Multi-Stage Batch Distillation: Interactive Simulations
The first simulation will run on this page in your browser. The second simulation was prepared using Mathematica. Download the free Wolfram player, and then download the simulation CDF file (link given below or click on figure to download). Screencasts demonstrate how to use these simulations.
Multistage Batch Distillation
Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.
- For multi-stage batch distillation of a binary mixture without an azeotrope, what happens to the mole fraction of the distillate as the number of stages increases?
- For multi-stage batch distillation of a binary mixture without an azeotrope, what happens to the mole fraction of the distillate as the reflux ratio increases?
This simulation demonstrates how the reflux ratio, reboiler (still) composition, and number of equilibrium stages (all of which can be changed with sliders) affect the distillate composition (displayed above the graph) in a multi-stage batch-distillation (or continuous rectification) for a binary mixture. Each black dot on the y-x equilibrium curve denotes the composition at that equilibrium stage. Hover the mouse over a composition stage label (still, 1, 2, etc.) to display the composition at that stage. Select between a binary mixture with no azeotrope, a minimum-temperature azeotrope, or a maximum-temperature azeotrope. Stage 1 is defined as the first stage above the reboiler. This demonstration assumes constant molar overflow, 100% stage efficiency, and a complete condenser.
Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.
- For a minimum-boiling azeotrope at a mole fraction for component B of 0.60, as the number of stages increases, what happens to the mole fraction of the distillate?
- For a maximum-boiling azeotrope at a mole fraction for component B of 0.50, as the number of stages increases, what happens to the mole fraction of the distillate?
