Hi,
I am using the CADET Process and have observed that the concentrations of raffinate and extract are always lower than the feed concentrations. My literature review revealed that SMB (Simulated Moving Bed) can operate in two modes: as a fractional separator, which separates components, and as a concentrator, which enriches the concentration of components, particularly the extract.
According to the Equilibrium Theory for linear adsorption isotherm, Lee and Wankat (2011) stated, “For isothermal and isocratic operation of an SMB process, the adsorption curve of a single solute is identical in every zone, so that it is impossible to obtain a higher concentration product than the zone equilibrium concentration, which is lower than or equal to the feed concentration.” Similarly, Zhong and Guiochon (1996) mentioned that as long as the safety margin is greater than or equal to 1 (β ≥ 1), the raffinate and extract concentrations will never exceed those in the feed.
Given these findings, I would like to understand how an SMB can be used as a concentrator. Additionally, I am interested in knowing whether the Equilibrium Theory can be applied to a concentrator SMB and how, and if not, what the reasons are.
Thank you for your help.
Fazlollah
