To improve the energy‐to‐CH₄ efficiency and enhance renewable power utilization, we investigate direct Power‐to‐Methane at low inlet H₂ content (25 vol%) in solid oxide electrolysis cell (SOEC). The synergy of the pressurized operation and the electricity input effectively enhances CH₄ yield by one‐order of magnitude from 2.8% to 28.7% and the CO₂‐to‐CH₄ ratio from 4.4% to 39.5% in the H₂‐reduced case, where the ratio of H₂ consumption to total energy consumption decreases to 41% and the energy‐to‐CH₄ efficiency increases to 53%. We develop a multiphysics tubular SOEC model to understand the intrinsic coupling between electrochemistry and heterogeneous catalytic chemistry. From the perspective of performance enhancement, geometry optimization, and thermal design, inhibiting CH₄ production in the inlet gas‐controlled zone and promoting CH₄ production synergistically in both the electrochemistry‐controlled zone and the temperature‐controlled zone is the key to improve the energy‐to‐CH₄ efficiency.

中文翻译：

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加压管式固体氧化物H2O / CO2电解槽，可直接发电为甲烷

为了提高能量转化为CH _4的效率并提高可再生能源的利用率，我们研究了固体氧化物电解池（SOEC）中低入口H ₂含量（25％（体积））的直接甲烷转化。在减少H _2的情况下，加压操作和电力输入的协同作用可有效地将CH _4的产率从2.8％提高到28.7％，并且将CO ₂与CH _4的比例从4.4％提高到39.5％。，其中H ₂消耗量占总能量消耗的比例降低至41％，能量转化为CH ₄效率提高到53％。我们开发了一个多物理场管状SOEC模型，以了解电化学与非均相催化化学之间的内在耦合。从性能增强，几何优化，和热设计的角度来看，抑制CH ₄的生产在入口气体控制区和促进CH ₄协同生产在两个电化学控制区和温度控制区是提高的关键CH _4的能量效率。