BioFuel

Bio-energy" redirects here. For the term bio-energy in the context of non-mechanist philosophy or alternative medicine, see Vitalism. For articles on specific fuels used in vehicles, see Biogas, Bioethanol, Biobutanol, Biodiesel, Straight vegetable oil, and Wood gas generator.

Biofuel (if cultivated, then also called agrofuel) is a basic abbreviation of biorganic fuel. This is a scientific name for any plant or animal substance that can burn (combustible (fuel) organism (organic) of two types (bi-), plant and animal). Biofuel is an alternative considered to replace petroleum gas (gasoline or petrol). Most transportation vehicles require high power density provided by internal combustion engines. These engines require clean burning fuels, which are generally in liquid form, and to a lesser extent, compressed gaseous phase. Liquids are more portable because they have high energy density, and they can be pumped, which makes handling easier. This is why most transportation fuels are liquids.

Non-transportation applications can usually tolerate the low power-density of external combustion engines, that can run directly on less-expensive solid biomass fuel, for combined heat and power. One type of biomass is wood, which has been used for millennia in varying quantities, and more recently is finding increased use. Two billion people currently cook every day, and heat their homes in the winter by burning biomass, which is a contributor to man-made climate change global warming. The black soot that is being carried from Asia to polar ice caps is causing them to melt faster in the summer. In the 19th century, wood-fired steam engines were common, contributing significantly to industrial revolution unhealthy air pollution. Coal is a form of biomass that has been compressed over millennia to produce a non-renewable, highly-polluting fossil fuel.

Wood and its byproducts can now be converted into biofuels such as woodgas, methanol or ethanol fuel. Biofuel is considered by some as a means of reducing greenhouse gas emissions and increasing energy security by providing an alternative to fossil fuels. However, In October 2007, Nobel Laureate Paul Crutzen published findings that the release of Nitrous Oxide (N₂O) from rapeseed oil, and corn (maize), contribute more to global warming than the fossil fuels they replace. However, the Crutzen paper goes on to say that crops with less nitrogen demand, such as grasses and woody coppicing will have positive but lower climate impacts. In February 2008, two articles were published in Science concluding that clearing land for biofuel production produce twice as much greenhouse gas than the U.N. IPCC had previously estimated.

Biofuels are used globally
Biofuel industries are expanding in Europe, Asia and the Americas. The most common use for biofuels is automotive transport (for example E10 fuel). Increased American and European demand has led to clearing land for Palm Oil plantations. Locations such as Indonesia are subject to deforestation and the accompanying displacement of indigenous peoples. In some areas use of pesticides for biofuel crops are disrupting clean water supplies.

Biofuel can be theoretically produced from any (biological) carbon source. The most common by far is photosynthetic plants that capture solar energy. Many different plants and plant-derived materials are used for biofuel manufacture. The greatest technical challenge is to develop ways to convert biomass energy specifically to liquid fuels. To achieve this, the two most common strategies are:

• To grow sugar crops (sugar cane, and sugar beet), or starch (corn/maize), and then use yeast fermentation to produce ethanol (ethyl alcohol).
• To grow plants that (naturally) produce oils, such as algae, or jatropha. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine. The oils can also be chemically processed to produce biodiesel.

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Ditulis oleh William Perkasa pada tanggal Monday, March 24, 2008