The diagram illustrates the process of making ethanol.
Overall, biofuel production is a man-made, recurring cycle which consists of 6 steps with three primary stages: harvesting and pre-processing plant materials, chemically converting them into ethanol, and using the fuel for transportation.
At the start of the process, plants and trees grow as they absorb energy from sunlight and carbon dioxide. Once fully grown, they are mechanically harvested before being put into a pre-processing machine, which breaks them down into smaller components to extract cellulose.
The second stage begins with the cellulose being transported to a laboratory, where it is chemically processed into sugars. Microbes are subsequently added to these sugars to facilitate fermentation, resulting in the creation of ethanol.
Finally, the third stage involves the utilization of the produced ethanol as fuel for various modes of transportation, including cars, trucks and airplanes. During the use of ethanol as fuel, carbon dioxide is released back into the atmosphere, which is then reabsorbed by plants and trees, continuing the cycle.