Oxidative dry reforming of methane over a nickel-alumina catalyst for carbon free operation

A nickel-alumina catalyst, possessing strong metal-support interaction, showed significant CH4 and CO2 conversions at 600 degrees C and 750 degrees C for the dry reforming of methane (DRM). However, about 33% carbon-whiskers (at 600 degrees C) and less than 1% carbon (at 750 degrees C) was deposited after 4 h of DRM. Adding up to 7.5 V% O-2 during the partial oxidation of methane (POM), and during the oxidative dry reforming of methane (ODRM), increased the CH4 conversion. At least 7.5% O-2 was required for carbon-free ODRM operation (carbon < 1%) even at a reaction temperature of 600 degrees C. Furthermore, the CH4 conversion increased from 44 to 52% at 600 degrees C, and from 85 to 88% at 750 degrees C. A H-2/CO ratio of 0.82 (at 600 degrees C) and 0.72 (at 750 degrees C) was also achieved. Increasing the O-2 amount also decreased the net CO2 conversion and both carbon-types in the spent catalyst. Unexpectedly, the fraction of metallic nickel sites decreased in the spent catalyst after ODRM though the conversions increased. Thus, syngas is produced with insignificant amounts of carbon at 600 degrees C and 750 degrees C by DRM using small amounts of oxygen.

Automated summary

The study found that adding oxygen during the dry reforming of methane can enhance CH4 conversion and reduce carbon deposition, leading to the production of syngas with insignificant amounts of carbon.