A systematic procedure for retrofitting chemical plants to operate utilizing different reaction paths

A systematic procedure has been developed and a software code created to examine continuous petrochemical plant retrofit problems. The procedure is hierarchical, and it provides stopping points so that little work needs to be done to reject a poor project. It is structured in a way that first sets minimum targets for the retrofit project, and it uses an efficient flow sheet structure filter to look at only the subset of possible flow sheet structures that have the potential for being profitable. The procedure then uncouples the flow sheet evaluation problem into two parts. First, the flow sheet is examined by neglecting the energy integration network. Second, the best flow sheet found without considering the heat-exchanger network is then examined by using existing energy integration procedures and considering the existing heat-exchanger area