Energy efficient conversion of methane to syngas over NiO-MgO solid solution

Abstract

Methane-to-CO and H₂ conversion reactions, involving partial oxidation by O₂, oxy-steam reforming, oxy-CO₂ reforming, CO₂ reforming, simultaneous steam and CO₂ reforming, over a NiO-MgO solid solution (Ni/Mg =0.5) have been investigated. The calcination (up to 1200°C) temperature of the catalyst has a small but significant effect on its activity/selectivity in the oxidative conversion of methane to syngas. The reduction (by H₂) temperature of the catalyst has no significant effect on the catalyst's performance. The catalyst shows high activity and selectivity in the oxy-steam reforming and oxy-CO₂ reforming reactions, at 800-850°C and high space velocity [(40-50)×10³ cm³ g^-1 h^-1]. These two processes involve coupling of the exothermic oxidative conversion and endothermic steam or CO₂ reforming reactions, making both the processes highly energy efficient and also safe to operate. The catalyst also shows high methane conversion activity (nearly 95% conversion) with 100% selectivity for both CO and H₂ in the simultaneous steam and CO₂ reforming of methane at (800-850°C) at a high space velocity (3.6×10³ cm³ g^-1 h^-1).