Alternative Fuels

Wild Grass Biofuel - Cars can eat grass too!

2:32 PM, 4/9/2007 .. Posted in Bio Fuels .. 1 comments .. Link

Wild Grass is emerging as one of the hot potential biofuel sources offering a number of advantages over other plant based biofuels including low water requirement, it's carbon negative, it's not a food source and can be grown on degraded land that is unsuitable for food production.

In field tests the grasses have shown to take in more carbon dioxide from the atmosphere than was released from the fuel used to grow and process them.

Reports also indicate that it can produce yields between five and 10 times greater than corn.

I'm not a great fan of genetic modification but if wild grass could be engineered to grow in dry or saline soil then it becomes very attractive. There is a lot of negatives to using corn or sugar for biofuel production due to their water requirements and taking resources away from the food production system.

Currently I could not see how Australia could be a part of the biofuel solution having such little sustainable and economically viable farmland for food production, low water resources and being so susceptible to drought. The right strain of wild grass makes things interesting if it could be used on non-productive land, not require huge water resources and could run alongside with agricultural food production and not in competition.

More info:
More about Miscanthus - http://bioenergy.ornl.gov/papers/miscanthus/miscanthus.html
US Dept. of Agriculture - Genetic Snapshots Help Brighten Switchgrass’s Future
Green Car Congress - Mixed Prairie Grasses Are Better Biofuel Source
New Scientist - Big risks of the biofuel revolution

Biofuels - ethanol

4:17 PM, 19/9/2006 .. Posted in Bio Fuels .. 2 comments .. Link

Liquid fuel can be made from biomass which has a high sugar content. This is done by fermenting it to produce alcohol (ethanol). Fermentation is the process whereby yeasts digest sugar as food and make alcohol as a waste product. This is what happens when beers and wines are made. Sugar in large amounts comes from plants such as sugar-cane, corn, sugar beet, cereals, wood and even seaweed. After harvest, the sugar is taken out of these plants, usually by crushing them. Yeast is added to the sugar solution and after several days the sugar has been converted to ethanol. The ethanol is then taken out of the solution.

The ethanol can be added to petrol. In 2004, ethanol was blended into approximately one-third of America's gasoline. But it is in Brazil that the greatest effort has been made to produce alcohol as fuel. All gasoline sold in Brazil contains at least 26 percent ethanol, but motorists driving flexible-fuel cars have the option of filling up with pure ethanol, or E100, which currently is selling for about half the price of the blend. Brazil is already the largest producer and exporter of ethanol, sending half a billion gallons a year to several countries around the world.

The Australian Government has limited the level of ethanol in petrol in Australia to a maximum of 10%, or E10. Most new and many older vehicle models can run on ethanol blended petrol, although you need to check with the vehicle maufacturer.

Other crops which have a high oil content can also supply liquid fuels for diesel engines. These include soya, coconut, palms and sunflowers. These are crushed to squeeze out their oil content. This oil can then be used in diesel engines without any further processing and is used to power trucks, tractors and electricity generators.

Biogas

3:36 PM, 19/9/2006 .. Posted in Bio Fuels .. 1 comments .. Link

Gas can be made in other ways from other materials, notably sewage and waste. Gases are given off when anything organic dies and decomposes. One of these gases is methane, which is flammable and can be used as a fuel. The things at work in decomposition are bacteria. To work properly these bacteria must be in a warm and airless environment.

Biogas digesters are designed to create these conditions. A digester is made up of a tank into which sewage or sorted garbage is pumped. It may be necessary to heat this mixture to the correct temperature, or to put the bacteria that produce the gas into the tank. The bacteria then digest the organic matter, giving off methane in the process. The methane is then carried through pipes to a gasholder. This may be another tank, or a giant plastic balloon. This gas can be used as it is, or it can be used to drive generators that produce electricity. A further advantage of producing biogas in this way is that the solid waste left in the digester makes an excellent fertilizer for food crops.

Biogas digesters are already an important source of energy in a number of countries. This form of bioenergy is particularly useful to small farming communities. This is because they have large amounts of animal dung and other organic wastes available.

In the city of Linkoping in Sweden, the whole town runs on methane-rich clean fuel created by animal waste. Most of the town's buses, taxis, even the train run on biogas to service the population of 100,000. Currently 25% of energy use in Sweden is from biomass. By 2050, Sweden plans to become a fossil-fuel free country.

Navigation

Get this widget!

Links

Green Vehicle Guide
Australian BioFuel Users
Fuel Cell Institute
GreenHouse.gov.au
Directory of Energy in Australia
RSS feed for Alternative Fuels