Absorption is a very common operation in gas purification. The aim of the operation is to transfer a weakly-concentrated compound from a gas phase to the liquid phase. The absorbed compound can physically dissolve in the liquid and may react there chemically. Absorption is therefore a phenomenon whereby a product in gaseous state dissolves into a liquid in the solvent.

Widely used for gas purification, the absorption of a gas by a liquid is a process that allows the mass transfer of a compound from the gas phase to the liquid phase. The physical dissolution of the compound into its liquid phase is carried out in several stages by a stirrer (or static mixer) equipped with a turbine or propeller:
- The compound in gaseous phase is diffused towards the surface of the liquid,
- The agitator causes the compound to condense/dissolve in the liquid phase,
- The absorbed compound is dissolved and diffused into the liquid.



The speed of absorption is favoured by the increase in the level of turbulence of the gas, allowing its presence in contact with the liquid to be rapidly renewed, and vice versa. Thus, the increase in the contact surface between gas and liquid will lead to a faster dissolution of the compound from the gas phase to the liquid phase.
It should be noted that, in the case of gas absorption with chemical reaction, the faster the chemical reaction takes place, the faster the transfer process will be accelerated.



As the absorption process is often accompanied by an increase in temperature, and unlike liquids or solids, the solubility of the gases decreases as the temperature increases. It is therefore necessary to reduce or eliminate this effect so that the liquid can retain its maximum absorption capacity.



Gas absorption is used in the field of purification by allowing the transfer of pollutants from the gas phase to the liquid phase.
It meets the regulatory requirements for the release of gases into the environment.
There are many applications in the treatment of odours (purification plants, rendering workshops, etc.) and solvents in the petrochemical industry,
the ink and paint industry, pharmaceuticals or biotechnologies.



Gas absorption also allows simultaneous treatment of dust and gaseous pollutants.
Moreover, physical absorption (without chemical reaction) is a non-destructive technique that makes it possible, thanks to the regeneration of the liquid, to recycle the polluting species in the process, thus offering both technical and economic benefits

Equipment adapted for the application: Gas absorption :

Turbines


stirrer disc disgaz turbine with notched blades
Turbine Disgaz with notched paddles, dispersion gas and liquids
stirrer rushton disc turbine with vertical blades
Rushton Turbine with Vertical Blade Disc for stirrers
auto-aspirating turbine with double discs and vertical plates
Self-suction turbine for stirrers maixers, dispersion gas liquid stirrer