In my model I get the following error: System.Exception: NIST-MODFAC Error: Could not find interaction parameter for groups CH3OH / AC2O. Activity coefficient calculation will give you inconsistent results for this system. I want to ignore the missing parameters for simplicity reasons, and I'm not sure where I can disable this warning. Where in DWSIM can I do that? I only see an option for ignoring missing UNIQUAC/NRTL parameters
In my model I get the following error: System.Exception: NIST-MODFAC Error: Could not find interaction parameter for groups CH3OH / AC2O. Activity coefficient calculation will give you inconsistent results for this system. I want to ignore the missing parameters for simplicity reasons, and I'm not sure where I can disable this warning. Where in DWSIM can I do that? I only see an option for ignoring missing UNIQUAC/NRTL parameters
In my model I get the following error: System.Exception: NIST-MODFAC Error: Could not find interaction parameter for groups CH3OH / AC2O. Activity coefficient calculation will give you inconsistent results for this system. I want to ignore the missing parameters for simplicity reasons, and I'm not sure where I can disable this warning. Where in DWSIM can I do that? I only see an option for ignoring missing UNIQUAC/NRTL parameters
Hi Daniel, Thank you for your quick help. I tried regressing my experimental data using UNIQUAC. I attached the paper I got the VLE data from, for furfuryl alcohol and furfural. But I get a regression error that I don't understand. Could you take a look at this file and see what's generating the error? Thank you for all your help
For modeling purposes using the free software, would you suggest just ignoring the missing interaction parameters?
I found experimental VLE data that I can input for doing a Txy data regression for estimating the interaction parameters between furfuryl alcohol and furfural. When I tried using MODFACT-NIST to give an initial estimation, I get the following error "Could not find interaction parameter for groups CH3OH/AC2O. My confusion is that I didn't use either of those MODFAC groups to build my furfuryl alcohol compound. I wonder if this is why I couldn't get an initial estimation for the parameters on the Configure...
I built two compounds using MODFAC-Nist and Joback groups, and I hand calculated their UNIQUAC R and Q parameters. I'm trying to estimate the UNIQUAC interaction parameters between several compounds, including my built ones, in the Configure Property Package window. However, when I estimate the interaction parameters using the "Estimate MODFACT Nist" function, all interaction parameters involving my built compounds return a 0 value while compounds already in the DWSIM database have non-zero interaction...
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
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?
Thank you, very helpful!
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?
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...
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...
Sorry, had a typo in my original question. I meant I have literature resources that helped me estimate those parameter values. Would like to know how I can input those parameter values in DWSIM
Hi Daniel, I'm working on a simulation where I'd like to use the Modified UNIFAC (Nist) property package. The compounds in my system contain Furan and OH groups, and it seems that the interaction parameters between those groups are missing. I have some literature resources that I have used to estimate the properties. Is there a way I can manually input those values in DWSIM?