(337d) Fully Automatic Computer-Aided Design and Synthesis of Complex Separation Networks

We propose a novel computer-aided design for complex heat-integrated column networks to identify optimal energy efficient configurations. Since various complex column configurations including Petlyuk, Kaibel, divided wall columns, side-stripper and rectifiers have better energy efficiency than simple separation networks, we target to design complex column networks to separate multicomponent mixtures. However, complex column network synthesis is a challenging problem because the rigorous mass, equilibrium, summation and heat (MESH) equations lead to non-smooth fragmented search spaces. Moreover, combinatorial complexity grows rapidly with the number of components to be separated. Our new computer-aided design methodology deploys an inverse design methods based on temperature collocation which substantially reduces the problem dimension. We will demonstrate new algorithmic approaches like the bubble point distance using polynomial algebra, as well as and a hybrid niche algorithm for the global search for feasible, effective and optimal energy efficient designs. This methodology allows for design and synthesis of the complex column network in a fully automatic fashion. The solutions obtained by our synthesis method agree closely with rigorous mass, equilibrium, summation and heat (MESH) computations verified with the commercial flowsheet simulator AspenPlus. Thus, our design method is essentially equivalent to rigorous flowsheet synthesis. In conclusion, the rigorous solutions to separation problems can be obtained in a fraction of valuable engineering design time by proposed algorithms. Furthermore, the automatic and rigorous flowsheet synthesis is apt to systematically address industrial-size process design problems such as the synthesis of energy-efficient separation networks, layout of biorefineries with novel feedstocks or sustainable process for reduction of greenhouse gases emissions.