Carbon Deposition on Supported Nickel Catalysts for Carbon Dioxide Reforming of Methane.

Abstract

During our screening study on CO 2 reforming of CH 4 over supported Ni catalysts, a serious pressure drop followed by plugging of the reactor was observed on the SiO 2 -supported Ni catalyst while its catalytic activity was almost constant. The change in pressure drop in the reactor was measured under different reaction conditions during the run to determine the plug-free reaction conditions. It was confirmed by thermogravimetric analysis that the increase in pressure drop was caused by carbonaceous deposition. Further experiments were carried out in a flow of CH 4 to accelerate the rate of carbonaceous deposition. Furthermore, the rates of plugging and carbonaceous deposition were related to several kinds of supported Ni catalysts. The increase in pressure drop for the same level of carbonaceous deposition became less for the catalyst of smaller Ni diameter. A macro-porous ceramic support of high porosity reduced the pressure drop caused by carbonaceous deposition. It was suggested that this support would be more effective also with smaller Ni particles.