Dynamic model of a non-linear non-ideal multivariable-coupling hybrid system: simulated moving bed chromatography

Simulated moving bed chromatography (SMBC) is attracting increased interest for separations of pharmaceuticals and fine chemicals. The SMBC process is a mixed discrete and continuous process. It is a non-linear non-ideal multivariable-coupling hybrid system. A detailed model that takes account of non-linear isotherms, mass transfer resistance, extra-column effect, and discrete event of port periodic switching, was developed to simulate the complex dynamics. All design parameters (number, configuration, length and diameter of columns, pre-column dead volume, post-column dead volume, particle size) and operation parameters (switching period, feed concentrations, flow rates of recycling flow, desorbent, extract, feed and raffinate) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, process optimization and advanced control of a SMBC unit.