Multistage countercurrent operations adsorption

The problems posed by the motion of solid particles or a moving bed of particles in countercurrent adsorption processes have led to a number of different operational configurations. In a gas-fluidized multistage countercurrent adsorber, there are multiple sieve-tray plates in a vertical column. The adsorbent particles are fluidized by the gas stream to be cleaned entering through the perforations in the sieve tray. The fluidization level is not very vigorous. 

These operations are all similar in that the mixture to be separated is brou t into contact with another insoluble phase, the adsorbent solid, and the unequal distribution of the ori al constituents between the adsorbed phase on the solid surface and the bulk of the fluid then permits a s aration to be made. All the techniques previously found valuable in the contact of insoluble fluids are useful in adsorption. Thus we have batchwise single-stage and continuous multistage separations and separations analogous to countercurrent absorption and stripping in the field of gas-liquid contact and to rectification and extraction with the use of reflux. In addition, the rigidity and immobility of a bed of solid... 

Often if countercurrent adsorption is carried out, it may be of the multistaged type like that in Figure 8.1.43(a), or the Cloethe-Streat type or other configurations. The operating line for such operation may be developed following Section 8.1.2.6 for gas absorption. As shown in Figure 8.1.44(c), for a gas-solid system, for example, a mass balance for species 1 between the top and the nth plate leads for a dilute system to a linear relation between and Wb at the bottom... 

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