The picture illustrates the cyclic process of producing ethanol, a kind of biofuel.
Overall, there are nine steps combining manufacturing and natural processes, starting with harvesting trees and ending with releasing ethanol from vehicles, then absorbing it into trees.
The process commences with cutting out trees, following this, they are crushed the small pieces of wood by a machine. This step is called pre-processing. These pieces become cellulose before adopting the processing which uses chemical substances to adjust from cellulose to sugars. After this stage is finished, adding microbes to sugars creates ethanol to provide the diversity of vehicles that use it to operate.
Once biofuel production has finished, vehicles such as planes, trucks, and cars reveal the amount of carbon dioxide in the environment. Once the final stage has been completed, carbon dioxide from transportation and human activities plus energy as sunlight accumulates in plants and trees that are growing.