A-priori Identification of Critical Points for the Design and Synthesis of Flexible Process Schemes

An approach for the a-priori identification of vertex and nonvertex critical points needed for the design and synthesis of flexible chemical plants is presented. The critical values of uncertain parameters are identified by maximizing design variables one-by-one, whilst simultaneously optimizing the economic objective function. In this procedure, the uncertain parameters are transformed into the continuous variables between prespecified lower and upper bounds. This task can be accomplished in two alternative ways: firstly, with an explicit derivation of Karush-Kuhn-Tucker (KKT) optimality conditions and secondly, with a two-level formulation. The values of the uncertain parameters obtained are then