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DanWBR / dwsim

DWSIM is a Steady-State and Dynamic Sequential Modular Chemical Process Simulator for Windows, Linux and macOS.
https://dwsim.org
GNU General Public License v3.0
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UNIFAC-LL #118

Closed eliasjr70 closed 3 years ago

eliasjr70 commented 3 years ago

Dear Daniel, I have been trying for some time to use the UNIFAC model with parameters for liquid-liquid equilibrium (UNIFAC-LL) but I always get a error "parameter not found". The curious thing is that this occurs for subgroups within the same main group ... A short video of the error is attached. Using another UNIFAC, either original one or UNIFAC-NIST, there is no problem. A file with the simulation prepared in the video is also attached. If I can provide any more useful information, please let me know. Regards, Elias. teste_LL.zip https://user-images.githubusercontent.com/79600458/109049018-87d5e700-76b6-11eb-8643-41f1c921d944.mp4 https://youtu.be/xjszz6RgF-o

DanWBR commented 3 years ago

@eliasjr70, this is because UNIFAC-LL doesn't have many parameters. You can use one of the Modified UNIFAC methods as their parameters were regressed from LLE data too, so it is safe to use.

eliasjr70 commented 3 years ago

Thanks for the quick answer!. But shouldn't we expect any interaction between CH / CH2 groups and other ordinary groups such as H2O and OH? Moreover, they seem to be present: image These are the parameters of MAGNUSSEN et al. (1981), right? Regards!

DanWBR commented 3 years ago

@eliasjr70 that's a hard question. This is one of the oldest property packages in DWSIM, I remember reading the original paper, I probably have it here in one of my backups.

eliasjr70 commented 3 years ago

No worry about the reference, @DanWBR. My concern is about the proper functioning of the package. I tried to illustrate the use of different models in LLE calculations to my Thermodynamics students, then I got the error. Then I tried to edit the parameter table to fill up the missing ones, but they're already there as you can see in my previous message.

DanWBR commented 3 years ago

I've fixed the error but it seems that UNIFAC-LL is not suitable for anything other than LLE, that is, it won't generate a nice-looking VLE binary diagram...

eliasjr70 commented 3 years ago

Dear @DanWBR, thank you for the help! My interest now is LLE, so it will be very useful. Hope I can keep helping to find bugs. My best regards, Elias.

eliasjr70 commented 3 years ago

Dear @DanWBR, I have recently donwnloaded the 6.4.5 version and it's working just fine. Thank you!