[Help] Distillation column design
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I need to complete the course project and have run into some problems. I’m asking for help from everyone. 1. The task assigned by the teacher was to separate dimethyl carbonate from methanol, but the operating pressure at the tower top was given. A phase diagram for the corresponding pressure cannot be found. Instead, a phase diagram with higher pressure and more satisfactory conditions was found. May I use it? If that’s not possible, then without knowing the phase diagram or the activity coefficients, it’s impossible to design a distillation column. Please help, thank you
It seems that some people have published thermodynamic data. Look for papers by Wang Feng, Sun Yuhan, and others from the Coal Chemistry Institute to see if there are any data on stress that you need. If that doesn’t work, a slight extrapolation will be necessary.
Go and learn about ASPEN; distillation is relatively simple, and two-stage or three-stage series distillation should be manageable
Firstly, it is impossible to obtain methanol through pressure-driven distillation from the tower top; the boiling point of methanol is 64.7°C, while that of the azeotrope is 62.7°C, and the material circulating at the tower top is the azeotrope. If a methanol content of ≥99.5% is to be obtained at the top of the tower, extraction distillation is the only option. So it is impossible to achieve the desired result: with a pressure of 1 MPaG at the top of the tower, the DMC alcohol concentration can only be reduced to 5-6%, and such a high methanol content cannot be obtained.