REDESIGN OF A MULTIPURPOSE BATCH PILOT-PLANT WITH CLEANING IN-PLACE (CIP) INTEGRATION

The retrofit design of a multipurpose batch pilot plant is studied so as to accommodate the addition of a new product. A model is utilised w hich represents in detail structural and operational characteristics a s required for production scheduling, while also accounting for cleani ng in place (CIP) integration. The State Task Network concepts for def ining process recipes and procedures are augmented by the definition o f the equipment states (unit dirty, connection dean, etc.). A superstr ucture of several proposed plant modifications is considered to debott leneck the plant and provide increased flexibility, including piping r econfigurations and the replacement of the existing flow plates with d ouble seat valves manifolds. The retrofit problem is formulated as a M ixed Integer Linear Program (MILP) and solved using a branch and bound technique. The best compromise between extra capital cost (plant reco nfiguration) and operating cost/revenues (operating schedule and produ ction amount of the new product) is obtained by maximising the annuali sed profit. Results show that a small capital expenditure permits the production of the new product within the original time horizon.