Adsorption-absorption of gases in solution
Submitted by: Kainat Sher
Submitted to: Dr. Naila Zubair
BS Chemistry (VIII)
Session 2019-2023
Date : 04 may 2023
Department of Chemistry Women University Mardan
1
, INTRODUCTION:
Gas liquid interface are all around us. In biological chemistry, oxygen and carbon dioxide
molecules partition in and out of the blood stream with every breath we take. In environmental
chemistry, carbon dioxide dissolves in sea water and lower pH of the ocean. In industrial
chemistry, the ancient Sumerians synthesized surface active molecules as far back as 2200BCE.
All these systems represent unique avenues for chemical reactions; because of their inherit
asymmetry at surfaces, the chemical and physical properties of gas- liquid interface differs from
those of bulk gases and bulk liquids.
For over 100 years chemical engineers have been interested in the factors that govern the rate of
absorption of gases in liquids. In about 1830, for instance, William Gossage filled a derelict
windmill with brushwood and ran water over it to absorb hydrochloric acid vapors from
manufacture of alkali. This perhaps marks the invention of first practical absorption tower. The
principle incidentally, was protected by British patent of 1836.
In chemical and process industries there are many occasions on which a gas must be absorbed by
a liquid. It may be defined as,
Gas absorption-adsorption (also known as scrubbing) is an operation in which a gas
mixture comes in contact with a liquid for purpose of preferentially dissolving one or more
components of the gas mixture and to provide a solution of them in liquid.
Therefore we can see that there is a mass transfer of the component of gas from the gas phase to
the liquid phase. The solute so transferred is said to be absorbed by liquid.
In gas desorption (or stripping) the mass transfer is in the opposite direction, i.e. from the liquid
phase to the gas phase. The principle for both systems is same. For simple case only one
component of the gas mixture is assumed to be absorbed. The other components are of the gas
are assumed to be non-soluble in the liquid (i.e. the other gas components are inert) and the
liquid is non-volatile, which means that there is no transfer of molecules from liquid to gas
phase. The process of gas absorption thus involved the diffusion of solute from gas phase
through stagnant or non-diffusing liquid.
A few examples will illustrate their diversity.
Absorption of nitrous gases in water or nitric acid, during nitric acid manufacturing.
Absorption of oxygen by fermentation broths.
Removal of carbon dioxide from water gas by absorption in solutions of alkalis or amines
Removal of carbon monoxide from water gas by absorption in solutions of copper
complexes.
2
Submitted by: Kainat Sher
Submitted to: Dr. Naila Zubair
BS Chemistry (VIII)
Session 2019-2023
Date : 04 may 2023
Department of Chemistry Women University Mardan
1
, INTRODUCTION:
Gas liquid interface are all around us. In biological chemistry, oxygen and carbon dioxide
molecules partition in and out of the blood stream with every breath we take. In environmental
chemistry, carbon dioxide dissolves in sea water and lower pH of the ocean. In industrial
chemistry, the ancient Sumerians synthesized surface active molecules as far back as 2200BCE.
All these systems represent unique avenues for chemical reactions; because of their inherit
asymmetry at surfaces, the chemical and physical properties of gas- liquid interface differs from
those of bulk gases and bulk liquids.
For over 100 years chemical engineers have been interested in the factors that govern the rate of
absorption of gases in liquids. In about 1830, for instance, William Gossage filled a derelict
windmill with brushwood and ran water over it to absorb hydrochloric acid vapors from
manufacture of alkali. This perhaps marks the invention of first practical absorption tower. The
principle incidentally, was protected by British patent of 1836.
In chemical and process industries there are many occasions on which a gas must be absorbed by
a liquid. It may be defined as,
Gas absorption-adsorption (also known as scrubbing) is an operation in which a gas
mixture comes in contact with a liquid for purpose of preferentially dissolving one or more
components of the gas mixture and to provide a solution of them in liquid.
Therefore we can see that there is a mass transfer of the component of gas from the gas phase to
the liquid phase. The solute so transferred is said to be absorbed by liquid.
In gas desorption (or stripping) the mass transfer is in the opposite direction, i.e. from the liquid
phase to the gas phase. The principle for both systems is same. For simple case only one
component of the gas mixture is assumed to be absorbed. The other components are of the gas
are assumed to be non-soluble in the liquid (i.e. the other gas components are inert) and the
liquid is non-volatile, which means that there is no transfer of molecules from liquid to gas
phase. The process of gas absorption thus involved the diffusion of solute from gas phase
through stagnant or non-diffusing liquid.
A few examples will illustrate their diversity.
Absorption of nitrous gases in water or nitric acid, during nitric acid manufacturing.
Absorption of oxygen by fermentation broths.
Removal of carbon dioxide from water gas by absorption in solutions of alkalis or amines
Removal of carbon monoxide from water gas by absorption in solutions of copper
complexes.
2
