Separation of the ethanol-water-propanol-butanol system
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Yesterday I encountered a problem regarding the separation of an ethanol-water-propanone-butanol system, with the following composition: water: 49.3%, ethanol: 41.3%, propanone: 3.3%, butanol: 6.1% (all as mass percentages). I conducted a simulation using a 3-column distillation setup: in the first column, high-purity propanol was obtained from the top, while ethanol-water-butanol mixture was obtained from the bottom; in the second column, the ethanol-water mixture was obtained from the top and high-purity butanol was obtained from the bottom; the third column was used to separate ethanol from water. Although the results met the separation requirements, I believe there are some areas that could be improved, such as the excessive number of plates in the first column (60 plates) and the high reflux ratio (30). In the second column, water formed azeotropes with both ethanol and butanol. Everyone can discuss and analyze whether there are any better solutions
It hasn’t been calculated yet; one could try using a complex tower, extracting the azeotrope of water and ethanol from the middle of the tower, with propylene coming out at the top and butanol at the bottom. Ethanol and water are fed into the tower to separate water from ethanol. It’s not clear whether separating the two towers is feasible.
The last edit to this post was made by bbslu on 2009-11-6 at 16:37; the reflux ratio should be around 30, otherwise the product will not be purified properly； There is an azeotrope formation in the two columns; at the top of the column, ethanol and water are separated, while at the bottom, it’s an azeotrope of water and butanol. A phase separator was added, but it keeps indicating that phase separation is not possible! Has LZ encountered this problem?
After separation in Column 1, the ethanol/butanol/water mixture at the bottom of the column contains about 90% water; how much energy would be required to vaporize all of this mixture to the top of the column?