Biofuel is any fuel that is derived from biomass. One definition of biofuel is fuel with an 80 per cent minimum content by volume of materials derived from living organism harvested within the ten years preceding its manufacture.

Biofuels was used since the early days of the car industry. Nikolaus August Otto, the German inventor of the combustion engine, conceived his invention to run on ethanol. While Rudolf Diesel, the German inventor of the Diesel engine, conceived it to run on peanut oil. Henry Ford originally had designed the Ford Model T, a car produced between 1903 and 1926, to run completely on ethanol, after surreptitious efforts were successful at thwarting Ford's desires to mass produce electric cars. However, when crude oil began being cheaply extracted from deeper in the soil, cars began using fuels from oil. 1

Biomass is any recent plant or animal organic matter. Coal and oil fossil fuels are fossilised biomass. Biomass energy can be produced from plants, wood, residues (for example sawdust and bagasse, or sugar cane residue, after crushing) and animal wastes. During photosynthesis, solar energy and carbon dioxide are stored in plants. When biomass is burned carbon dioxide and energy are released, which is the reverse of photosynthesis.

If biomass is not used to produce energy in power plants, it naturally decomposes into simple substances and produces heat. Using biomass for energy production is just speeding up a natural process and does not add extra carbon dioxide to the environment. So biomass is a form of renewable energy. Biomass can be used directly (for example, burning wood for heating and cooking). It can be used indirectly by converting it to a liquid or gas fuel (for example, producing ethanol from sugar crops or producing methane, or natural gas, from animal manures).

Traditional biomass use includes wood and charcoal for fuel. Modern biomass use is concerned with finding substitutes for fossil fuels. Agricultural crops, such as sugar cane, corn, sunflower seeds and soya beans, can be grown for use as energy sources called biofuels, which can be used in motor vehicles. These plants are used to make ethanol (an alcohol) in the same way that ethanol is made for alcoholic drinks. The plants are crushed and mixed with yeast, which converts starches to ethanol. This is done commercially in Brazil, the USA and Europe and experimentally in Australia. In the USA, corn (maize) is used to make ethanol and then blended with gasoline to produce ‘gasohol’ to run cars. Some engine modifications are required to use this petrol substitute.2

There are different forms of biofuels which include:

• Methanol, which can also be produced from biomass.
• Biomass to liquid, synthetic fuels produced from syngas. Syngas in turn, is produced from biomass by gasification.
• Ethanol fuel produced from sugar cane is being used as automotive fuel in Brazil. Ethanol produced from corn is being used mostly as a gasoline additive (oxygenator) in the United States, but direct use as fuel is growing.
• Butanol is formed by A.B.E. fermentation (Acetone, Butanol, Ethanol) and can be burned "straight" in existing gasoline engines (without modification to the engine or car), produces more energy and is less corrosive and less water soluble than ethanol, and can be distributed via existing infrastructures.
• Mixed Alcohols (e.g., mixture of ethanol, propanol, butanol, pentanol, hexanol and heptanol, such as EcaleneTM), obtained either by biomass-to-liquid technology (namely gasification to produce syngas followed by catalytic synthesis) or by bioconversion of biomass to mixed alcohol fuels

One widespread use of biofuels is in home cooking and heating. Typical fuels for this are wood, charcoal or dried dung. The biofuel may be burned on an open fireplace or in a special stove. The efficiency of this process may vary widely, from 10% for a well made fire up to 40% for a custom designed charcoal stove. Inefficient use of fuel may be a minor cause of deforestation (though this is negligible compared to deliberate destruction to clear land for agricultural use) but more importantly it means that more work has to be put into gathering fuel, thus the quality of cooking stoves has a direct influence on the viability of biofuels. 3

In Brazil, more than half of the cars sold can use ethanol for fuel, burning 4 billion gallons annually. Oil prices in the 1970s prompted the development of this by-product of sugar into a potentially huge earner for Brazil as demand for cleaner energies boost their exports.4

Biomass has great potential to increase its contribution to commercial energy production. By some estimates, biomass could increase its current share of the energy mix by two-and-a-half times and contribute nearly 50 percent of the world’s energy. Sweden, for example, plans to increase biomass energy production from 20 to 40 percent by 2020 through extending and improving the use of residues from forest and wood processing industries. 5

However there are real concerns about the current rush for biofuels which are leading to:

• mass deforestation in developing countries
• rise in cereal prices and danger of starvation in developing countries
• priority of land use to grow biofuel than crops to eat
• increase in unrest due to food scarcity

Notes

1. http://www.answers.com/biofuel
2. Power for a Sustainable Future, Fact Sheet 10: Biomass Energy, http://www.sustainableenergy.qld.edu.au/fact/factsheet_10.html
3. http://www.answers.com/biofuel
4. P. Brown, ‘Global Warning: The last chance for change,’ Dakini Books NP (2006) p.308
5. UNEP, ‘Natural Selection: Evolving Choices for Renewable Energy Technology and Policy’, UNEP (2000), p.13