General Formulation of the Optimization Problem

Emphasis is placed in this chapter on the usage of process simulators to carry out the optimization simultaneously with converging the recycle loops and/or decision variables. To do the optimization efficiently, simulators use one of three methods (1) successive linear programming (SLP), (2) successive quadratic programming (SQP), and (3) generalized reduced gradient (GRG). Emphasis in this chapter is placed on SQP, used by ASPEN PLUS and HYSYS.Plant. GRG, which is used by CHEMCAD, is not discussed here, but is covered by Edgar et al. (2001). 

Minimize (or maximize) / x, the objective function with respect to (w.r.t.) d, 

---