CO_2 reforming of coke oven gas over a Ni/γAl_2O_3 catalyst to produce syngas for methanol synthesis

摘要

The CO_2 reforming of coke oven gases (COG) was carried out over a Ni/γAl_2O_3 catalyst in order to obtain a suitable syngas for methanol synthesis. The influence of different operating conditions, such as temperature and volumetric hourly space velocity (VHSV), was studied. It was found that the H_2 present in the feed gas promotes the Reverse Water Gas Shift reaction (RWGS), which produces water. Nevertheless, the Ni/γAl_2O_3 catalyst showed a high selectivity to the CO_2 reforming reaction and it was possible to avoid the RWGS under certain operating conditions. Moreover, a part of the reaction could take place via a different path (RWGS followed by the steam reforming of methane instead of the direct dry reforming of methane). The deactivation of the Ni/γAl_2O_3 catalyst was also studied. Both the methane and the carbon dioxide conversions remained steady for 50 h without showing any sign of deactivation. However, the sinterization of the nickel particles and the presence of carbon deposits seemed to indicate that the catalyst would eventually loose catalytic activity.