La-promoted Ni/gamma-Al2O3 catalyst for autothermal reforming of methane

Abstract

Autothermal reforming (ATR) of methane over the synthesized catalysts of 10Ni-2La/gamma-Al2O3, 10Ni-2Ce/gamma-Al2O3, 10Ni-2Co/gamma-Al2O3 was investigated in the temperature range of 600-800 oC for the hydrogen production. The sequence of 2 wt% metal loading on nickel alumina support in relation to their catalytic performance was observed as La > Ce > Co. The excellent activity and selectivity of 10Ni-2La/gamma-Al2O3 was superior to other catalysts owing to little carbon deposition (similar to 2.23 mg coke/gcath), high surface area and good dispersion and stability in the alumina support. The reforming of methane was inferred to be initiated by the decomposition of hydrocarbon at the inlet zone, preceded by the reforming reactions in the catalyst bed. Our result shows that it can be possible to achieve the H-2/CO ratio optimal to the GTL processes by controlling the O-2/CH4 ratio of the feed inlet. The addition of oxygen to the feed inlet enhanced conversion efficiency substantially; probably, it favors the re-oxidation of carbonaceous residues formed over the catalyst surfaces, avoiding the catalyst deactivation and hence promoting catalyst stability.