BIOFUELS

Biofuel (if cultivated, then also called agrofuel or agrifuel) can be broadly defined as solid, liquid, or gas fuel consisting of, or derived from recently dead biological material, most commonly plants. This distinguishes it from fossil fuel, which is derived from long dead biological material.

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.

Biofuels are used globally and biofuel industries are expanding in Europe, Asia and the Americas. The most common use for biofuels is as liquid fuels for automotive transport. The use of renewable biofuels provides increased independence from petroleum and enhances energy security.

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 effect of moderating oil prices, 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.

One of the greatest technical challenges is to develop ways to convert biomass energy specifically to liquid fuels for transportation. To achieve this, the two most common strategies are:

• 1. Wood and its byproducts can be converted into biofuels such as woodgas, methanol or ethanol fuel. Some researchers are working to improve these processes.

2.To grow sugar crops (sugar cane, and sugar beet), or starch (corn/maize), and then use yeast fermentation to produce ethanol (ethyl alcohol).

• 3. To grow plants that (naturally) produce oils, such as oil palm, soybean, algae, or jatropha. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine, or the oils can be chemically processed to produce fuels such as biodiesel.

More on http://en.wikipedia.org/wiki/Biofuel