Graphical method to obtain multicomponent adsorption equilibria from intermediate breakthrough curve plateaus

Adsorption mixture equilibrium data remains challenging to obtain. An established technique is the adsorption breakthrough experiment where the final adsorbed capacities are determined. A graphical method to obtain adsorbed amounts from the intermediate plateaus in the breakthrough curves is proposed in this work. The method is proposed for isothermal, diluted breakthrough tests. Via an integrated capacity curve, the intermediate regions can be extrapolated to extract additional equilibrium points beyond the final state without the need for a multicomponent model. If the column is preloaded, the extra equilibrium points can correspond to multicomponent mixtures as multiple species can have non-zero intermediate concentration plateaus. The method is demonstrated on various simulated examples and then applied on breakthrough data from non-preloaded and preloaded columns of all-silica beta zeolite for diluted methanol/ethanol and diluted ethanol/isobutanol mixtures.