Investigating the influence of operating conditions on the combined steam and carbon dioxide reforming of methane performance in the presence of Ni/ZrO2 catalyst

In the present study, Ni/ZrO2 catalyst was synthesized via co-precipitation approach and its catalytic activity was evaluated in combined steam and carbon dioxide reforming of methane (CSCRM) reaction at a temperature range of 773 K–1273 K, CO2:H2O ratio of 0.5-3 and (CO2 + H2O)/CH4 ratio of 0.5-3. The results demonstrated that the higher (CO2+H2O)/CH4 ratio and temperature were required for CH4 conversion about 100%. The effect of CO2/H2O ratio was little on the CO and H2 yield. A (CO2+H2O)/CH4 ratio of 1.5 associated with CO2/H2O ratio of 0.5 at the minimum temperature of 1073 K were the required reaction conditions for the synthesis gas (syngas) formation with H2/CO ratio about 2. The temperature, type and amount of the oxidizing agent greatly affected on the amount of coke deposition. The least temperature of 1073 K and (CO2+H2O)/CH4 ratio higher than 1.5 irrespective of CO2:H2O ratio was obtained as a proper operation conditions to avoid coke formation. Moreover, CO2 revealed a higher portion than H2O in coke formation in CSCRM reaction.