How are biofuels produced?

To answer the question "How are biofuels produced?" it's helpful to understand the difference between biofuels and fossil fuels, as well as to gain insight into different biofuel technologies. Because of the tremendous growth in biofuel industries all over the world, it's just a matter of time before each nation must assess and even improve how biofuels are produced.

What Is Biofuel?
Biofuel is any combustible fuel that can be extracted from living materials, such as animals or plants. Examples include ethanol (the fermentation of yeast in high sugar crops) and vegetable oil (liquids derived from plant life). It can also be taken from living things that have only recently expired. It is different from fossil fuels, which are derived from organisms long gone, such as petroleum, coal or natural gas. The two main biofuels are biodiesel and bioethanol.

Biodiesel
Biodiesel usually comes from vegetable oil, animal fat or waste cooking oil. The biodiesel is produced via a process called transesterification, where a chemical reaction occurs. Alcohol reacts with fatty acids to form a layer of glycerin and one of ester. The glycerin is a byproduct that is used elsewhere, such as in cosmetics. The ester, the biodiesel, is purified and often distilled to become a commercial fuel.

Bioethanol
When sugar ferments, it can create a bioethanol fuel. Crops like corn, maize, sorghum plants and certain grasses are considered energy crops or fuel crops. To make this clear liquid, enzymes and acids are added to a mass of plant life, where the cell walls of the matter are broken down. Yeasts and heat act as a catalyst for this process. The result of this chemical process is sucrose sugars, which are then allowed to ferment. After fermentation is complete, the process yields ethanol.

The Future Of Biofuel
Many countries are putting up resources to research and develop more efficient and cost-effective methods for producing biofuels. As better methods are developed and commercialization takes place, biofuels can eventually become a viable alternative to, and indeed may someday replace, the fossil fuels that run the world's vehicles.

Source : http://www.life123.com/home-garden/green-living/biofuels/how-are-biofuels-produced.shtml