A cyclic operating policy for batch distillation-theory and practice

This paper sets out a cyclic operation policy for batch distillation with r epeated filling and dumping of the reflux drum. The policy has several adva ntages compared to conventional schemes; it achieves the maximum attainable separation in the column; there is a minimal need for control and it is le ss sensitive to disturbances and therefore safer to operate. In this study, the optimal operation of the policy is considered for different column con figurations and it is found to have a considerable lower operating time tha n conventional policies for some separations. The practical implementation of the cyclic policy is discussed and results from a laboratory batch colum n with 8 sieve trays are presented. It is found that the cyclic policy is i ndeed easy to operate and yields satisfactory separation. (C) 1999 Elsevier Science Ltd. All rights reserved.