1 LP-Based Heuristic Procedure for the Optimal Design of Water Using Networks with Multi-contaminants

This paper proposes a new strategy for the optimal design of water-using networks in industrial systems featuring possibly more than a single water source and multiple contaminants. The model formulation is supported on a superstructure that exploits reuse opportunities and gives rise to a non-convex nonlinear problem which often leads to local optimal solutions. To overcome this, the new approach generates multiple initialization points, one for each possible sequence of operations, where a particular starting point is obtained by the sequential solution of a small set of related linear programs. The best solution of the several nonlinear problems that are solved is then assumed to be the global optimal solution. The results obtained for a set of case studies have shown that the best initialization point is often the global optimal solution and that the procedure as a whole is efficient in escaping local optima. 1