Biofuels: What is biofuel

Nowadays, people are looking for ways to reduce their carbon footprints, that is to say the amount of fossil carbon that they release into the atmosphere. The fastest growing way to do this is by using biofuels.

Biofuels are fuels that are produced from biological sources such as trees, plants or micro-organisms. They are carbon neutral, because they do not result in fossil carbon being released into the atmosphere. All of the carbon contained in a biofuel was absorbed from the atmosphere by photosynthesis in plants, just a few months or years earlier. This means that when you burn a biofuel, you simply release the carbon back into the atmosphere, and have no overall effect on atmospheric CO2 levels. In contrast, fossil fuels contain carbon that has been locked up underground for millions of years. Burning a fossil fuel increases the level of CO2 in the atmosphere, but it is not balanced out by photosynthesis.

The three biofuels which are most widely used are bioethanol, biodiesel and wood.

Bioethanol can be used in standard gasoline engines with fairly small modifications, provided that it is mixed with normal gasoline. E10 is a mixture of 10% ethanol and 90% gasoline. There are several race cars running on E10 fuel in the prestigious American Le Mans Series. For many years, Brazil has successfully used a mixture of gasoline and bioethanol produced from sugar cane in its cars. E85 is a mixture of 85% bioethanol and 15% gasoline, and is actually a high performance fuel due to the high octane rating of ethanol. Some manufacturers are bringing out cars capable of running on E85, but availability of this fuel is still very limited.

There is some controversy over bioethanol, as it is questionable whether the fossil carbon savings are balanced by the fossil fuel used in its production. Research is still ongoing to make bioethanol from cheap sources such as wood.

Biofuels: What is biofuel

Biodiesel is made from vegetable oils. It can be used in diesel engines, and can be mixed with standard diesel and used in most modern diesel cars with small modifications. Biodiesel use is gradually increasing in Europe, where around 50% of new cars are sold with diesel engines. Again, there is debate as to how much biodiesel can reasonably be produced. Small amounts are being made out of recycled vegetable oil from restaurants.

Wood is a biofuel that humans have used for thousands of years. It can be burned as logs on a roaring fire to heat a home, produce hot water and to cook food. However, there are now modern systems that have brought wood into the 21st century. Automatic boilers have been produced that burn wood pellets to heat a house. The homeowner simply has to tip a bag of wood pellets into a hopper once every two or three days, and the system will do the rest. Alternatively a bulk pellet tank can be installed to feed the system automatically. Modern wood fired boilers are so efficient that the ash container need only be emptied once a month. This is nearly as convenient as using an oil burning boiler, but releases 90% less fossil carbon, even including the fuel used to harvest and transport the wood.

If you wish to reduce your fossil carbon emissions, biofuels are not a total solution. However, they can be used in conjunction with efficiency savings to help reduce your fossil fuel consumption, and shrink your carbon footprint.