SUPERTARGETING: Different Process Structures for Different Economics

Abstract

Pinch technology has recently introduced techniques for optimizing integrated energy systems before design. The procedures apply to heat exchanger networks, heat pumps, combined heat and power schemes, and utility systems. They allow overall energy and capital cost targets to be compared and varied ahead of design to seek the optimum cost tradeoff. Near global optimality of the final design is virtually guaranteed, even for complex and highly constrained industrial problems. A key concept is that of supertargeting. This paper describes a case study application involving supertargeting and compares the approach to conventional techniques for optimal design. The example used is the heat exchanger network for a chemical solvents process. To demonstrate the approach fully, the design is carried out more than once. The prevailing economic conditions are varied to examine their influence on design. It is shown how fundamentally different network structures are optimal under different economic situations. Finally, topology traps are identified which prevent such different solutions evolving from each other through conventional design techniques.