Counterflow vapour-liquid exchange processes using ammonia/water.

Author(s) : HEROLD K. E., PANDE M.


Rectification and inverse rectification are processes that are routinely modelled for absorption cycle analysis. The simplest models that provide reasonable results model the transfer processes as reversible which implies that vapour-liquid equilibrium exists everywhere in the column, but these models also imply that the columns have heat transfer along their length which is difficult to effectively achieve in practice. The simplest type of column to design has an adiabatic shell. The analysis of an adiabatic column is usually done using a Ponchon diagram and invoking the concept of a theoretical plate. This analysis is quite useful in that it accounts for the irreversibilities inherent in the adiabatic design. As a result, it predicts somewhat lower performance than that obtained from the reversible model. The theoretical plate model is based on a plate type column and is not particularly applicable to a packed column design. Thus, another type of design model is needed which accounts for the various transfer processes more directly instead of only accounting for the thermodynamics details. A packed column design model is proposed, demonstrated and compared with the simpler models to clarify the relationship amongst the models.


  • Original title: Counterflow vapour-liquid exchange processes using ammonia/water.
  • Record ID : 1998-0238
  • Languages: English
  • Source: Ab-sorption 96. Towards sustainable technologies. Proceedings./ Ab-sorption 96. Vers les technologies durables. Comptes rendus.
  • Publication date: 1996/09/17
  • Document available for consultation in the library of the IIR headquarters only.


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