distillation problem
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The requirement of the ethyl acetate distillation process is to remove all the water in the mixed liquid of ethyl acetate and water and recover the ethyl acetate. It is required that the water content in the distilled ethyl acetate is less than 0.30%. When a large amount of ethyl acetate is steamed out, the temperature is about 78 degrees, and the temperature of the still during distillation is 78-80 degrees. The boiling point of water is 100 degrees. Why can the kettle temperature of 78 degrees steam out almost all the water when ethyl acetate is distilled?
Ethyl acetate and water can form an azeotrope, which occurs at around 70°C. When an azeotrope is formed, the boiling point is lower than the boiling points of the two pure substances. The mole fraction of water in the azeotropic composition is about 35% and that of ethyl acetate is about 65%. Therefore, extraction agent must be added to separate. :)
I did this experiment when I was in school, but I have almost forgotten it now.
The binary azeotrope formed by ethyl acetate and water, the content of ethyl acetate is 93.9%, the water is 6.1%, and the azeotropic point is 70.4°C. Laboratory refining method: heat and reflux a mixture of industrial grade ethyl acetate, 100ml acetic anhydride, and 10 drops of concentrated sulfuric acid for 4 hours, and then distill. The purity of the final product can reach 99.7%, and the boiling point is 77°C. But in industry, only extractive distillation is used.
Azeotrope should be taken from the top of extractive distillation