Determination of the operating range of CO₂ conversion and syngas production in dry auto-thermal reforming

A porous medium-catalyst hybrid reformer for CO₂ conversion by dry auto-thermal reforming (DATR) was investigated in this study, and its operating range was discovered. The hybrid design was used to enhance the oxidative heat release by internal heat recirculation during exothermic reaction conditions, thereby increasing the CO₂ conversion efficiency. The experimental results show that the CO₂ conversion could be enhanced with higher catalyst inlet temperatures. The examination of the operating range of DATR showed that the CO₂ conversion efficiency increased at higher reaction temperatures and CO₂/CH₄ ratios (≧1). Moreover, DATR in high temperature conditions must be carried out with high O₂/CH₄ ratios. Under these conditions of high oxygen content, CO₂ generation and reduction reactions occur simultaneously. Overall, optimal CO₂ conversion can be obtained with an O₂/CO₂ ratio of approximately 0.5. At these conditions, CO₂ conversion efficiency can reach approximately 13% without external heat addition.