Regarding alcohol distillation
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For atmospheric distillation, what is the theoretical number of theoretical plates required to distill 50% aqueous ethanol to 93% purity?
This post was last edited by *nht1 on 2017-6-24 21:18. The theoretical number of plates alone is not sufficient; the feed rate and withdrawal rate also need to be taken into account. Moreover, tower distillation is no longer needed; there are new devices, such as supergravity separation technology.
New devices and technologies are still in the conceptual stage; it will take some time before they can completely replace existing ones – at least a decade or so, and possibly up to 50 years. Has paperless office work replaced pencils and writing brushes? Have LED lights replaced candles?
For this, use the operating line equation derived from the process calculations to perform a step-by-step calculation to determine the theoretical number of theoretical plates.
Both mass percentage and molar percentage are ratios, and their values are the same.
Can a 50 wt % ethanol aqueous solution and a 50 mol % ethanol aqueous solution have the same concentration? The product also has this problem. If the product is 93 wt% ethanol, this can be achieved through ordinary distillation; however, if it is 93 mol% ethanol, ordinary distillation is not sufficient.
The required purity is related to the number of tray levels. As for the so-called production rate, it is related to the tower diameter and the structure of the trays – that is, the so-called space velocity
I see, thanks for letting me know
What is mentioned here is on a volume percentage basis; the raw alcohol accounts for 50% by volume, which corresponds to approximately 42% by mass； Distilled final alcohol: 93% by volume, which is approximately 90% by mass. Thank you for your diligence!
It can be achieved using both distillation and rotating beds.