Numerical Study of Wave Processes during Oxidative Regeneration of a Stationary Catalyst Layer

An The article is devoted to the study of the heat waves formation and the combustion front propagation in a stationary catalyst layer during the burning of coke sedimentation based on a mathematical model. Two modes of the process management are investigated: stationary (boundary conditions for temperature and concentration of reagents in the reaction mixture are constant) and dynamic (temperature and composition of the reaction mixture are non-stationary). The mathematical model is described by equations of mathematical physics and ilcludes diffusion, convection and chemical reactions in the pores of the catalyst grain, heat and mass transfer in the gas flow, heat propagation through the catalyst skeleton and heat and mass transfer between the catalyst and the gas. The explicit-implicit computational algorithm is based on the integro-interpolation method using the principle of splitting by physical processes: chemistry problems are solved by the three-stage Runge–Kutta method of the fifth accuracy order, hyperbolization is used to calculate diffusion fluxes, convection is calculated conservatively. The transfer equations and third-kind boundary conditions are approximated implicitly. The article presents the results of serial calculations for various initial and boundary conditions to study the heat waves formation and the combustion front propagation along the catalyst.