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Flow pattern identification for three‐phase distillation with a nonequilibrium modeling
Author(s) -
Chen Liang,
Repke JensUwe,
Wang Shuqing
Publication year - 2011
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.559
Subject(s) - distillation , non equilibrium thermodynamics , flow (mathematics) , mass transfer , discretization , phase (matter) , two phase flow , process (computing) , column (typography) , identification (biology) , computer science , mechanics , statistical physics , mathematics , thermodynamics , physics , chemistry , chromatography , mathematical analysis , ecology , telecommunications , quantum mechanics , frame (networking) , operating system , biology
The fear of the uncertain vapor–liquid–liquid hydrodynamics has guided process engineers away from a three‐phase involvement, of which the most uncertain is the flow pattern of the second liquid phase. Hence, a first‐principle model‐based estimation strategy was proposed to identify the flow pattern in the three‐phase distillation. Representative experiments were performed in a laboratory‐sclae packed column, and the results were sampled as reference data for the estimation. A dynamic nonequilibrium (NEQ) model was built up to consider the inter‐phase mass transfer rigorously. The resulting estimation problem was then discretized using the multiple‐shooting method, to formulate a large‐scale NLP problem with a finite number of decision variables. The estimated results reveal that the flow pattern of the second liquid has a close relationship with the liquid and gas loads, and it could play a critical role for the variation of the separation efficiency inside a three‐phase column. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.