GENERAL CONTROL OF GASES AND VAPORS

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GENERAL CONTROL OF GASES AND VAPORS
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ADSORPTION
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Adsorption Requirements
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Flow Diagram
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http//www.csmworldwide.com/carbon.htm
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Physical Properties of Adsorbents
Adapted from Cooper and Alley (2002)
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Activated carbon from various sources
From Cooper and Alley (2002)
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Pore Structure of Activated Carbon
Macropores (accessible to solvent and solute)
Internal porosity
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(No Transcript)
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ADSORPTION ISOTHERMS
Wads f (P,T)
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Favorable and Unfavorable Adsorption
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Temperature Effect on Adsorption
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Linear (Henrys )Isotherm
Wads KH P
Wads
KH
P
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Freundlich Isotherm
Wads KF P 1/n
ngt1
n 1
1/n
ln Wads
Wads
nlt1
ln KF
P
ln P
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Freundlich Isotherm Parameters
Available for a wide variety of organic vapors on
various activated carbon types
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Langmuir Isotherm
1
?
b
0
P
S1/Wmax
P/Wads
I1/bWmax
P
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Brauner-Emmett-Teller (BET) Isotherm
Wads
for n ? ?
P
for finite n
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BET isotherm - continued
S (C-1)/CWmax
I 1/CWmax
P/Po
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Empirical equations for adsorption
1. Correlation using a logarithmic series
expansion such as
Note that a, b and c are constants specific to a
typical compound (Table on p. 301)

• Method of Grant and Manes (1966) relate
  fugacity ratio in gas phase

to the volume adsorbed on solid. Polanyi
Adsorption Potential
These plots are available in Perrys ChE Handbook.
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Adsorption Potential Plot - Example