Biofuels

Biofuel is any type of fuel that has been derived from biomass (recently living organisms or their by-products), such as crops, waste food and manure. Unlike other natural resources such as petroleum, coal and nuclear fuels, biofuel is a renewable energy source. Example include biodiesel, bioethanol and biobutanol.

Biofuel may be obtained from the by-products of other industrial, agricultural or household processes, such as straw, timber, waste vegetable oil, manure, sewage, rice husks, biodegradable waste and food leftovers. It may also be acquired from specifically grown products, such as flaxseed and rapeseed (Europe), maize and soybeans (North America), palm oil (South-East Asia) and sugar cane (Brazil).

In general, biofuels are blended in with traditional fossil fuels in small amounts - usually about 5-20%. This requires no modification to the vehicle's engine. However, in warm climates, straight vegetable oil may be used in some older diesel engines, whilst bioethanol is commonly used in high percentages (up to 100%) in modified engines in Brazil, Argentina and Sweden.