The interactions of design and control; double-effect distillation

A general, rigorous dynamic model is described for studying the interaction s of design and control in a double-effect distillation system. Two approac hes are adopted. In the first, the steady-state process design and the cont rol system are optimized sequentially; potential operability bottlenecks ar e identified and the economic advantage of double-effect systems over conve ntional single column systems is demonstrated. In the second approach, the process design and the control system are optimized simultaneously leading to a more economically beneficial system than that obtained using the seque ntial approach. (C) 2000 IFAC. Published by Elsevier Science Ltd. All right s reserved.