Abstract
A new, efficient model reduction method for multistage distillation columns is proposed by combining the orthogonal collocation method and the two-part modular concept. To assess the performance of the proposed method, numerical simulation was performed for two distillation examples—the high-purity freon 11–12 binary system and the nonideal ethanol–1-propanol–water ternary system— and the results were compared with those obtained by the methods of existing collocation as well as rigorous equation solving.
It was shown that the proposed method reduces the computing time by about 40% with accuracy comparable to that of the rigorous methods. Furthermore, while the existing collocation method could not properly reproduce the sharp changes of variables in the vicinity of the feed stage, the proposed method could successfully reproduce them as well.
