Distillation Column Calculation Incorporating Pressure Drop Effect

Consider a distillation column separating a quaternary mixture of benzene, toluene, -xylene, and ethylbenzene. This column has 10 stages, a total condenser, and a partial reboiler. The feed stage location is stage five counting from the top. The feed composition is 25 mole % for each of the four components. The feed quality is taken to be 1. The feed flow rate is set to 10 kmol/hr. The reboil and reflux ratios are both chosen to be 5.
This Demonstration uses a rigorous approach (solving MESH equations) and takes into account pressure drop effects in both the condenser and the reboiler as well as in the trays. You can vary these various pressure drops. The pressure at the bottom of the column is set to 151.325 kPa. The Demonstration displays the composition versus the stage for all four components (benzene in orange, toluene in blue, -xylene in green, and ethylbenzene in red), the temperature profile inside the column, as well as the vapor and liquid flow rates (magenta and blue, respectively). The results obtained are compared with Aspen HYSYS for two cases (see last two snapshots with two different sets of reboiler, condenser, and trays pressure drops).


  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
  • [Snapshot]
  • [Snapshot]


Expressions for pure component vapor and liquid enthalpies were adapted from Aspen HYSYS.
The mixture is assumed to obey Raoult's law since it is composed of four aromatic compounds at a moderate pressure.
[1] E. J. Henley and J. D. Seader, Equilibrium-Stage Separation Operations in Chemical Engineering, New York: Wiley, 1981.
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.

Mathematica »
The #1 tool for creating Demonstrations
and anything technical.
Wolfram|Alpha »
Explore anything with the first
computational knowledge engine.
MathWorld »
The web's most extensive
mathematics resource.
Course Assistant Apps »
An app for every course—
right in the palm of your hand.
Wolfram Blog »
Read our views on math,
science, and technology.
Computable Document Format »
The format that makes Demonstrations
(and any information) easy to share and
interact with.
STEM Initiative »
Programs & resources for
educators, schools & students.
Computerbasedmath.org »
Join the initiative for modernizing
math education.
Step-by-Step Solutions »
Walk through homework problems one step at a time, with hints to help along the way.
Wolfram Problem Generator »
Unlimited random practice problems and answers with built-in step-by-step solutions. Practice online or make a printable study sheet.
Wolfram Language »
Knowledge-based programming for everyone.
Powered by Wolfram Mathematica © 2018 Wolfram Demonstrations Project & Contributors  |  Terms of Use  |  Privacy Policy  |  RSS Give us your feedback
Note: To run this Demonstration you need Mathematica 7+ or the free Mathematica Player 7EX
Download or upgrade to Mathematica Player 7EX
I already have Mathematica Player or Mathematica 7+