Aerospace Instrument-Making Annotation << Back Mathematical Model of the Regenerative Cartridge in Isolation Breathing Apparatus: Coupled Mass, Heat, and Sorption Processes Gomzov N.V., Slezin K.A., Gromov Yu.Yu., Pogonin V.A. The article focuses on the development of a mathematical model for a regenerative cartridge based on chemically bound oxygen (KO2 ), which is a key component of an isolating breathing apparatus (IBA). The model describes a complex of interrelated processes in a granular sorbent bed: mass transfer (CO2 sorption, O2 generation), heat transfer, and gas fl ow hydrodynamics. The mathematical formulation includes a system of equations for component material balance, sorption kinetics (Trepnel's equation), heat balance for sorbent granules and the gas mixture, momentum conservation (Kozeny–Carman), and the ideal gas law. Models for calculating the physical properties of the multicomponent gas mixture (viscosity, thermal conductivity, heat capacity) are incorporated. The model enables forecasting the dynamics of gas concentration changes, temperature fi elds, and the protective duration of the cartridge under various operational regimes. The proposed approach provides a basis for optimizing the design parameters of regenerative cartridges and reducing the scope of costly full-scale experiments. Keywords: isolation breathing apparatus, regenerative cartridge, sorption processes, mathematical modeling, mass transfer, heat transfer. DOI: 10.25791/aviakosmos.11.2025.1519 Pp. 40-45.