Page 225 - Elements of Chemical Reaction Engineering 3rd Edition

Sec. 4.7 Unsteady-State Operation of Reactors 197

(4-68)
1.0,

(4-69)

(4-70)

4.7.3 Reactive Distillation

The distillation of chemically reacting mixtures has become increasingly
common in chemical industries? Carrying out these two operations, reaction
and distillation, simultaneously in a single unit results in significantly lower
capital and operating costs. Reactive distillation is particularly attractive when
one of the reaction products has a lower boiling point, resulting in its volatil-
ization from the reacting liquid mixture. An example of reactive distillation is
the production of methyl acetate:

CH,COOH + CH,OH & CH,COOCH, + H,O
k2
By continually removing the volatile reaction product, methyl acetate, from the
reacting liquid-phase reaction, the reverse reaction is negligible and the reac-
tion continues to proceed towards completion in the forward direction.
Although reactive distillation will not be treated in detail, it is worthwhile
to set down the governing equations. We consider the elementary reaction
A+B e
GI-D
in whiclh A and €3 are charged in equal molar amounts and species D is conitin-
uously boiled off, A balance on species A gives

(4-7 1 )

H. Sawistowski and P. A. Pilavakis, Chem. Eng. Sci., 43, 355 (1988).