You have heard the term biofuel but aren't sure what it means. Biofuel is any fuel that is derived from biomass-recently living organisms or their metabolic by-products, such as manure from cows. It is considered 'green' because it comes from a renewable energy source, unlike other natural resources such as petroleum, coal and nuclear fuels.
Agricultural products specifically grown for use as biofuels include corn and soybeans (primarily in the United States) as well as flaxseed and rapeseed (primarily in Europe).
Waste from industry, agriculture, forestry and households can also be used to produce bioenergy and include straw, lumber, manure, sewage, garbage and food leftovers.
The production of biofuels to replace oil and natural gas is in active development, focusing on the use of cheap organic matter (usually cellulose, agricultural and sewage waste) in the efficient production of liquid and gas biofuels that yield high net energy gain.
There are various current issues with biofuel production and use, which are presently being discussed in the popular media and scientific journals. These include: the "food vs fuel" debate, carbon emissions levels, sustainable biofuel production, deforestation and soil erosion, impact on water resources, human rights issues, poverty reduction potential, biofuel prices, energy balance and efficiency, and centralised versus decentralised production models.
What material can be used to make biofuels? Conventional ethanol is made from sugar cane, corn, and sweet sorghum. Soybean and rapeseed oil are often used to make biodiesel, but coconut, palm, canola and jatropha nut oil are also being used throughout the world.
Trees, grass, agricultural residue, and municipal solid waste can also be converted into biofuels. Cellulose makes up the majority of a plant's structure and can be broken down into sugars, which can then be fermented and made into ethanol. Recent research is making this process less expensive and more energy efficient.
As the world's top producer, Brazil uses sugar cane to make ethanol. Many other developing countries, such as those of southern Africa, produce large amounts of sugar and also have potential to become ethanol producers. The Midwestern United States relies on corn to produce nearly one-quarter of the globe's ethanol, and China is quickly emerging as the third largest ethanol supplier.
Other countries with limited fossil fuel resources are examining the prospect of producing domestic fuel supplies. Thailand has an aggressive policy to make use of tapioca and sugar cane for ethanol production. In response to the recent passage of the EU Biofuels Directive, member countries are ramping up biodiesel production. The Philippines recently mandated incorporation of coconut oil biodiesel into diesel fuel, the first time coconut oil has been used as a motor fuel.
Cars, trucks, and farm machinery can all run on low-volume biofuel blends without any alteration. Current car warranties cover operation with ethanol-blended gas of up to ten percent. Flexible Fuel Vehicles (FFVs) operate on any combination of ethanol and gasoline. FFVs are being sold in the U.S., Brazil, and China. As ethanol has a higher octane, it is used as a gasoline additive to improve vehicle performance. In fact, many international racing teams use ethanol because of its high performance qualities. Biodiesel blends of 20% show similar operation in conventional diesel engines as regular diesel fuel.
Are biofuels the answer for today's energy crisis? It may be too soon to tell but it certainly has been an alternative source in the meantime.
