renewable. This means that we can make more of them if we run out. For instance, if we run out of ethanol, we can grow some more corn and make some more ethanol.

 Other websites 

 Fuel -Citizendium

Category:Fuel