The configuration of a typical adsorption column operated by SMB is shown in
Fig. 9. The adsorber is constituted by a series of chromatographic beds. The different
beds can be grouped in four different zones which are delimitated by the presence of
two different withdrawals (extract and raffinate) and injections (feed and desorbent).
By means of this configuration, the continuous injection and collection of a feed
containing A (the most strongly adsorbed compound) and B (the least strongly
adsorbed) is achievable. In this way A and B are, respectively, recovered in the
extract and the raffinate withdrawals diluted in the desorbent. Obtaining pure
compounds is then straightforward by conventional distillation. As previously
mentioned, the continuous circulation of the liquid is ensured by means of a recycle
stream. The different zones delimitated according to their relative position with
respect to the inlet and the outlet ports are:
1. Zone I between desorbent injection and extract withdrawal: desorption of the
more strongly adsorbed component
2. Zone II between extract withdrawal and feed injection: desorption of the less
adsorbed component
Fig. 9 Schematic representation of a typical SMB configuration
Industrial Zeolite Applications for Gas Adsorption and Separation Processes
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Fig. 9. The adsorber is constituted by a series of chromatographic beds. The different
beds can be grouped in four different zones which are delimitated by the presence of
two different withdrawals (extract and raffinate) and injections (feed and desorbent).
By means of this configuration, the continuous injection and collection of a feed
containing A (the most strongly adsorbed compound) and B (the least strongly
adsorbed) is achievable. In this way A and B are, respectively, recovered in the
extract and the raffinate withdrawals diluted in the desorbent. Obtaining pure
compounds is then straightforward by conventional distillation. As previously
mentioned, the continuous circulation of the liquid is ensured by means of a recycle
stream. The different zones delimitated according to their relative position with
respect to the inlet and the outlet ports are:
1. Zone I between desorbent injection and extract withdrawal: desorption of the
more strongly adsorbed component
2. Zone II between extract withdrawal and feed injection: desorption of the less
adsorbed component
Fig. 9 Schematic representation of a typical SMB configuration
Industrial Zeolite Applications for Gas Adsorption and Separation Processes
211