Distillation-Column Product Purity as Function of Feed Thermal Quality
Consider an ideal equimolar binary mixture of benzene and toluene at . This mixture is fed to a 10-stage column with a total condenser and partial reboiler. The feed stage is stage 7. Column stages are counted from the top. The feed flow rate is taken equal to . You can set the values of the feed's thermal quality , the reflux ratio , and the reboil ratio .
The Demonstration plots the top (in dashed blue) and bottom (in dashed red) product purities versus the thermal quality of two-phase feed mixtures () as well as superheated feed mixtures (). It is possible to extend the code to include subcooled () feed mixtures. The code uses a rigorous approach, which takes into account both energy and mass balances. The computation is based on the arc length continuation technique.
In addition, the Demonstration computes the liquid-phase composition profiles. The blue and red points correspond to benzene and toluene, respectively. All results found in this Demonstration show excellent agreement with those given by HYSYS (http://www.aspentech.com/hysys). Indeed, the distillation column temperature profile is compared, for , , and , between this calculation (the open blue circles) and HYSYS result (the filled red dots).