OPTIMAL SCHEDULING OF CYCLIC BATCH PROCESSES FOR HEAT INTEGRATION .1. BASIC FORMULATION

Significant savings in the utility cost of batch plants can be obtained by heat integration coupled with the rescheduling of operation times. In this work, efficient scheduling models are developed for maximization of heat recovery for the case of no intermediate storage with holding time (NIS) in cyclically operated single-product campaigns. In this development, the product recipe network is assumed to take the form of an arborescence and each unit is assumed to be assigned to a single task. A mixed integer linear programming (MILP) formulation is proposed to determine the operating schedule for maximum heat integration between the batch streams to reduce the utility consumption. Solution of this formulation can be readily obtained with a commercial MILP solver. Numerical examples are presented to illustrate the scope of the problems which can be handled with the formulation.