The diagram demonstrates how ethanol is produced.
Biofuel is made in a cyclical process which is partly natural and partly synthetic. It comprises six steps in which sunlight and carbon dioxide are transformed into ethanol to be used in operating various vehicles.
First, trees and plants absorb carbon dioxide and sunlight in order to convert them into energy by which they grow. Second, they are harvested by farmers using tractors, and the product is broken down into cellulose using a machine, this is called pre-processing. After that, cellulose is processed in the laboratory to yield sugars. Finally, ethanol is produced by adding microbes to said sugars.
Ethanol is used to fuel cars, trucks, and planes, which emit carbon dioxide, which is re-absorbed by plants and the process goes on.