Biofuels are renewable fuels that derive from biomass sources. The biofuel list includes solid biomass, liquid fuels and various other biogases.
The most frequently used biofuel is ethanol. Ethanol is not only used as the replacement for gasoline but also to fuel bioethanol fireplaces. Ethanol fuel is widely used in Brazil and in the United States, these two countries are also the world's largest ethanol producers.
The second most commonly used biofuel worldwide (and the most common biofuel in Europe) is biodiesel. Biodiesel is made from vegetable oils, animal fats or recycled greases. Biodiesel can be used alone, or blended with petrodiesel. The pure biodiesel (B100) is the diesel fuel with the lowest amount of greenhouse gas emissions.
First generation biofuels refers to biofuel production from food crops, second generation biofuels refers to biofuel production from non-food crops such as waste, while third generation biofuels refers to biofuel from algae. Second and third generation biofuels are often called "advanced biofuels". The first generation biofuels are the subject of fuel vs. food debate because it doesn't seem logical (and ethical) to use food crops to produce fuel when there are close to billion hungry people in the world.
Though biofuels are connected with CO2 emissions more than other renewable energy sources they are still much more environmentally friendly energy option compared to fossil fuels. Some even refer to them as being carbon neutral, though this doesn't have to be always right. In any case, what is important is to ensure sustainable biofuel production.
Biofuels can be grown and produced domestically which means that biofuel production can significantly reduce the dependence on expensive foreign oil import, thus improving energy security and energy independence.
The development of biofuel industry can also be a significant job creator. US ethanol industry, for instance, employs more than 210,000 people.
Biofuels have the potential to solve energy problems in developing countries by providing these countries an alternative to using coal (usually the most popular energy source to generate electricity in developing countries).