Microbial electrochemical system is a promising CO2-to-CH4 conversion technology that can upgrade raw biogas to high calorific content for downstream applications. The development of efficient, robust, and cost-effective biocathode is the pivotal issue for its industrial application. In this study, intact anaerobic granular sludge (AGS), which was the conventional biocatalyst in anaerobic digestion processes for high-efficiency CH4 production, was for the first time employed as biocathode in electromethanogenesis system (EM) for biogas upgrading. The applied voltage (0, 3, 4, and 5 V) and biogas flow rate (5.22–23.43 mL/h) were modulated to optimize biogas upgrading performance in the AGS-EM system. The CH4 content in treated biogas could reach as high as 97.9 ± 2.3% at an applied voltage of 4 V and a gas flow rate of 17.79 mL/h. The system showed superior stability and anti-interference ability in the continuous operation mode for 2 months. 16S rRNA sequencing results showed that Methanobacterium and Azoarcus were the dominant populations in biocathode. The AGS-EM system obtained an energy benefit of 477.3 kJ/molbiogas, and economic benefit of 446.4 EUR/m3biogas. The novel AGS-EM system showed the promising perspectives for the industrial application in the field of biogas upgrading and renewable energy storage.
|Number of pages||9|
|Publication status||Published - 2020|
- Biogas upgrading
- Anaerobic granular sludge
- CO2 capture and storage
- Microbial electrochemical system
Zhou, H., Xing, D., Xu, M., Su, Y., & Zhang, Y. (2020). Biogas upgrading and energy storage via electromethanogenesis using intact anaerobic granular sludge as biocathode. Applied Energy, 269, .