Steam and oxysteam reforming of methane to syngas over Cox Ni1−x O supported on MgO precoated SA‐5205

Abstract

AbstractCatalytic steam and oxysteam reforming of methane to syngas studied involves coupling of exothermic oxidative conversion and endothermic steam‐reforming processes over Cox Ni1−x O (x = 0.0–0.5) supported on MgO precoated commercial low surface area (<0.01 m2 g−1) macroporous silica‐alumina SA‐5205 catalyst carrier. The influence of the Co/Ni ratio of the catalyst on its performance in steam and oxysteam reforming processes (at 800 and 850°C) was studied. For the steam reforming process, the Co/Ni ratio influences strongly on the methane and steam conversion and CO selectivity and product H2/CO ratio, particularly at lower temperature. When the Co/Ni ratio is increased, the methane and H2 O conversion and CO selectivity are decreased markedly. For the oxysteam reforming process, the influence of the Co/Ni ratio on the performance is smaller and depends on process conditions. When the Co/Ni is increased, the methane conversion passes through a maximum at the Co/Ni ratio of 0.17. The influence of the reaction temperature (800 and 850°C) and CH4/O2 and CH4/H2 O ratios on the conversion, selectivity, H2/CO product ratio, and net reaction heat (ΔHr ) was studied in the oxysteam reforming (at space velocity of 47,000 cm3·g−1·h−1) over the catalyst with an optimum Co/Ni ratio (0.17) and a higher Co/Ni ratio (1.0). The oxysteam reforming process involves coupling the exothermic oxidative conversion of methane and the endothermic methane steam reforming reactions, making the process highly energy‐efficient and nonhazardous. This process can be made thermoneutral, mildly exothermic, and mildly endothermic by manipulating process conditions.