Correlating experimental VLE data

[Uup115]

Hello,

the system is alcohol and water + pH-buffer that is supposed to alter the volatility of the mixture and I need to correlate the experimental data (x1,y1,T measured at constant P).

Question: Can I use binary models like margules, van Laar and NRTL to correlate the data and see if the models represent the experimental values correctly or do I need to treat this system as ternary?

If I need to treat it as ternary I don't know which model to use and how to use it because all the models I found are ment for a mixture of three liquids. I also found the eleyctrolyte-NRTL model but I am fairly certain that I will not find the literature parameter required for the pH-buffer that I am using.

any help would be appreciated
kind regards

 

[jbsteele]

Yes, you can use binary models like margules, van Laar, and NRTL to correlate the data. The binary models will assume that the system is made up of two components, alcohol and water, and that the pH-buffer does not significantly affect the volatility of the mixture. If you want to take into account the effect of the pH-buffer, you can use a ternary model such as UNIQUAC or a modified form of the electrolyte-NRTL model. The electrolyte-NRTL model requires literature parameters for the pH-buffer, so if you do not have access to those, you may need to find other ways to incorporate the pH-buffer into your model.