IELTS Academic Writing Task 1/ Graph Writing – Diagram:
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.
Write at least 150 words.
Biofuel production: how ethanol is made
Model Answer 1:
The diagram illustrates how ethanol, a biofuel, is produced in a continuous cycle that connects plant growth, industrial processing, fuel use, and carbon dioxide emissions.
Overall, the cycle begins with plants absorbing sunlight and carbon dioxide, then moves through several stages of processing and fermentation to create ethanol, which is used in vehicles. The carbon dioxide released during combustion is recaptured by plants, completing the circle.
In detail, plants and trees grow by harnessing energy from sunlight and carbon dioxide (CO₂). Once harvested, this biomass undergoes pre-processing to break it down into cellulose. The cellulose is then chemically treated to form simple sugars. After that, microbes are added to these sugars, triggering a fermentation process that yields ethanol. Finally, the ethanol is used as a fuel in cars, trucks, and aeroplanes. When burned, it emits carbon dioxide, which is released into the atmosphere. This CO₂ is then taken up again by new plant growth, which feeds into the start of the cycle, showing a sustainable, closed-loop system.
Sample Answer 2:
The diagram shows the stages involved in producing ethanol fuel from plants, from the growth of raw materials to the final combustion of the fuel.
Overall, the process is circular and renewable. Plants are grown, converted into ethanol through several steps, and the fuel is then burned, releasing carbon dioxide that plants absorb again during the next growth cycle.
The process begins with plants capturing sunlight and absorbing carbon dioxide from the air. Once they are fully grown, they are harvested and taken for processing. At this stage, the plant material is broken down so that cellulose can be extracted. This cellulose is then treated chemically to produce simple sugars.
Next, these sugars are fermented by microorganisms, which naturally convert them into ethanol when microbes are added to them. After fermentation, the mixture is refined so that clean, usable ethanol fuel can be obtained. The final product is transported to various sectors for use, such as in vehicles and machinery. In the final stage, ethanol is burned as fuel. Although this releases carbon dioxide, the gas is reused by plants in the first stage, completing a continuous and environmentally friendly cycle.