I want to build out a compound in DWSIM, and I know I want to apply the Modified UNIFAC (NIST) method as a first attempt for modeling my process. I noticed that there are some subgroups available in UNIFAC and not in MODFAC and vice versa. For building out my compound, I'm confused as to whether I should build out my compound using both UNIFAC and MODFAC available subgroups. So more specifically, if I know I want to apply the Modified UNIFAC (NIST) method, should I build out my compound using only MODFAC groups? Or should I build out the compound using both UNIFAC and MODFAC groups? Would UNIFAC (not MODFAC) groups have an impact on the Modified UNIFAC (NIST) property method? Thank you for your help
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Sorry I have an additional question. I'm trying to build out furfuryl alcohol in the compound creator. I specified my NIST-MODFAC groups, and I added some of the constant properties I found online for the molecule. I also calculated the R and Q UNIQUAC parameters from available tabulated data. For the constant property values I didn't have information for, I checked the Joback calculation box. When I exported the compound as a JSON file, the properties I wanted to do the Joback calculation just returned as 0. I've attached the file if you have time to look at it, but I'm not sure how to fix this issue.
Did you try getting data from online sources? It seems that your compound is a "known" one, so there must be data on the internet that DWSIM can retrieve.
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I had tried importing data from the Chemeo database but when I entered the CAS number, nothing was popping up in the dialog. Eventually I want to build a custom molecule, and so I wanted to try incorporating the Joback calculations since I won't have information such as critical temperature, etc. In general, how would I get DWSIM to perform the Joback calculations? Do I need to specify more than just my MODFAC groups?
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I modified your definition:
* remove all UNIFAC groups - you can't use this model as the group for oxygen in ring is missing here.
* From UNIFAC groups the Joback groups are automatically defined. This is not possible from MODFAC and has to be done manually therefore.
* I added the correct groups inbothe MODFAC models
* I assigned the required Joback groups -> now you can try to calculate parameters automatically. Molecular weight is calculated automatically from Joback groups now.
Quick question, in my model I imported my original Furfuryl Alcohol compound into the database. I want to replace that compound in the database with this new file. Is there a way I can "remove" my original user created Furfuryl Alcohol compound in the database so I don't confuse it with this new file?
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A follow up to my original question, I tried importing my revised Furfuryl Alcohol.json file to replace the previously uploaded Furfuryl Alcohol compound, but I received the error message "the given key was not present in the dictionary." I'm not sure how to resolve this issue
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Hi Daniel,
I want to build out a compound in DWSIM, and I know I want to apply the Modified UNIFAC (NIST) method as a first attempt for modeling my process. I noticed that there are some subgroups available in UNIFAC and not in MODFAC and vice versa. For building out my compound, I'm confused as to whether I should build out my compound using both UNIFAC and MODFAC available subgroups. So more specifically, if I know I want to apply the Modified UNIFAC (NIST) method, should I build out my compound using only MODFAC groups? Or should I build out the compound using both UNIFAC and MODFAC groups? Would UNIFAC (not MODFAC) groups have an impact on the Modified UNIFAC (NIST) property method? Thank you for your help
Hi,
UNIFAC and MODFAC are different models, so you'll need to define the structure on both if you want to use both.
Hi Daniel,
Sorry I have an additional question. I'm trying to build out furfuryl alcohol in the compound creator. I specified my NIST-MODFAC groups, and I added some of the constant properties I found online for the molecule. I also calculated the R and Q UNIQUAC parameters from available tabulated data. For the constant property values I didn't have information for, I checked the Joback calculation box. When I exported the compound as a JSON file, the properties I wanted to do the Joback calculation just returned as 0. I've attached the file if you have time to look at it, but I'm not sure how to fix this issue.
Did you try getting data from online sources? It seems that your compound is a "known" one, so there must be data on the internet that DWSIM can retrieve.
Check this
I had tried importing data from the Chemeo database but when I entered the CAS number, nothing was popping up in the dialog. Eventually I want to build a custom molecule, and so I wanted to try incorporating the Joback calculations since I won't have information such as critical temperature, etc. In general, how would I get DWSIM to perform the Joback calculations? Do I need to specify more than just my MODFAC groups?
I modified your definition: * remove all UNIFAC groups - you can't use this model as the group for oxygen in ring is missing here. * From UNIFAC groups the Joback groups are automatically defined. This is not possible from MODFAC and has to be done manually therefore. * I added the correct groups inbothe MODFAC models * I assigned the required Joback groups -> now you can try to calculate parameters automatically. Molecular weight is calculated automatically from Joback groups now.
I hope this helps.
Thank you, very helpful!
Quick question, in my model I imported my original Furfuryl Alcohol compound into the database. I want to replace that compound in the database with this new file. Is there a way I can "remove" my original user created Furfuryl Alcohol compound in the database so I don't confuse it with this new file?
A follow up to my original question, I tried importing my revised Furfuryl Alcohol.json file to replace the previously uploaded Furfuryl Alcohol compound, but I received the error message "the given key was not present in the dictionary." I'm not sure how to resolve this issue