Sample answer for Test 3: Writing Task 1 C.19
You have approximately 20 minutes to complete 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.
Your report should comprise a minimum of 150 words.
Sample Answer:
The diagram illustrates the cyclical process involved in producing ethanol, a type of biofuel, from plant materials.
Overall, the biofuel production cycle consists of three primary stages: harvesting and pre-processing plant materials, chemically converting them into ethanol, and utilizing the fuel for transportation, with the cycle then recommencing.
At the outset of the process, plants and trees undergo growth, fueled by sunlight and absorbing carbon dioxide from the atmosphere. Once matured, they are mechanically harvested and fed into a pre-processing machine. This machine breaks down the plant materials into smaller components, primarily cellulose, through a series of mechanical and chemical processes.
Moving to the second stage, the extracted cellulose undergoes transportation to a laboratory, where it undergoes chemical processing to convert it into sugars. These sugars are crucial for the subsequent fermentation process. Microbes, introduced into the sugars, facilitate fermentation, resulting in the production of ethanol as a byproduct.
Finally, the ethanol produced in the previous stage is utilized as a fuel source for various modes of transportation, such as cars, trucks, and airplanes. During this utilization phase, ethanol undergoes combustion, releasing carbon dioxide back into the atmosphere. This carbon dioxide is then reabsorbed by plants and trees, restarting the cycle.
In conclusion, the production of ethanol from plant materials involves a cyclical process encompassing harvesting and pre-processing, chemical conversion into ethanol through fermentation, and utilization as a fuel source for transportation. This process highlights the sustainability of biofuels in reducing carbon emissions by maintaining a continuous cycle of carbon dioxide absorption and release.
(Word count: 254)
