How to separate an ethanol-benzene mixture?
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The boiling point of ethanol is 78.3°C, and that of benzene is 80.1°C. So how can a mixture of ethanol and benzene be separated?
Ethanol and benzene are immiscible, and separation by liquid-liquid extraction can be used.
Is ethanol insoluble in benzene? The statement on the second floor isn’t correct, is it? Water should be added to the system first, as water is miscible with ethanol while it is insoluble in benzene; thereafter, benzene and the ethanol-water solution can be separated by allowing them to settle and separate into layers. Water and ethanol can be processed using appropriate methods as required, such as distillation or rectification
Agree with the method suggested above; it’s simple and practical
The question posed by the original poster is quite interesting. Ethanol and benzene form an azeotrope; the composition of this azeotrope is 45% ethanol and 55% benzene on a molar basis, with an azeotopic temperature of 67.9 degrees. Therefore, it is not possible to separate them using distillation or conventional rectification methods. Methods such as extraction, extractive distillation, or azeotropic distillation can be employed. I’m sure there’s a good solution downstairs.
The method on the fourth floor is reasonable: first use water for extraction; after the two phases are separated, the benzene phase is subjected to azeotropic distillation to remove the ethanol-water-benzene azeotrope (64.85°C) and the ethanol-benzene azeotrope (68.24°C), leaving behind benzene； Ethanol-water-benzene is distilled off through aqueous-phase azeotropic distillation; water is removed from the bottom of the tower, and ethanol-water-benzene is then separated again to remove water. It’s quite complicated.
This post was last edited by minglan619 on 2009-9-25 at 17:23. It’s an experiment I conducted yesterday: given that the boiling points of ethanol and benzene are so similar, is it possible to separate them using distillation? If water is added, ethanol and water form an azeotrope; so how can ethanol be separated? 4# chinazhf
Back to floor 8: Indeed, after water extraction followed by distillation, an azeotrope is obtained that contains 95% ethanol.
I recommend using pressure swing distillation. I conducted experiments, and fractional distillation can separate ethanol from benzene, with recovery rates of 99% for both