A Method for Novel Multicomponent Distillation Sequences with Fewer Columns

A persisting challenge in multicomponent distillation has been to identify the optimal distillation sequence for a given application. Several researchers have provided solutions to the problem of synthesizing the complete search space of distillation configurations that use exactly n – 1 columns to separate a zeotropic feed mixture into n product streams. However, the search space of all feasible distillation configurations that use less than n – 1 distillation columns has not been completely explored. The Brugma and Kaibel configurations are probably the most well known among such fewer column configurations. These configurations use less distillation columns than the conventional ‘exactly’ n – 1 distillation column sequences while retaining the ability to make products with any pre-specified purity. We present a systematic procedure to synthesize the complete search space of configurations that use less than n – 1 distillation columns with emphasis on configurations that can make products of any pre-specified purity. Further, we have found an entire class of hitherto unknown fewer column configurations that also have the ability to produce all products of arbitrarily high purity. These novel configurations show great promise for reducing energy consumption and a systematic procedure to synthesize them will also be described.