Biofuels
By definition,biofuels are fuels that are comprised of biological ingredients like plant material.
In order to be used in an automotive engine,plant material has to go through a refining process.
This process turns raw plant material into ethanol.
Both corn ethanol and switch grass fuels come from plants that are replenishable.
That means they can be grown over and over again.
Just like regular gasoline-powered car,biofuels emit carbon dioxide,but up to 94 percent less.