This document discusses adsorption and fixed bed adsorbers. It defines adsorption as a surface phenomenon where components of a gas or liquid concentrate on the surface of solid particles. There are four main types of adsorption: exchange, physical, chemical, and non-specific. Adsorption is commonly used to isolate products from dilute solutions in fields like medicine, wastewater treatment, and chromatography. Properties of ideal adsorbent materials include high surface area and fine porous structures. Adsorption isotherms describe the equilibrium between adsorbed and unadsorbed phases and are important for predicting adsorber performance and selecting appropriate adsorbents. Key performance characteristics of fixed bed adsorbers include

1. ADSORPTION –PERFORMANCE OF FIXED
BED ADSORBERS-ENGINEERING ANALYSIS-
CHROMATOGRPHY-MIGRATION AND
SPREADING
MAHESHKUMAR.P
2021017024
MANISHA
2021017025

2. Adsorption is a surface phenomenon whereby components of a
gas or liquid are concentrated on the surface of solid particles
or at fluid interfaces. Adsorption is the result of electrostatic,
vander Waals, reactive or other binding forces between
individual atoms, ions or molecules.
Four types: of adsorption can be distinguished: exchange,
physical, chemical and non-specific.
Adsorption serves the same function as extraction in isolating
products from dilute fermentation liquors. Adsorption
operations generally have higher selectivity but
smaller capacity than extractions.
ADSORPTION

3. Adsorbate refers to the molecular species that gets adsorbed
on the surface, whereas adsorbent refers to the surface on
which adsorption happens.
The ideal adsorbent material has a high surface area per unit
volume; this can be achieved if the solid contains a network of
fine internal pores which provide an extremely large internal
surface area.
Commercially adsorbents are porous granular or
gel resins with void volumes of 30-50% and pore
diameters generally less than 0.01 mm.

4. • medical and pharmaceutical products.
• Ion-exchange
• adsorption is established practice for recovery of
amino acids,
• proteins, antibiotics and vitamins.
• Adsorption onto activated charcoal is a method of
long standing for purification of citricacid;
• adsorption of organic chemicals onto charcoal or
porous
• polymeric adsorbents is common in wastewater
treatment.
APPLICATIONS

5. •Adsorption isotherms are useful for selecting the most
appropriate adsorbent; they also play a crucial role in
predicting the performance of adsorption systems.
When an adsorbate and adsorbent are at equilibrium
there is a defined distribution of solute between solid
and fluid phases and no further net adsorption occurs.
Adsorption equilibrium data are available as adsorption
isotherms.
For adsorbate A,an isotherm gives the concentration of
A in the adsorbed phase versus the concentration in the
unadsorbed phase at a given temperature.
ISOTHERM

6. 𝐶𝑎𝑠- the equilibrium concentration or loading
of A on the adsorbent in units of, e.g. Kg
solute 𝐾𝑔−1
solid or kg solute 𝑚−1
solid.
𝐶𝑎𝑠𝑚 -is the maximum loading of adsorbate
corresponding to complete monolayer
coverage of all available
adsorption sites
𝐶𝑎 ∗ − is the equilibrium concentration of
solute
𝐾- Constant

7. Langmuir adsorption is applicable to
systems where:
(i) adsorbed molecules form no more than a monolayer on the surface
(ii) each site for adsorption is equivalent in terms of adsorption energy
(iii) there are nointeractions between adjacent adsorbed molecules.

8. Freundlich isotherm- its widespread use in liquid-solid system
• If adsorption is favourable n is > 1
• if adsorption is unfavourable n is < 1
APPLICATION:wide variety of antibiotics,
hormones and steroids

9. Performance Characteristics of
Fixed-Bed Adsorbers

10. Relationship between the breakthrough curve, loss of solute in the
effluent, and unused column
capacity

11. Fixed-bed adsorber for mass-balance
analysis.

12. Void fraction()
Interstial liquid velocity (u)
Vt –total volume of the column
Vs –volume of the resin particles
Fl –volumetric liquid flow rate
Ac –cross section area of the column
U –interstitial liquid velocity

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