Abstract Direct methanation of biogas converts the CO2 in raw-biogas to methane, enabling higher methane yield and an elelctricity storage option via Power-to-Gas. As the thermodynamic equilibrium limits the methane yield, unreacted hydrogen has to be removed and recycled to reach grid injection quality. We tested a commercial biogas upgrading membrane for hydrogen recycling at TRL 5. Based on the experiments, we developed a concept, which flexibly combines biogas upgrading and methanation post-upgrading in a single unit. This allows switching between the two operation modes, which can improve the economic benefit of the system. The hollow fibre membrane module was tested simulating the methanation product gas (biomethane, 12 % H2 in CH4) and biogas (40 % CO2 in CH4) in pressure ranges of 3 to 9 bar. In both cases, grid injection limitations (

中文翻译：

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沼气提质膜在电制甲烷过程中氢气循环的灵活应用

摘要 沼气的直接甲烷化将原始沼气中的 CO2 转化为甲烷，从而通过电转气实现更高的甲烷产量和电力存储选择。由于热力学平衡限制了甲烷产量，因此必须去除和回收未反应的氢气以达到网格注入质量。我们在 TRL 5 测试了用于氢回收的商用沼气升级膜。基于实验，我们开发了一个概念，将沼气升级和甲烷化后升级灵活地结合在一个单元中。这允许在两种操作模式之间切换，从而可以提高系统的经济效益。在 3 到 9 巴的压力范围内模拟甲烷化产物气体（生物甲烷，CH4 中含有 12% H2）和沼气（CH4 中含有 40% CO2）对中空纤维膜组件进行了测试。在这两种情况下，网格注入限制（