A new approach to thermal integration of distillation sequences

This paper describes a new approach for synthesizing thermally integrated distillation sequences. There are two key developments in this research. First, the overall flowsheet is optimized simultaneously as opposed to the traditional technique of optimizing each tower sequentially followed by heat integration. Second, maximum energy recovery techniques are used to estimate the total energy requirements of the thermally integrated network, eliminating the need to synthesize a heat exchanger network on each function evaluation in the optimization routine. A frequently reported five component light alkane system (Rathore's Problem) was used to illustrate this approach. Optimized process flowsheets, energy savings and a comparison with literature values are presented.