Application of absorption

Some of the important applications of adsorption are given below:

1) In gas masks:

Activated charcoal or a mixture of adsorbents is generally used in gas masks to adsorb poisonous and toxic gases from air.

These masks are commonly used by the miners because there are poisonous gases like CO, CH₄ etc. in the atmosphere in the coal mines. Therefore, these masks help to purify the air for breathing.

2) In dyeing of cloth:

Mordants such as alums are used in dyeing of cloth.They adsorb the dye particles which, otherwise, do not stick to the cloth.

3) In Dehumidizers for control of humidity:

Silica and aluminium gels are commonly used to adsorb humidity or moisture from air. 

4) Removal of colouring matter from solutions:

Many substances such sugar, juice and vegetable oils are coloured due to the presence of impurities.They can be decolourised by placing in contact with adsorbents like activated charcoal or fuller’s earth. This method is used in the manufacture of cane sugar. 

5) Heterogeneous catalysis:

Adsorption of reactants on the solid surface of catalysts increases the rate of reaction. The metals such as Fe, Ni, Pt, Pd, etc, are used in the manufacturing process.

Manufacture of ammonia using iron as catalyst (Haber process), manufacture of sulphuric acid by contact process and use of finely divided nickel in the hydrogenation of oils are excellent examples of heterogeneous catalysis.