Packed bed adsorption

1
Packed bed adsorption

• Adsorbent material is packed within a tubular
  vessel (column)
• Feed is sent in from one end while the exit
  stream is monitored for the concentration of the
  target solute
• Adsorption results is depletion of solute from
  the feed as it advances through the column
• Feed flow into the column is stopped when the
  binding capacity of the column is reached
• The unbound material are removed from the column
  by washing with appropriate fluid
• The bound material is desorbed from the adsorbent
  by a process called elution

2
Adsorption, washing and elution
Adsorption
Washing
Elution
y
Time/volume
3
Breakthrough curve
yF
yE
y
yB
tE
tB
Time/volume
4
Concentration profile within packed bed
Time
yF
Time
q f (y)
y
0
0
l
Bed length
5
Adsorption and equilibrium zones
yF
y
0
0
l
Adsorption zone
Equilibrium zone
Bed length
6
Packed bed adsorption equations
General equation
Effluent concentration
Exhaustion time