Consider a ternary mixture of components
with relative volatilities
. The mixture is subject to an equilibrium-limited chemical reaction
with reaction rate
, where the equilibrium constant,
. The mixture is fed to a reactive distillation column with 13 plates; the feed stage location is stage 5, the reactive stages run from 2 to 7, and the feed composition contains 100% mole
. The feed flow rate is chosen as 100 kmol/hr. For simplicity, we assume constant molal overflow (CMO) and neglect heat effects.
This Demonstration shows two profiles: (1) the composition versus plate number for components
(in red, blue, and green, respectively) with the reactive zone shown in light blue and (2) a ternary diagram with the composition of
versus the composition of
in mole %. In the second profile, the feed composition is shown by a purple dot and reactive stages 2 to 7 are displayed in blue.
The Damköhler number,
, is set to 200. The reboil ratio is chosen so that distillate and bottom flow rates are equal (i.e.,
is the reboil ratio and
is the reflux ratio). For this very large Damköhler number, the simulation represents a situation close to reaction equilibrium (i.e.,
This reaction mechanism corresponds to the case of a metathesis or disproportionation of olefins (for example cis2-pentene ⇌ cis2-butene + cis2-hexene).