The provided diagram illustrates the process in which a biofuel named ethanol is produced
Overall, it is apparently that the manufacture of ethanol involves three essential stages including the pre-processing step, then the processing stage and finally the usage of ethanol.
To start with, plants and trees require energy to grow, which they obtain from sunlight and carbon dioxide. After these crops are harvested, they are moved to the pre-processing phase where cellulose is extracted. This chemical is used in the main processing stage to produce sugars that we usually eat. Once microbes are added to that sugars, it becomes ethanol for further use.
The cycle continues with ethanol becomes fuel which is used by three different means of transprort including private vehicles, lorries and planes. Although they serve various purposes, they are all emit carbon dioxide into the environment. This CO2 is then absorded by plants and trees, restarting the process.