Oxy-CO2 Reforming of Methane to Syngas over CoOx/CeO2/SA-5205 Catalyst

Abstract

The oxy-CO 2 methane reforming (OCRM) process has been investigated over the CoO x /CeO 2 /SA-5205 catalyst at varying reaction temperatures (750-900 °C), O 2 /CH 4 ratios (0.3-0.45), and space velocities (20 000-100 000 cm 3 /g/h). With an increasing OCRM reaction temperature, the contribution from the CO 2 methane reforming reaction increased while that from methane combustion reactions decreased. Correspondingly, there was an increase in the H 2 /CO ratio and a sharp decrease in reaction exothermicity. At 900 °C (gas hourly space velocity = 46 000 cm 3 /g/h and O 2 /CH 4 = 0.4), the OCRM reaction over the CoO x /CeO 2 /SA-5205 catalyst was mildly endothermic with >90% CH 4 conversion, >95% H 2 selectivity, and a H 2 /CO ratio of 1.63. CH4 conversion was relatively unaffected by the O 2 /CH 4 ratio used in the OCRM reaction; however, CO 2 conversion decreased on increasing the O 2 /CH 4 ratio. While H 2 selectivity was not significantly affected by the O 2 /CH 4 ratio, the H 2 /CO ratio increased linearly with an increasing O 2 /CH 4 ratio. The endothermicity of the reaction was found to decrease with an increasing CH 4 /O 2 ratio, which can be explained on the basis of increased contribution from the methane partial oxidation reaction with an increasing O 2 /CH 4 ratio.