This paper presents a hybrid electro-thermochemical device for direct methane (CH₄) production from air. The device integrates direct air capture (DAC) and hydrogen (H₂) production in a single bipolar membrane electrodialysis (BPMED) module, followed by a thermochemical methanation reaction. H₂ acts as a sweep gas, reducing energy consumption. Energy and techno-economic analyses show significant reductions compared to decoupled methods. Proof-of-concept experiments demonstrate high CO₂ conversion and CH₄ production.

Yaowei Huang, Da Xu, Shuai Deng, Meng Lin