ONE OF the objectives with 2012 being designated the International Year of Sustainable Energy for All, is to place more emphasis on the use of renewable energy. One of the forms of renewable energy – biofuel, is being given increased attention as options for clean, alternative energy are explored. There are three types of biofuels: ethanol, biodiesel and biogas. Ethanol and biodiesel are used as transportation fuels. Ethanol is used as a substitute for gasoline and biodiesel is used as a substitute for diesel. They are usually combined with the respective petroleum fuels, but can also be used on their own. Although they are usually more expensive than the fossil fuels that they replace, biofuels are cleaner-burning fuels and produce fewer air pollutants.
Ethanol
Ethanol is a clear, colourless, alcohol fuel made from the sugars found in grains such as corn, and barley, as well as potato skins, rice, sugar cane, sugar beets, and yard clippings. Ethanol is a renewable fuel because it is made from plants.
The most common process of making ethanol today is to use yeast to ferment the sugars into alcohol. Sugar crops are the easiest ingredients to convert into alcohol. Brazil, the country with the world’s largest ethanol production, makes most of its ethanol from sugar cane.
Biodiesel
Biodiesel is a fuel made from renewable, domestic resources such as vegetable oils, fats, or greases. To use biodiesel, there is no need to make modifications to a normal diesel engine.
Biofuels & the Environment
Unlike the fuel that is made from petroleum, ethanol and biodiesel are non-toxic and biodegradable; they quickly break down into harmless substances if spilled. However, chemical denaturants are added to ethanol used as fuel to make it undrinkable. Many of the denaturants that are used are toxic, but they are used in relatively small quantities.
Biofuels burn cleaner than petroleum. Burning a gallon of any biofuel produces fewer emissions of carbon dioxide and other air pollutants like particulates, carbon monoxide, sulphur dioxide, and hydrocarbons. However, it does slightly increase emissions of nitrogen oxides.
Using biofuels can be considered carbon – neutral since the plants that are used to make the fuel, e.g., corn, sugar cane, palm oil trees– would absorb carbon dioxide as they grow, and as such would compensate for the carbon dioxide produced when the biofuels are made or are being used.
However, some persons argue that growing plants for fuel is controversial, as the land, fertilisers, and energy used to grow biofuel crops could be used to grow food crops instead. In fact, in some parts of the world, large areas of natural vegetation and forests have been cleared and burned to grow soybeans and palm oil trees to make biodiesel.
In Guyana, the Institute of Applied Science and Technology (IAST) currently operates a plant that converts fresh and used vegetable and animal-derived oils into biodiesel. These oils are supplied by the fast food companies in Guyana. The biodiesel produced by IAST is used to power the vehicles of the Institute. 

Find and circle the renewable resources from which biofuels can be made.
You can share ideas and questions by sending your letters to: ‘Our Earth, Our Environment’, C/o EIT Division, Environmental Protection Agency, Ganges Street, Sophia, GEORGETOWN, or email eit.epaguyana@gmail.com