Band 8.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 8.0 · Cambridge IELTS 19 · 2026-08-17

IELTS Writing Task 1 question

 

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.

Student answer (Band 8.0)

The diagram illustrates the cyclical process of producing the biofuel ethanol, and shows how carbon dioxide is both used and released at different stages.

Overall, the production of ethanol is a closed-loop system with 6 main stages. It begins with the growth of plants using sunlight and carbon dioxide, and ends with the use of ethanol as fuel, which in turn releases carbon dioxide back into the atmosphere to be reused by plants. The process involves both natural and industrial steps, including harvesting, pre-processing, and microbial fermentation.

In the first stage, plants and trees grow by absorbing energy from sunlight and carbon dioxide. Once mature, they are harvested using machinery. The harvested biomass then undergoes pre-processing, where it is broken down into small particles, and cellulose is extracted.

Next, the cellulose is sent for processing in an industrial facility. During this stage, it is converted into sugars. Microbes are then added to these sugars to produce ethanol through fermentation. This is the key transformation point in the cycle.

The final product, ethanol, is used as a fuel source for various forms of transport, including cars, trucks, and airplanes. A notable feature is that when ethanol is burned as fuel, it releases carbon dioxide. This carbon dioxide is then reabsorbed by growing plants, thereby completing the cycle and allowing the process to begin again.

In comparison to fossil fuels, this system is circular rather than linear because the carbon dioxide emitted during fuel use is not a net addition to the atmosphere, but is instead recycled by plants for the next round of biofuel production.

AI examiner evaluation

Task Achievement / Task Response — Band 8.0

The response is excellent. You have clearly identified the main features of the process and provided a logical summary. The overview effectively captures the cyclical nature of the system, which is a key requirement for this type of diagram. You have successfully integrated the information regarding carbon dioxide usage and release, making relevant comparisons between the biofuel cycle and fossil fuels. All stages of the process are described accurately, and the information is well-supported by the details provided in the diagram. You have fully addressed all parts of the task with a clear and professional tone.

Coherence and Cohesion — Band 8.0

The essay is logically organized with a clear progression of ideas. Each paragraph focuses on a specific aspect of the process, moving from the introduction and overview to the detailed stages and finally the comparison. Cohesive devices such as 'In the first stage', 'Next', and 'The final product' are used effectively to guide the reader through the sequence. The use of referencing, such as 'This is the key transformation point', helps maintain flow. Paragraphing is used appropriately to separate the different phases of the process, ensuring the text is easy to follow and coherent throughout.

Lexical Resource — Band 8.0

You demonstrate a wide and precise range of vocabulary appropriate for an academic report. Terms such as 'cyclical process', 'closed-loop system', 'biomass', 'microbial fermentation', and 'net addition' are used accurately and naturally. The language is sophisticated and contributes to the clarity of the explanation. There are no noticeable errors in word choice or collocation, and the vocabulary is well-suited to the technical nature of the task. You have successfully used less common items to describe the industrial and natural stages of the process with precision.

Grammatical Range and Accuracy — Band 8.0

The response displays a high level of grammatical control. You have used a variety of complex sentence structures, such as 'The diagram illustrates... and shows how...', and '...because the carbon dioxide emitted during fuel use is not a net addition...'. The majority of your sentences are error-free, and the punctuation is used correctly to manage the flow of information. There is a good balance between simple and complex structures, and the tense usage is consistent throughout the description of the process. The writing is fluent and demonstrates a high degree of accuracy.

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