I am currently doing a design project and would wish to design an extractive distillation column to separate o-xylene from xylene isomers.
I've met a difficulty when designing this column. I am using Aspen HYSYS for my design at the moment and have chosen UNIQUAC as my fluid package. However, it does not change the relative volatility of m-xylene to o-xylene as suggested by a patent when the solvent is added. I do not have the experimental interaction parameters. I have used different solvents for this case and none of them was able to have any effects on the relative volatilities of the xylene isomers.
Is there any way around this problem? Your help is very much appreciated.