The provided diagram illustrates the cyclical process of producing biofuel, specifically ethanol, from plant matter. Overall, the production of ethanol is a continuous loop that begins with the growth of vegetation and ends with the release of carbon dioxide through the combustion of fuel in various modes of transport.
The process commences with plants and trees growing by absorbing energy from sunlight and carbon dioxide. Once mature, these plants are harvested and undergo a pre-processing stage. Following this, the material is broken down into cellulose, which is then subjected to further processing. During this phase, the cellulose is converted into sugars. Microbes are subsequently added to these sugars to facilitate the production of ethanol.
Once the ethanol is produced, it is distributed for use in various transport sectors, including cars, trucks, and airplanes. The combustion of this biofuel in these vehicles results in the emission of carbon dioxide. This released carbon dioxide completes the cycle by returning to the atmosphere, where it is once again absorbed by growing plants and trees, thereby sustaining the cycle of biofuel production.