Impact of impurities on biogas valorization through dry reforming of methane reaction

Biogas is mainly composed of methane, carbon dioxide as well as other compounds such as water and volatile organic compounds (VOCs). In this study, the composition of a biogas produced in a landfill is determined using gas chromatography. CH₄ and CO₂ represent 60% of its composition, rendering a valorization via the dry reforming of methane (DRM) reaction very promising. Moreover, H₂O and VOCs represent respectively 1.5% and 1500 ppm of biogas, which may affect the catalytic efficiency. The performance of CoNiMgAl catalysts derived from hydrotalcites is studied in the presence of toluene, water and a combination of both. The presence of toluene causes a progressive increase in the catalytic activity as well as higher carbon deposition. The addition of water decreases CO₂ conversion and carbon formation and increases the H₂/CO to values closer to 1. When both molecules are added, the catalytic activity remains stable, confirming that DRM is possible in the presence of both compounds.