The issue of ethanol recovery in direct evaporation heat pump distillation for ethanol
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The last edit to this post was made by laziness on 2021-1-9 at 13:29. Hello, esteemed seniors. I have been working on heat pump distillation for ethanol and methanol recently, but I have a question: after the ethanol and methanol are heated by the compressor to supply heat to the reboiler, how can we ensure a stable extraction of the liquidified ethanol and methanol?
Is the bottom of the tower water? Is this compression ratio quite high? Are compressors for compressed ethanol/methanol a good choice? Regardless of the method used, the condensate should flow into the tank from the reboiler to control the liquid level inside the tank.
What is the purpose of this heater from S28 to S29? In principle, it isn’t necessary. The values for the circulation should be initialized based on the results obtained from a single tower. For this dual-circulation system, it’s advisable to determine first which one converges more easily (as far as I remember, the order of convergence for compression reboiling at the top of the tower and reduced-pressure condensation at the bottom is exactly the opposite, which helps with convergence). Additionally, practical feasibility must also be taken into account (mainly due to constraints related to the compressor seal and outlet temperature)
I have a question: by how much can the energy consumption be reduced using this method? What is the target moisture content for this tower?
Send me the CAD drawing and I’ll take a look for you. Email: bjzky@126.com
The bottom of the tower contains water; it is a two-stage compressor with a compression ratio of 3.6.
The heat exchangers in S28-S29 serve as auxiliary reboilers; when the heat source is insufficient, steam is used for supplementary heating to achieve the desired vaporization rate
What is saved is nothing other than the latent heat of the steam at the top of the tower. For example, if steam costs 200 yuan per ton and electricity costs 0.4 yuan per kilowatt-hour, costs can be reduced by approximately 65%.
The target alcohol content at the top of the tower is 95%, while the actual design value is 94% by mass
This post was last edited by goldliyang on 2021-2-1 at 15:33. Simulation and convergence are working fine; thank you for your patient assistance:handshake