Adsorption Science & Technology (Nov 2007)

Single-Column Simulated Moving-Bed Process with Recycle Lag: Analysis and Applications

  • João M.M. Araújo,
  • Rui C.R. Rodrigues,
  • Ricardo J.S. Silva,
  • José P.B. Mota

DOI
https://doi.org/10.1260/026361707785082369
Journal volume & issue
Vol. 25

Abstract

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We report some conceptual and numerical results for a single-column chromatographic process analogous to a simulated moving bed (SMB) with asynchronous port switching. It is shown that the periodic state of the multi-column SMB unit is reproduced by a one-column chromatograph in which the part of its outlet stream that is not recovered as product is recycled back to the column with a lag of (N – 1)τ time units, where N and τ are, respectively, the number of columns and the switching interval of the equivalent SMB unit. This requirement holds true regardless of the port configuration or operational scheme of the analogous multi-column unit. The proposed one-column chromatographic process is a more compact, less expensive and simpler-to-operate alternative to the SMB. By changing the operation of the single-column chromatograph from the classical synchronous port switching to an optimized asynchronous Varicol mode, it is shown that one can easily compensate for a less perfect operation of the plug-flow device that implements the recycle lag.