1. MASS TRANSFER OPERATION
BRANCH -
CHEMICAL (5TH SEM )

2. ABSORPTION WITH CHAMICAL REACTION
BARAD MAHUL
JAIMIN CHAVDA –
GOHIL ROHIT –
MISTRY AVI –
PANCHAL AATISH –

3. INRODUCTION
Absorption, or gas absorption, is a unit operation used in the chemical industry to separate gases by washing or scrubbing a gas mixture with a suitable liquid .
The fundamental physical principles underlying the process of gas absorption are the solubility of the absorbed gas and the rate of mass transfer.
One or more of the constituents of the gas mixture dissolves or is absorbed in the liquid and can thus be removed from the mixture.
In some systems, this gaseous constituent forms a physical solution with the liquid or the solvent, and in other cases , it reacts with the liquid chemically.

4. In some systems, this gaseous constituent forms a physical solution with the liquid or the solvent, and in other cases , it reacts with the liquid chemically.
The purpose of such scrubbing operations may be any of the following : gas purification (eg , removal of air pollutants from exhausts gases or contaminants from gases that will be further processed) , product recovery , or production of solutions of gases for various purposes.
The absorber may be a packed column , plate column , spray column , venturi scrubbers , bubble column , falling films , wet scrubbers ,stirred tanks

5. TRAY COLUMN

6. TRAY COLUMNS
Tray absorbers are used in applications where tall columns are required, because tall, random-type packed towers are subject to channeling and maldistribution of the liquid streams.
Plate towers can be more easily cleaned. Plates are also preferred in applications having large heat effects since cooling coils are more easily installed in plate towers and liquid can be withdrawn more easily from plates than from packings for external cooling.
Tray columns are used in a refinery dehexanizer to decrease the benzene content in the naptha feed to the process. This results in lower automobile exhaust emissions.

7. PACKED COLUMN

8. PACKED COLUMN
Packed columns are used mostly in air pollution control..
The water soluble ethylene gas ishydrolyzed to ethylene gylcol.
Packed columns are also used in the chemical ,petrochemical,food, pharmaceutical,paper, and aerospace industries.

9. Its convincing advantages and disadvantages is following: -
Advanges
High efficiency of absorption drop
Low outlet temperature
No need after-cooling
Low flow resistance
Easy maintenance
Disadvanges
Restricted by pressure
Film breakup
Flooding

10. SPRAY COLUMN

11. Spray columns are differetal contactors.
The liquid stream enters the coloumn through one or more spray nozzles at different heights in the column.
The droplets formed provide a large surface area for exposure to the gas stream,with smaller droplets resulting in a greater Exchange area.
The liquid and gas streams can flow counter-currently or in paralel. An optimum droplet velocity is essential because low velocity will lead to low contact or turbulence and high velocity may cause flooding.