Page 31 - Adsorption Technology & Design, Elsevier (1998)

28 Adsorbents

uptake of the adsorbates is suitable and that the appropriate purities can
be achieved. Again recourse may need to be given to experimentation if
the adsorbent vendor cannot supply the kinetic information. Further in-
formation on equilibria and kinetics is provided in Chapters 3 and 4,
respectively.
Given that the equilibria and kinetics of adsorption are appropriate,
consideration must next be given to the means by which the adsorbent is
going to be regenerated, if it is not to be discarded after use. Depending on
the process application, regeneration can be effected by changing the
pressure and/or the temperature or by some other physical or chemical
alteration to the system. Further information is provided in Chapter 5.
Consideration must also be given to factors such as the strength of the
adsorbent, its chemical resistance, its resistance to coking, etc., as well as to
its availability and price.
Finally, Table 2.5 lists typical applications of common types of adsorbent.
A few of the applications are described in detail in Chapter 7.

Table 2.5 Typical applications of commercial adsorbents

Type Typical applications

Drying of gases, refrigerants, organic solvents, transformer
Silica Gel
oils
Desiccant in packings and double glazing
Dew point control of natural gas
Activated alumina Drying of gases, organic solvents, transformer oils
Removal of HCI from hydrogen
Removal of fluorine and boron-fluorine compounds in
alkylation processes
Carbons Nitrogen from air
Hydrogen from syn-gas and hydrogenation processes
Ethene from methane and hydrogen
Vinyl chloride monomer (VCM) from air
Removal of odours from gases
Recovery of solvent vapours
Removal of SOx and NOx
Purification of helium
Clean-up of nuclear off-gases
Decolourizing of syrups, sugars and molasses
Water purification, including removal of phenol,
halogenated compounds, pesticides, caprolactam,
chlorine