Power to Synthetic-Natural-Gas (SNG) technology consists of two main steps: water electrolysis and methanation; the primary energy input is usually surplus power from renewable energy sources, while the electrolytic hydrogen and carbon oxides from different CO_x sources are converted into methane that can be fed in the natural gas grid. We focus on methanation technology, where the main criteria are the complexity of process setup and reactor sizes to achieve production and SNG quality for gas-grid injection. The processes are simulated using a plug-flow model for the reactors and a pseudo-homogeneous kinetic law describing the reaction of CO₂ (that is rate limiting). The results show that feeding biogas or syngas (instead of CO₂) for methanation has remarkable effects regarding the operation and design of the processes; it is concluded that Power-to-SNG technologies that use methane rich streams are favorable in terms of biogas upgrading, H₂ requirements, reactor volumes and process simplicity, as far as these resources are available: e.g., using a typical composition (60% CH₄) the required inputs are 0.96 kmol of biogas, 1.54 kmol of H₂ and 0.26 m³ of reactors (two adiabatic beds with recirculation, R/F = 0.695) per kmol/min of pipeline quality dry gas product (95% CH₄), which means 60% hydrogen saving, less than 26% reaction volumes and near 62% reduction of process throughput, when compared to the methanation process that uses pure CO₂; conversion of syngas can be also favorable, but it requires high recirculation due to the large proportions of CO_x; e.g. for syngas (47.3%H₂-25.9%CO-17.2%CO₂-9.6%CH₄), the required values mean a 53% hydrogen saving and less than 25% reaction volumes, but only 11% reduction of process throughput.

合成天然气发电（SNG）技术包括两个主要步骤：水电解和甲烷化；一次能源输入通常是来自可再生能源的过剩电力，而来自不同CO _x来源的电解氢和碳氧化物则转化为甲烷，可以供入天然气网格。我们专注于甲烷化技术，其中主要标准是过程设置的复杂性和反应器尺寸，以实现气网注入的生产质量和SNG质量。使用反应器的塞流模型和描述CO ₂反应（即速率限制）的拟均相动力学定律对过程进行模拟。结果表明，饲喂沼气或合成气（而不是CO ₂）甲烷化对工艺的操作和设计有显着影响；结论是，只要有这些资源，就可以利用沼气的提质，利用H ₂要求，反应器体积和工艺简化等方面，使用富含甲烷的气的Power-to-SNG技术是有利的：例如，使用典型的成分（60％ CH ₄）所需的投入是每公里/分钟管道质量干气产品（95％CH ）的0.96 kmol的沼气，1.54 kmol的H ₂和0.26 m ³的反应器（两个带循环的绝热床，R / F = 0.695）。₄），这意味着与使用纯CO ₂的甲烷化工艺相比，可节省60％的氢气，不到26％的反应体积和近62％的工艺产量降低；合成气的转化也可能是有利的，但由于CO _x的比例很高，因此需要高再循环率。例如，对于合成气（47.3％H ₂ -25.9％CO-17.2％CO ₂ -9.6％CH ₄），所需值意味着节省53％的氢气和少于25％的反应体积，但仅减少11％的工艺产量。