Ethanol Production from Corn — IELTS Writing Task 1 Process Diagram

The diagram illustrates how ethanol fuel (1) --choose-- is producedproduceswas produced from corn. Overall, the process (2) --choose-- consists ofconsist ofconsisted of several stages, beginning with storage and (3) --choose-- endingendended in transport of the finished product.

First, harvested corn (4) --choose-- is storedstoredwas storing and subsequently (5) --choose-- undergoesundergounderwent milling to produce a fine powder. The milled material (6) --choose-- is cookedcooksis boiling with water for about four hours; during this time the mash (7) --choose-- is heatedheatshas heated continuously.

After cooking the mixture (8) --choose-- is cooledcoolscooled and (9) --choose-- is transferredtransfershas transferred to fermentation tanks where yeast (10) --choose-- is addedaddsadded and the mash (11) --choose-- fermentsis fermentingis fermented for approximately 48 hours.

The mixture (12) --choose-- is separatedseparateswas separated into solid by-products and liquid ethanol. The liquid (13) --choose-- undergoesunderwentundergo distillation, which (14) --choose-- lastslastedis lasting around five hours.

After purification, ethanol (15) --choose-- is storedstoredwas stored in tanks and then (16) --choose-- is transportedtransportstransported to fuel stations. The production line (17) --choose-- requiresrequirerequired both mechanical and chemical operations.

Quality control (18) --choose-- is carried outcarries outcarried out at several stages to ensure the fuel (19) --choose-- meetsmeetis meeting regulatory standards. Overall, the diagram (20) --choose-- demonstratesdemonstratedemonstrated a clear step-by-step production procedure.