BIOFUEL

Biofuel is any fuel that is derived from biomass recently living organism or their metabolic by products, such as manure from cows. It is renewable energy source, unlike other natural resources suchas petroleum, coal and nuclear fuels.
One definition of biofuel is any fuel with an 80% minimum content by volume of materials derived from living organism harvested within the ten years preceding its manufacture.
like coal and petroleum, biomass is form of stored solar energy. The energy of the sun is "captured" thriugh the process of photosynthesis in growing plants. One advantage of biofuel in comparison to most other fuel types is that the energy within biomass can be stored for an indefinite time period and without any danger.
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 which yield high net energy gain. The carbon in biofules was recently extracted from atmospheric carbon dioxide by growing plants, so burning it does not result in a net increase of carbon dioxide in the Earth's atmosphere. As a result, biofuels are seen by many as a way to reduce the amount of carbon dioxide released into atmosphere by using them to replace nin renewable sources energy. Noticeable is the fact that the quality of timber or grassy biomass does not have a direct impact on its value as an energy-source.

HISTORY

Biofuel was used since the early days of the car industry. Otto Von Nicklaus, the inventor of the combustion engine, conceived his invention to run on ethanol. While Rudolf Diesel, the inventor of the combustion engine, conceived it to run peanut oil. The Ford Model T, a car produced between 1903 and 1926 used ethanol. However, whwn crude oil began being cheaply extracted from deeper in the soil ( thanks to drilling starting in the middle of the 19th century ), cars began using fuels from oil. Then with the oil shock of 1973 and 1979, there was an increase interest from governments and academic in biofuels. However, interest decreased with the counter-shock of 1986 that made oil prices cheaper again. But since about 2000 with rising oil prices, concerns over the potential oil peak, greenhouse gas emissions ( Global warming ), and stability in the Midle East are pushing renewed interest in biofuels. Government officials have made statements and given aid in favour of biofuels. Foe example, U.S.president Geoorge Bush said in his 2006 State of Union speech, that he wants for the United States, by 2005, to replace 75% of the oil coming from the Middle East.

APLICATIONS OF BIOFUELS

One widespread use of biofuels is in home cooking and heating. Typical fuels for this arewood, charcoal or dried dung. The biofuel may be burned on an open fireplace or in a special stove. The efficiency of this may very widely, from 10% for a well made fire ( even less if the fire is not made carefully ) up to 40% for a custom designed charcoal stove. Inefficent use of fuel may be a minor cause of deforestation( through 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.

"American homeowners are turning to burning corn in special stoves to reduce their energy bills. Sales of corn-burning stoves have tripled this year [...] Corn-generated heat costs less than a fifth of the current rate for propane and about a third of electrical heat".

A. Direct electricity generation

The methane in biogas is often pure enough to pass directly through gas engines to generate green energy. Anaerobic digesters or biogas powerplants convert this renewable energy source into electricity. This can either be used commercially or on a local scale.

B. Use on farms

In Germany small scale use of biofuel is still a domain of agricultural farms. It is an official aim of the German government to use the entire potential of 200,000 farms for the production of biofuel and bioenergy. (Source: VDI-Bericht "Bioenergie - Energieträger der Zukunft".

C. Home use

Different combustion-engines are being produced for very low prices lately . They allow the private house-owner to utilize low amounts of "weak" compression of methane to generate electrical and thermal power (almost) sufficient for a well insulated residential home.

D. Rolling Network

Although decentralised biofuel production is possible the so called island operation bears problems with capacity and load balancing. In case vehicles for commuting and social or procurement trips may be used to transport energy we have a so called rolling network. We expect a higher efficiency with wood based biogas which may be purified in a home filling station and released into the natural gas network at work or special receiving gas stations. This kind of business is not bound to constant delivery amounts but very flexible in both directions. Ie. also gas refilling is possible if the wood gas production is low at the moment or the distance travelled was high. With so called plug in hybrid electric vehicles in theory it would be also possible to carry energy produced underway to work or to home and feed it into the grid. But this is less efficient and also less probable.

EXAMPLES OF BIOFUELS

A. Biologically produced alcohols

Biologically produced alcohols, most commonly ethanol and methanol, and less commonly propanol and butanol produced by the action of bacteria — see alcohol fuel.

• Methanol, which is currently produced from natural gas, can also be produced from biomass — although this is not economically viable at present. The methanol economy is an interesting alternative to the hydrogen economy.
• 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 as a gasoline additive (oxygenator) in the United States. Cellulosic ethanol is being manufactured from straw (an agricultural waste product) by Iogen Corporation of Ontario, Canada. ETBE containing 47% Ethanol is currenttly the biggest biofuel contributor in Europe.
• Butanol is formed by A.B.E. fermentation (Acetone, Butanol, Ethanol) and experimental modifications of the ABE process show potentially high net energy gains with butanol being the only liquid product. Butanol 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 Ecalene^TM), obtained either by biomass-to-liquid technology (namely gasification to produce syngas followed by catalytic synthesis) or by the MixAlco Process.
• GTL or BTL both produce synthetic fuels out of biomass in the so called Fischer Tropsch process. The synthetic biofuel containing oxygen is used as additive in high quality diesel and petrol.

B. Biologically produced gases

Biogas is produced by the process of anaerobic digestion of organic material by anaerobes. Biogas can be produced either from biodegradable waste materials or by the use of energy crops fed into anaerobic digesters to supplement gas yields.

Biogas contains methane and can be recovered in industrial anaerobic digesters and mechanical biological treatment systems. Landfill gas is a less clean form of biogas which is produced in landfills through naturally occurring anaerobic digestion. Paradoxically if this gas is allowed to escape into the atmosphere it is a potent greenhouse gas.

C. Biologically produced gases from wastes

Biologically produced oils and gases can be produced from various wastes:

• Thermal depolymerization of waste can extract methane and other oils similar to petroleum.
• Pyrolysis oil may be produced out of biomass, wood waste etc. using heat only in the flash pyrolysis process. The oil has to be treated before using in conventional fuel systems or internal combustion engines (water + pH).
• One company, GreenFuel Technologies Corporation, has developed a patented bioreactor system that utilizes nontoxic photosynthetic algae to take in smokestacks flue gases and produce biofuels such as biodiesel, biogas and a dry fuel comparable to coal .

D. Biologically produced oils

Biologically produced oils can be used in diesel engines:

• Straight vegetable oil (SVO).
• Waste vegetable oil (WVO) - waste cooking oils and greases produced in quantity mostly by commercial kitchens
• Biodiesel obtained from transesterification of animal fats and vegetable oil, directly usable in petroleum diesel engines.