Study on the durability of a Plate-Type Anodic Alumina Supported Nickel Catalyst for Steam Reforming of Methane

摘要

An anodic alumina supported nickel catalyst with an interfacial nickel aluminate layer (Ni/NiAl2O4/Al2O3/Alloy) was prepared through a double impregnation method. The catalyst provided a high and stable SRM reactivity near the equilibrium value, while no deactivation was observed in the continuous durability testing for 130 h at 700 oC under F/W = 157000 mL/(h gcat). The investigation of the influence of methane and/or steam treatments on the reactivity of Ni/NiAl2O4/Al2O3/Alloy showed the catalyst is remarkably deactivated by the steam treatment. It was also found that there was no difference in the reduction effect between hydrogen and methane to regenerate a steamed catalyst. Furthermore, from the comparison experiment between the anodic nickel catalyst and a commercial nickel catalyst (FCR-4), it was shown that the anodic nickel catalyst is more preferable for SRM. To evaluate its industrialization possibility, Ni/NiAl2O4/Al2O3/Alloy was subjected to an accelerated life test. When the F/W was increased by five-fold up to 785000 mL/(h gcat), the catalyst was seen to deactivate very rapidly. To improve the SRM durability of Ni/NiAl2O4/Al2O3/Alloy, the pH of Ni (II) nitrate aqueous solution was modified with NH4OH. It was shown that the higher pH was preferable for the activity and stability of the catalyst.