Design of multi-component gradient SMBs

Shortcut design method for multicomponent gradient simulated moving beds

“…The concentration of extract components and raffinate components are determined through mass balances 22 . Finally, to determine the maximum , the approach of Frederiksen was used in Equation () 22,24 …”

“…The concept behind gradient SMB is that in sections 1–2, where desorption takes place, a low‐affinity zone is created to lower the affinity of the components to the resin, whereas in sections 3–4, a high‐affinity zone is created. That means two different modifier concentrations are present in sections 1–2 and 3–4 as shown in Figure 1, 1,24 namely extract modifier concentration, , and raffinate modifier concentration, .…”

“…For constant‐selectivity isotherms such as the Langmuir isotherm, explicit expressions for design criteria for all the zones are available 27–30 . For nonconstant selectivity, the lines for constructing the triangular diagram can be determined numerically 6,16,18,24 …”

“…To design a multicomponent isocratic and gradient SMB irrespective of isotherm, we recently 24 proposed a shortcut design method. Here, we provide a more detailed description of the shortcut design method, and its verification is extended to a wider range of systems.…”

“…Finally, the use of the design method is extended by analyzing the performance of gradient SMBs. Specifically, the influence of the modifier concentrations on the gradient SMB performance is investigated using the shortcut design method 24 …”