Abstract
Diffusion processes in gases play an important role in many areas of Chemical Technology, aerodynamics, Astrophysics and Applied Physics. The study of diffusion phenomena in multicomponent gas mixtures at different pressures and temperatures makes it possible to understand the mechanisms of mass transfer between components and their effect on the final separation products. This study is aimed at describing the features of diffusion mixing of gases during the transition from molecular diffusion to the zone of concentration gravitational convection. This study is aimed at studying the processes of diffusion and convective mixing in tricomponent gas mixtures. According to the results of the study, it was found that convective flows significantly exceed molecular diffusion. The Biolab method was used, the diffusion mixing of tricomponent gas mixtures was analyzed and the formation of concentration convection in the diffusion cell channel in the gravity field was demonstrated. Mathematical models have been proposed to describe diffusion and convective mixing at different pressures and initial concentrations. In addition, the results of the study, which revealed the dependence of convective flows on pressure and temperature in the helium-propane-methane system, confirmed the violation of mechanical equilibrium. Conditions for the formation of diffusion stability in propane-hydrogen-carbon dioxide and propane-heliumcarbon dioxide systems were considered. The results show the influence of thermodynamic parameters on the formation of diffuse mixing and convective flows. The study proves the possibility of Molecular and convection mixing in gas mixtures consisting of components with similar densities.