Study of a Batch Reactive Rectifier

Damköhler number

10

reflux ratio

10

number of stages

10

Consider an ideal ternary mixture subject to an equilibrium-limited chemical reaction

2B⇌A+C

. The relative volatilities and the chemical equilibrium constant are taken as

α

AC

=5

,

α

BC

=3

, and

K

eq

=5.5

. Pure

B

is fed to a reactive rectifier and it is assumed that the reaction takes place only in the still. This Demonstration plots the distillate composition versus time for user-set values of the Damköhler number

Da

, the reflux ratio, and the number of nonreactive stages in the rectifier. Compositions of components

A

,

B

, and

C

are plotted in red, green, and blue, respectively. It is clear from the snapshots that when

Da

is high, one gets pure

A

, pure

C

, and a minor intermediate fraction, which is rich in component

B

. Thus, it is possible to drive the reaction conversion to very high values to recover the pure products, components

A

and

C

.