A hybrid electro-thermochemical device for methane production from the air
Yao‐Wei Huang, Da Xu, Shuai Deng, Meng Lin
Abstract
Coupling direct air capture (DAC) with methane (CH4) production is a potential strategy for fuel production from the air. Here, we report a hybrid electro-thermochemical device for direct CH4 production from air. The proposed device features the cogeneration of carbon dioxide (CO2) and hydrogen (H2) in a single compartment via a bipolar membrane electrodialysis module, avoiding a separate water electrolyzer, followed by a thermochemical methanation reaction to produce CH4. H2-induced disturbances lead to efficient CO2 extraction without pumping requirement. The energy consumption and techno-economic analysis predict an energy reduction of 37.8% for DAC and a cost reduction of 36.6% compared with the decoupled route, respectively. Accordingly, CH4 cost is reduced by 12.6%. Our proof-of-concept experiments show that the energy consumption for CO2 release and H2 production is 704.0 kJ mol−1 and 967.4 kJ mol−1, respectively with subsequent methanation achieving a 97.3% conversion of CO2 and a CH4 production energy of 5206.4 kJ mol−1 showing a promising pathway for fuel processing from the air. Direct capture and conversion of CO2 from the atmosphere is appealing to realize negative emissions but challenging due to the inherent low CO2 concentration. Here, authors report a proof-of-concept hybrid electro-thermochemical device for direct CH4 production from the air.