Consider a ternary mixture of components
with relative volatilities
. This mixture is subject to an equilibrium-limited chemical reaction
with reaction rate
, where the equilibrium constant
. This mixture is fed to a reactive distillation column such that the total number of plates is equal to 14, the feed stage location is stage number 5, the reactive stages are from stage 2 to stage 7, and the feed composition is equimolar in
(i.e., the feed is composed of 40% mole
, 40% mole
, and 20% mole
). The feed flow rate is chosen equal to 100 kmol/hr. For simplicity, the constant molal overflow (CMO) assumption is made and heat effects are neglected.
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 where the composition of
versus the composition of
is in % mole. In the second profile, the feed composition is shown by a magenta dot and the reactive stages (stages 2 to 7) are displayed in blue.
You can set the values of the Damköhler number,
, the reflux ratio, and the reboil ratio. When
, one recovers the case where no reaction is taking place. If
is very large, the simulation represents a situation close to reaction equilibrium (i.e.,
One snapshot shows a case where the reflux ratio is very high, a situation close to the total reflux operation. For such a situation, the bottom is almost pure
and the distillate contain very little
. The distillation flow is very small and the distillate stream can be recycled if desired. Thus, for this specific operation, one can produce
is the desired reaction product, and convert both reactants
with a single piece of equipment.