DIFFERENCES BETWEEN ADSORPTION AND ABSORPTION

 ADSORPTION AND ABSORPTION

Adsorption and absorption are both sorption processes.

Absorption occurs when atoms pass through or enter a bulky material. During absorption, the molecules are entirely dissolved or diffused in the absorbent to form a solution. Once dissolved, the molecules cannot be separated easily from the absorbent.

DIFFERENCES BETWEEN ADSORPTION AND ABSORPTION

	Absorption	Adsorption
Definition	Assimilation of molecular species throughout the bulk of the solid or liquid is termed as absorption.	Accumulation of the molecular species at the surface rather than in the bulk of the solid or liquid is termed as adsorption.
Phenomenon	It is a bulk phenomenon	It is a surface phenomenon.
Heat exchange	Endothermic process	Exothermic process
Temperature	It is not affected by temperature	It is favoured by low temperature
Rate of reaction	It occurs at a uniform rate.	It steadily increases and reach to equilibrium
Concentration	It is same throughout the material.	Concentration on the surface of adsorbent is different from that in the bulk

Gas-liquid absorption (a) and liquid-solid adsorption (b) mechanism. Blue spheres are solute molecules

Adsorption is generally classified into physisorption (weak van der Waal’s forces) and chemisorption (covalent bonding). It may also occur due to electrostatic attraction. The molecules are held loosely on the surface of the adsorbent and can be easily removed.

Uses

Absorption:The common commercial uses of absorption cycle are absorption chillers for space cooling applications, ice production, cold storage, turbine inlet cooling. High efficiency operation, environmentally friendly refrigerants, clean-burning fuels and few moving parts that require maintenance make absorption a very good choice for consumers.

The process of gas absorption by a liquid is used in hydrogenation of oils and carbonation of beverages.