As the term suggests, bio-fuels are fuels that are formed when biological matter decomposes. The bio-fuels are mostly derived from plants. Bio-fuels exist in all the three states of matter: solid, liquid, and gas.

They differ from fossil fuels in several aspects: 1. Fossil fuels are created over millions of years while biofuels can be made very quickly. 2. When compared to fossil fuels, biofuels tend to create less air pollution. 3. Because of their regeneration time, biofuels are considered much more ‘renewable’.

Bio-fuels have been categorized into four types: first generation, second generation, third generation, and fourth generation.

The 1st generation come from farm crops and animal fats – vegetable fats, starch, sugar and animal oils. Examples of these biofuels are biogas, biodiesel, and vegetable oil.

The 2nd generation of biofuels are derived from waste biomass. This would include oil, alcohols and diesels made from things such as felled trees.

The 3rd generation comes from algae. Algae can be farmed on a large scale for this purpose, and the fuel that algae produces is usually very environmentally friendly.

The bio-fuels in the fourth generation are derived by a method in which micro-organisms are raised to work with carbon dioxide to generate fuel.

Advantages of biofuels include: 1. They reduce the burden on fossil fuels which will one day run out. 2. They are eco-friendly, unlike many bio fuels, and will help reduce carbon dioxide emissions. 3. They can be very cost effective when used correctly.

Biofuels also have some disadvantages. These include: 1. The problem with biofuel crops taking up farm land in places where food is at a premium. Many people believe that food should always take priority over energy. 2. Many acres of land will be farmed as our dependence on these fuels begins to grow.