Comparison of extractive distillation and pressure-swing distillation for acetone/chloroform separation

The separation of acetone from chloroform is difficult because the highly nonideal vapor–liquid equilibrium produces a maximum-boiling azeotrope. An earlier paper (Luyben, W. L. (2008). Control of the maximum-boiling acetone/chloroform azeotropic distillation system. Industrial & Engineering Chemistry Research, 47, 6140–6149) discussed the use of extractive distillation for making this separation. This paper studies the use of pressure-swing distillation for making the same separation.Results show that the extractive distillation process is much more attractive from the standpoint of both capital investment and energy consumption. But pressure-swing distillation avoids the potential problem of product contamination by the extractive solvent that must be added to the binary system.

► Economic comparison of pressure-swing and extractive distillation for the maximum-boiling acetone/chloroform azeotrope.
► Recycles between columns in pressure-swing distillation are the bottoms streams for maximum-boiling azeotropes and distillates for minimum-boiling azeotropes.
► Effect of the pressure sensitivity of the azeotrope found to be essentially the same in both cases.