The effects of process parameters on carbon dioxide reforming of methane over Co–Mo–MgO/MWCNTs nanocomposite catalysts

Abstract

Abstract The activity of the nanocomposite catalysts comprising of as-synthesized multi-walled carbon nanotubes (MWCNTs) with Co–Mo/MgO was studied on carbon dioxide (CO2) reforming of methane (CH4) (CRM) under various experimental conditions. The effects of reaction parameters such as hydrogen reduction, reaction temperature, CH4/CO2 gas feed ratio and gas hourly space velocity (GHSV) on the performance of the Co–Mo–MgO/MWCNTs nanocomposite catalysts were thoroughly investigated from a few aspects such as the CO2 and CH4 conversions, syngas production and resistance towards carbon formation. After 10 h on the stream, CH4 and CO2 conversions of the nanocomposite catalyst decreased by only about 5%; whereas the Co–Mo/MgO catalyst was completely deactivated. Although the catalytic activity and syngas production were not significantly affected after hydrogen reduction, the rate of carbon deposits decreased significantly from 0.084 to 0.074 gc/gcat h. As the reaction temperature increased, the CH4 and CO2 conversions and H2/CO syngas ratio increased while the deposited carbons decreased. The catalytic activity and stability decreased with the GHSV due to coke deposition and other interfering side reaction effects. The reaction temperature of 950 °C at CO2/CH4 ratio of unity was found to be the most appropriate process condition to produce a H2/CO syngas ratio of 1.1 with CH4 and CO2 conversions being 98.6% and 99.1% respectively.