CO₂ hydrogenation to methane (CO₂ methanation) is gaining increasing interest as a major chemical synthesis process for chemical storage of fluctuating renewable energy and producing synthetic natural gas by providing an effective process for biogas upgrading. In this study, a series of 12 and 20 wt% Ni/Al₂O₃ catalysts, either unpromoted or promoted by 0.5 wt% Ru, were prepared by the incipient wetness method for the CO₂ methanation reaction from a feed of pure CO₂ or biogas. The catalysts were characterized by N₂ physisorption, XRD, TPR and H₂ chemisorption. The activity for the 12 wt% Ni catalyst increased continuously in the temperature range from 250 °C to 400 °C. Increasing the Ni loading and Ru promotion greatly improved the activity of the catalyst. At 350 °C, the highest CO₂ conversion of 82% and CH₄ selectivity of 100% was achieved over the 20Ni0.5Ru/Al₂O₃ catalyst. Thereafter, methanation of a simulated biogas mixture was investigated over the 20Ni/Al₂O₃ and 20Ni0.5Ru/Al₂O₃ catalysts. The results showed that the CO₂ conversion and CH₄ selectivity were only mildly affected by the feed composition. Furthermore, the stability of the catalysts was similar regardless of the feed composition. This study demonstrates that high purity CH₄ can be achieved from a biogas feed over our Ni based catalysts.

作为一种主要的化学合成方法，CO ₂加氢成甲烷（CO ₂甲烷化）是一种重要的化学合成方法，用于通过波动性可再生能源的化学存储和通过提供有效的沼气提纯工艺来生产合成天然气。在这项研究中，采用初湿法从纯CO ₂进料制备了一系列12种和20 wt％的Ni / Al ₂ O ₃催化剂，无论它们是未经促进还是由0.5 wt％Ru促进，都可以用于CO ₂甲烷化反应。或沼气。催化剂的特征在于N _2的物理吸附，XRD，TPR和H ₂化学吸附。12 wt％Ni催化剂的活性在250°C至400°C的温度范围内连续增加。Ni负载量的增加和Ru的促进大大提高了催化剂的活性。在350°C下，相对于20Ni0.5Ru / Al ₂ O ₃催化剂，最高的CO ₂转化率为82％，CH _4的选择性为100％。此后，在20Ni / Al ₂ O ₃和20Ni0.5Ru / Al ₂ O ₃催化剂上研究了模拟沼气混合物的甲烷化反应。结果表明，CO ₂转化率和CH ₄进料组成仅对选择性有轻微的影响。此外，催化剂的稳定性与进料组成无关。这项研究表明，在我们的镍基催化剂上通过沼气进料可以实现高纯度CH ₄。