Simultaneous Design of Heat Integrated and Thermally Coupled Distillation Systems

Abstract In this work we present a methodology for synthesizing sequences of columns that combine both, the heat integrated and the thermally coupled distillation columns. As a consequence it is possible to design systems capturing simultaneously the advantages of these two approaches. A superstructure based on separation tasks rather in actual columns is proposed. This approach is more flexible that assuming a rigid sequence of columns. Logical relationships are introduced to assure feasibility configurations and that the pressure levels are compatible: the flow transfer between columns that form the basis of thermally coupled system are made basically at the same pressure, but in a given sequence different pressure levels are possible in order to allow the heat exchange if necessary. The problem is formulated as a Generalized Disjunctive Programming problem and solved as an MINLP.