The catalytic methanation of coke oven gas over Ni-Ce/Al2O3 catalysts prepared by microwave heating: Effect of amorphous NiO formation

Ni-Ce/gamma-Al2O3 catalysts were prepared by traditional and microwave heating and tested by the methanation of simulated coke oven gas in a fixed bed reactor. Various characterization techniques were used to examine the bulk and surface properties of the catalysts. The catalysts obtained by microwave heating show superior methanation activity to traditional catalysts. Conversion of 100% CO, CO2, and O-2, with part conversion of C2H6, was obtained on the MO-15NC catalyst with the following reaction conditions: 260 degrees C, 3.0 MPa and 20,000 mL g(-1) h(-1) weight hourly space velocity. The temperature gradient between the NiO and the alumina support caused by the difference in microwave energy absorption promotes the formation of a large amount of highly dispersed amorphous NiO with a Ni loading of less than 15 wt%, and is more active for the methanation reaction because of a weak interaction with the support, large active surface area and low CO dissociation energy. (C) 2014 Elsevier B.V. All rights reserved.