Batch distillation in a column with a middle vessel can avoid many of the disadvantages associated with the regular batch distillation processes. In this paper, we present an experimental investigation of the separation of a zeotropic ternary mixture via total reflux operation and of the separation of an azeotropic binary mixture via batch-wise extractive distillation. Moreover, the results obtained for the two processes are compared with the experimental results of the corresponding regular batch distillation processes carried out in the same pilot plant. (C) 2003 Elsevier B.V. All rights reserved.