Experimental Study of the Temperature Rise in the Frontal Layer of a Structured Porous Metal Catalyst in Air Conversion of Methane

Resumo

Heat-resistant Ni/MgO block catalysts have been developed on porous nickel carriers for the air conversion of natural gas to synthesis gas. The catalysts were tested under normal pressure, which allowed one to select of a number of samples that demonstrate relatively the low temperature of the frontal layer of the catalytic block of 880–940°C at the inlet temperature of the mixture of 20°C and excess air factor of 0.3. The composition of the mixture at the outlet remained close to thermodynamic equilibrium at a volumetric flow rate of up to 49 000 h^–1. It was experimentally established that the temperature of the frontal layer decreases with increasing pressure (2–6 atm), an increase in the frontal layer temperature with an increasing coefficient of excess air (0.31–0.42) and the rate of the inlet mixture (0.30–0.74 m/s). This made it possible to obtain approximate estimates of the areas of exothermic and endothermic reaction stages taking into account external diffusion inhibition based on the analysis of the heat balance equation for the frontal layer of the catalyst.