Biofuels in general

Posted by Krzysztof Lis on March 13, 2008

Biofuels are all the fuels that are made of biomass (all biological matter, produced by living organisms). They are a renewable energy source, contrary to fossil fuels like oil, natural gas, coal or uranium. Some scientists use term biofuel only referring to fuels that in more than 80% (volumetric) are made of biomass harvested 10 years prior to producing that fuel.

Biofuels are a way of accumulating solar energy. Solar radiation is used by plants in a process called photosynthesis. The energy bound within a biomass can be stored almost infinitely long and is not dangerous.

Biofuels are produced in solid (e.g. wood logs and chips, briquetted straw), fluid (bioethanol, biodiesel) or gaseous (wood gas, biogas) form. They can be used to fuel internal combustion engines, boilers, furnaces and other devices.

In Europe, linum (flax) and rapeseed are main stock used for producing biofuels. In America people use mostly corn and soya beans, in other parts of the world – hemp. Biodegradable residue of industrial or agricultural origin, forest residues, even biodegradable household garbage can be used to manufacture biofuels of some kind.

Biofuels can be used for centralised and distributed heat and power generation. In 2005 of all global energy usage 15% was derived from biofuels. Most of that number was wood used for heating and cooking in developing countries.

Biofuel is an alternative considered to replace petroleum gas (gasoline or petrol). Most transportation vehicles are powered by internal combustion engines. These engines require clean burning fuels, which are generally in liquid and gaseous form (e.g. Compressed Natural Gas). Liquids are more portable because they have higher energy density, and they can be pumped, which makes handling easier. This is why most biofuels suitable for using in transportation are liquids.