Physical gas absorption into a stirred liquid: a new kinetic model and experimental studies

• Published in: Heat and mass transfer 2023-08, Vol.59 (8), p.1397-1408
• Main Authors: Madygulov, M. Sh, Vlasov, V. A.
• Format: Article
• Language: English
• Subjects: Absorptivity; Carbon dioxide; Chemical reactions; Desorption; Dissolved gases; Engineering; Engineering Thermodynamics; Gas absorption; Gas-liquid systems; Heat and Mass Transfer; Industrial Chemistry/Chemical Engineering; Kinetics; Mathematical models; Methane; Original Article; Temperature dependence; Thermodynamics
• ISSN: 0947-7411; 1432-1181
• DOI: 10.1007/s00231-023-03346-y

We presented a new analytic model of physical gas absorption into a stirred liquid. This model is based on the assumption that the gas absorption/desorption process can be considered as a reversible chemical reaction that occurs at the gas–liquid interface. In addition, in this model, there is no assumption about the distribution of the concentration of the dissolved gas inside the liquid during its intensive stirring. In the framework of the presented model, it is shown that the physical absorption coefficient is the rate constant of the desorption reaction. This quantity is individual for each specific gas–liquid system, it does not depend on concentrations, and its temperature dependence obeys the Arrhenius equation. Experiments were carried out to study the kinetics of physical absorption of methane into stirred water at different temperatures and methane pressures. Experiments were also carried out to study the kinetics of physical absorption of carbon dioxide into stirred water at different temperatures and carbon dioxide pressures. The obtained experimental data fully confirmed the validity of the proposed model. The dependences of the rate constant of the desorption reaction (physical absorption coefficient) on temperature for the methane–water and carbon dioxide–water systems were determined.