Application of Adsorption
The phenomenon of adsorption finds a number of applications. Important applications are given as follows.
(1) Production of high vacuum
(2) In Gas masks :This apparatus is used to adsorb poisonous gases (e.g. oxide of sulphur etc.) and thus purify the air for breathing.
(3) For desiccation or dehumidification : These substances can be used to reduce/remove water vapours or moisture present in the air. Silica gel and alumina are used for dehumidification in electronic equipment.
(4) Removel of colouring matter from solution : (i) Animal charcoal removes colours of solutions by adsorbing coloured impurities. (ii) Animal charcoal is used as decolouriser in the manufacture of cane sugar.
(5) Heterogeneous catalysis : Mostly heterogeneous catalytic reactions proceed through the adsorption of gaseous reactants on solid catalyst. For example,
(i) Finely powdered nickel is used for the hydrogenation of oils.
(ii) Finely divided vanadium pentaoxide is used in the contact process for the manufacture of sulphuric acid.
(6) Separation of inert gases : Due to the difference in degree of adsorption of gases by charcoal, a mixture of inert gases can be separated by adsorption on coconut charcoal at different low temperatures.