SCI和EI收录∣中国化工学会会刊

›› 2011, Vol. 19 ›› Issue (6): 911-925.

• SEPARATION SCIENCE AND ENGINEERING • Previous Articles     Next Articles

Pinch Point Calculations and Its Implications on Robust Distillation Design

Daniel A. Beneke1,2, Seon B. Kim1, Andreas A. Linninger1   

  1. 1. Laboratory for Product and Process Design, Department of Chemical and Bio Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA;
    2. Centre of Materials and Process Synthesis (COMPS), School of Process and Materials Engineering, University of the Witwatersrand, Johannesburg, South Africa
  • Received:2010-05-25 Revised:2011-05-10 Online:2012-04-24 Published:2011-12-28

Pinch Point Calculations and Its Implications on Robust Distillation Design

Daniel A. Beneke1,2, Seon B. Kim1, Andreas A. Linninger1   

  1. 1. Laboratory for Product and Process Design, Department of Chemical and Bio Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA;
    2. Centre of Materials and Process Synthesis (COMPS), School of Process and Materials Engineering, University of the Witwatersrand, Johannesburg, South Africa
  • 通讯作者: Andreas A. Linninger, E-mail: linninge@uic.edu

Abstract: Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.

Key words: pinch point, column profile map, phase equilibrium model, temperature collocation

摘要: Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.

关键词: pinch point, column profile map, phase equilibrium model, temperature collocation