INVESTIGATION OF THE UNSTEADY PROCESS OF METHANE STEAM REFORMING DURING REGENERATIVE HEATING OF A CATALYTIC INSERT
Steam reforming of methane (SMR) is used to produce more than 45% of the world's hydrogen reserves. The heating of the catalytic insert by the regenerative method for steam reforming of methane is of considerable interest due to the absence of thermal resistance of the reactor wall. PURPOSE. The purpose of this work was to study the operating parameters (distribution of the temperature field and concentrations of the main reactants) of steam reforming of methane in a reactor with regenerative heating of the catalytic insert. METHODS. As a research method, computer simulation in the ANSYS Fluent software product was chosen, which, by solving systems of differential equations using a finite element method, allows visualizing the main characteristics of the process. RESULTS. The maximum concentration of H2 during the course of a chemical reaction is found in the center of the catalysts due to the longer residence time of the reaction mixture. From the initial moment of time to the final one, the hydrogen concentration in the methane conversion products decreased by 39%, and the degree of methane conversion decreased by 38% from 0.23 to 0.143. With an inlet speed of 1.5 m/s of a mixture of steam and methane in the insert cooling cycle and an inlet velocity of the heating gas of 8 m/s in the heating cycle, the insert is cooled much more intensively due to the active absorption of heat. CONCLUSION. As a result of computer simulation of SMR reactions on a preheated catalytic insert, the temperature distribution was determined, as well as the distribution of the mass fraction of the main reagents, the composition of the synthesis gas was revealed at different time intervals. The resulting computer model can be used in the process of designing a SMR reactor operating on a regenerative principle to predict the cooling rate of the catalytic insert during SMR reactions, as well as for its heating rate at different flue gas supply.