Band 9: You should spend about 20 minutes on this task. The diagram below shows how a biofuel called ethanol is produced. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

The diagram illustrates the process of producing ethanol, a type of biofuel, from plants and trees.

Overall, ethanol production is a cyclical process involving the growth of plants, the extraction and processing of cellulose, and the eventual use of ethanol as a fuel. In addition, carbon dioxide released during later stages is reabsorbed by plants during growth, creating a continuous cycle.

Initially, plants and trees grow by using energy from sunlight together with carbon dioxide from the atmosphere. Once fully grown, the crops are harvested and sent for pre-processing. During this stage, some carbon dioxide is emitted. The raw material is then converted into cellulose before being transported to a processing plant.

Next, the cellulose undergoes industrial processing, resulting in the production of sugars. Microbes are subsequently added to these sugars in order to produce ethanol.

In the final stage, ethanol is used as a fuel for vehicles such as cars, trucks and aircraft. The combustion of this fuel releases carbon dioxide back into the atmosphere, which is then absorbed by plants and trees, thereby completing the cycle.