Divided wall distillation column: rationalization of degree of freedom analysis



The present work attempts to rationalize the degrees of freedom analysis of a divided wall distillation column for steady-state simulation using detailed mathematical model, which contains the MESHD equations (conventional MESH equation plus the pressure drop equation). In a divided wall distillation column, pressure difference plays an important role in deciding vapour and liquid flow rates across trays in the divided section. It is observed that for a given divided wall distillation column or Petlyuk column operating under steady state conditions with known feed and condenser pressure, the degrees of freedom is four. This is one higher than that for a conventional distillation column with three product streams (distillate, bottoms and the intermediate product). If this extra degrees of freedom is used to specify liquid split, then no extra degrees of freedom is left to specify vapour split ratio.


Tray Stage Number CTHEORETICAL Foundation Main Column Condenser Pressure 
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© Pleiades Publishing, Ltd. 2012

Authors and Affiliations

  1. 1.Department of Chemical EngineeringThapar UniversityPatialaIndia
  2. 2.Department of Chemical EngineeringIndian Institute of TechnologyRoorkeeIndia

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