Breakthrough of Multicomponent Adsorbate Systems

When multicomponent adsorbates are contained in the fluid entering an adsorbent bed, breakthrough behavior becomes more complicated than in single component systems. Analysis of multicomponent adsorption is necessary in many cases but two typical situations may be of concern. One situation is related to the separation of mixtures. When separation of two or more components is necessary, the behavior of each component in the column must be described as precisely as possible The other situation is encountered in the purification of water or air which contains many unknown pollutants In this case, prediction of the global behavior of the column may be necessary. 

When weakly adsorbed Component 1 and strongly adsorbed Component 2 are contained in the fluid entering an adsorbent column. Component 1 weakly adsorbed is replaced by the stronger Component 2 then Component 1 proceeds in the column faster than Component 2. In this case, after a certain length of traveling path, the concentration profiles of the two components are established as shown m Fig. 7.12.a-c. The established profiles of the concentrations are discussed by division into four zones. 

In Zone IV, the amounts of both components adsorbed on adsorbent are in equilibrium with the concentrations of both components in the 

The concentration levels at Zones II and IV and the length of each zone can be obtained as follows. 

When adsorption is assumed to take place in equilibrium mode, concentration profiles in the bed may become as shown in Fig. 7.l2.d, where the lengths of Zones I and 111 become inflnitesmally small. 

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