Integrated production and utility system approach for optimizing industrial unit operations

To meet utility demands some industrial units use onsite utility system. Traditionally, the management of such type of industrial units is carried out in three sequential steps: scheduling of the manufacturing unit by minimizing inventory, estimating the utility needs of manufacturing unit and finally operation planning of the utility system. This article demonstrates the value of an integrated approach which couples the scheduling of manufacturing unit with operational planning of the utility system. A discrete-time mixed integer linear programming (MILP) model is developed to compare traditional and integrated approaches. Results indicate that the integrated approach leads to significant reduction in energy costs and at the same time decreases the emissions of harmful gases. (C) 2009 Elsevier Ltd. All rights reserved.