Separation of ternary azeotrope systems
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How can a mixture of 50% ethanol, 20% xylene, and 30% water be separated on a large scale in a factory? We considered adding water to precipitate xylene and then sending it to a distillation column, but the precipitation effect was not significant; moreover, a large amount of xylene ended up being carried out at the top of the distillation column
Just add an evaporator in front of the distillation tower
What is this operation? Should we do simple distillation first?
After simple distillation, a small amount of about 5% xylene remains
After simple distillation, all materials enter the distillation tower in vapor form; controlling the heat source and reflux ratio in the distillation tower is sufficient
Personally, I think it’s better to wash it with water first and then put it in the tower
Combining water extraction with distillation should be no problem; if needed, I can help you prepare a plan first
Names of pure components or binary azeotropes: Ethanol-toluene, Ethanol-water, Ethanol, Toluene-water, Water, Toluene. Boiling point or azeotopic temperature at atmospheric pressure (°C): 76.7, 78.1, 78.4, 84.1, 100, 110.8. Composition of binary azeotropes at atmospheric pressure (wt%): Ethanol 68.0, Ethanol 95.5, ----; Toluene 80.1, -----, -----. In the three-component system of ethanol, toluene, and water, three binary azeotropes are formed. The boiling points of these azeotropes are very close to that of ethanol, making separation difficult using conventional distillation methods; freezing and crystallization techniques also present challenges for separation. It is recommended to first use the pervaporation membrane method to separate and remove water, and then apply adsorption separation to the ethanol-toluene mixture in order to obtain ethanol and toluene components. The diameter of an ethanol molecule is 0.51 nm, and that of a toluene molecule is 0.67 nm, making adsorption separation a suitable method.