Targeting the integration of multi-period utility systems for site scale process integration

A method to target the optimal integration of the utility system of a chemical production site for multi-period operation has been developed. This paper is organised in three parts. After introducing the problem to be solved, the first part reports about the mathematical model used to solve the integration problem when the production specifications of the processes in the industrial site are constant (here average production levels). In the second part of the paper, the multi-period utility requirements of the chemical processes are analysed. An optimisation problem is stated to compute the multi-period load scenario defining the utility requirements with a minimum number of operating periods sets to satisfactorily covering the yearly operation of the total site. A genetic algorithm is used to solve this problem. Furthermore, the generic mathematical formulation of the multi-period utility targeting is provided, including the possibility to deal with different sets of technologies for the synthesis of the utility system. The third part of this communication presents the results obtained for a realistic problem described in the introduction. Discussion of the limits and of the powerful features of the method developed is shortly presented.