Computer-aided total flowsheet synthesis

Building on a previous approach, a systematic computer-based method for synthesizing a total flowsheet has been developed. This work uses a hierarchical concept, whereby separation tasks selected by the algorithm at the top level are converted to cost-estimated sharp separation sequences at the second level. The strategy at both levels is heuristic and evolutionary. Only the top-level system is described here, although the results include both phases. The synthesis of separation tasks is described by Lu and Motard, and extends the work of Nath and Motard.The flow rates and sizes of processing tasks are determined by a new goal-lumping strategy and a successive linear programming algorithm. Information from the lower level design of separations is fed back to the top-level decision procedure. The entire system is self-adaptive, but also includes opportunities for interaction by the user. Several test problems indicate that the present approach is superior to earlier work.