Parametric study of catalytic dry reforming of methane for syngas production at elevated pressures

This study examined and elucidated the catalytic dry reforming of methane (DRM) for synthesis gas (syngas) production. The DRM performance was characterized using CH4 and CO2 conversions and product yields under various operating conditions and reactant compositions. A fixed-bed tubular reactor was used as the physical model and axisymmetric non-isothermal governing equations for the gas flow, energy transfer and species transport were solved numerically. The reactant inlet temperature was used as the primary parameter. Good agreement between the numerically predicted and experimentally measured data was obtained as the carbon formation reactions were included. A carbon-free reaction was obtained from the numerical model at high temperature which agreed with the thermodynamic equilibrium analysis. It was found that the DRM performance was degraded as the reaction pressure and reactant flow rate were increased. Under these conditions, carbon yield increases with the increase in pressure and reactant flow rate. It was also found that DRM performance can be enhanced by introducing excessive CO2 into the reaction system. Carbon formation was suppressed by the excessive CO2 supply. The numerical results also indicated that decreases in CO2 and CH4 partial pressures led to enhance the DRM performance. The addition of H2 as one of the reactants suppresses CH4 conversion and inhibited carbon formation while the addition of CO resulted in suppressing CO2 conversion and enhancing carbon formation.