A biofuel is a form of fuel that is produced from renewable organic materials, such as sugar crops, oil seed crops, and animal fats. They are considered to be potential substitutes for carbon-based fuels, i.e. extremely old, biofuels. There are two varieties: plant-based and animal-based.
The plant-based products are fermented sugars which create the fuels like ethanol.
The animal-based products are processed by combining an alcohol with an animal fat in order to create biodiesel.
At present, biofuels are a hot topic in modern society. As carbon-based fuels become more expensive and scarce and political tensions rise, biofuels appear to be a viable replacement and potential source of energy independence. In the United Sates, it has been asserted that most vehicles can use gasoline with up to 10 percent ethanol – the most widely produced and used biofuel. However, consumers take issue with the effect of the ethanol on motors as well as increases in gas prices associated with biofuel production. There are also demands to stop government subsidies for the production of crops for fuel production. Globally, there are issues with the destruction of rainforest for the production of raw material for biofuel, e.g. sugarcane or palm
Likewise, there is controversy as to whether the finite resources necessary for producing biofuels should be allocated to fuel rather than food when an estimated billion people are faced with hunger on a yearly basis. However, this issue is in the process of being solved via the use of waste products for biofuel production, rather than the edible portion of the product. Alternative options, such as the use of algae, are also being explored in an effort to reduce the environmental impact of biofuels.
What role ethanol and other biofuels will play in the future of energy production is uncertain, although the Energy Independence Act of 2007 encourages the production of biofuels to reach 36 billion gallons by 2022. If their use continues to expand, potential benefits include increases in domestic energy productions, a reduction in some air pollutants, the opportunity for a new source of income for farmers, and the possibility that production can be developed in a sustainable manner. Biofuels also emit fewer greenhouse gasses when burned. Conversely, biofuels may result in land-use changes, an increased need for agricultural subsidies, greater use of pesticides, herbicides and fertilizers that can compromise water, soil and air quality, and prices for food crops may increase because of shifts in production.
sources:
https://www.epa.gov/environmental-economics/economics-biofuels
https://ec.europa.eu/energy/en/topics/renewable-energy/biofuels
https://www.nrel.gov/workingwithus/re-biofuels.html
http://www.nationalgeographic.com/environment/global-warming/biofuel/