Towards efficient production of syngas via the CH4 bi-reforming with CO2 over Ni/xMgAl powder and monolithic catalysts

Abstract

In this study, a promising monolithic catalyst composition for the production of syngas using bi-reforming (BRM) of CH4–CO2 mixture was proposed. The BRM performance was evaluated with N2/CH4/H2O/CO2 (1/1/0.8/0.4) mixture at 700–800 °C. First, the influence of MgO loading on the activity of 10 wt.% of Ni supported on xMgAl (x is MgO content, x = 10–40 wt.%) powder catalyst was studied. The addition of 10–20 wt.% of MgO leads to higher reforming performance, probably due to the formation of MgAl2O4 phase that enhance the Ni dispersion. At 800 °C, the CH4 conversion and H2 yield obtained with Ni/20MgAl are 1.7 and 1.5 times, respectively, higher than that of the Ni/Al catalyst. However, higher MgO loading causes a coverage of Ni active sites and decrease activity. Ni/20MgAl powder catalyst exhibit highest activity and this sample was then deposited on monolith substrate. The monolith catalyst shows higher BRM activity than powder form. Long-term test demonstrates high stability of monolith catalyst with less than 5% the losses in CH4 and CO2 conversions after 60 h time on stream. CH4 and CO2 conversion are 89% and 81%, respectively. The H2/CO ratio is near 2, which meets the requirement for methanol/Fischer–Tropsch fuel synthesis.