Separation of methanol from water
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Question: How many theoretical plates are required to separate methanol from water (with a required methanol purity of 99.8%)?
To separate methanol from water, a single tower is not sufficient to meet your requirements, as methanol and water have an azeotrope. To meet your separation requirements, special column separation is required. For your reference.
Agree with what was said above; the three-column distillation process is quite popular these days. It’s possible to obtain methanol of grade A (with an ethanol content of less than 100 ppm), and the pressure plate should have a value greater than 40
A single tower can meet the requirements; its height is approximately 15 meters. Our company uses methanol produced by single-tower distillation to manufacture sodium methoxide
It’s over 40 units, depending on the tower type you choose
Nonsense. Where did I see that methanol and water have an azeotrope?
Ethanol and water can form an azeotrope; it’s not methanol, so don’t get them mixed up
Methanol and water have an azeotrope, at around 60 degrees or so~~ Extraction distillation or vacuum distillation is recommended~~ The azeotrope occurs due to the formation of a conjugate solution~~ This phenomenon is present in many solutions~~ Last edited by cnjae on 2008-1-21 17:23]
This question is very simple; you can find the answer by looking up information. Understanding the process of methanol production will help clarify things further. Methanol and water do not exhibit an azeotrope at normal pressure, under reduced pressure, or at pressures that are not too high (it’s not known whether such an azeotrope exists at pressures in the tens range). 1. Methanol and water are completely miscible; it’s highly inappropriate to use a cap for a conjugate solution. 2. Early methanol plants generally used a two-column process (a pre-column and a main column); the pre-column was used to remove light components, while the main column was responsible for the separation of methanol from water. With this setup, it was possible to obtain methanol with a water content of less than 0.1%. If you were to suggest methods such as extractive distillation or vacuum distillation to break the azeotrope, it would probably make them laugh out loud. 3. The two-column process also involves extractive distillation; this technique involves adding water as an extractant at the top of the pre-column or even in the reflux tank in order to improve the separation of propylene and other light components from methanol (propylene forms an azeotrope with methanol). 4. Modern methanol production generally employs a three-column process (pre-column, atmospheric column, and pressurized column), where the atmospheric column and the pressurized column work together in a double-effect distillation system to save energy; this has nothing to do with azeotropy. Some units have an additional recovery tower, whose purpose is to recover methanol from fusel oils, and it is not used for breaking azeotropes.
If a lower water content in methanol is required, a molecular sieve adsorption tower can be considered, using 3A molecular sieves to absorb the water present. 99.95% will also work.
We use packed towers here; basically, 40 theoretical plates are achieved using the structured packing from Tianjin Beiyang