Progress towards catalyzing electro-methanogenesis in anaerobic digestion process: Fundamentals, process optimization, design and scale-up considerations

• Published in: Bioresource technology 2019-10, Vol.289, p.121738-121738, Article 121738
• Main Authors: Zakaria, Basem S., Dhar, Bipro Ranjan
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Bio-methane; Electro-methanogenesis; Methanogens; Microbial electrolysis cells
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121738

[Display omitted] •Recent developments in electro-methanogenesis were critically reviewed.•Key bacterial and archaeal members and their functional roles were summarized.•Extrinsic parameters for process optimization and development were reviewed.•Research gaps were highlighted to provide directions for future development. Electro-methanogenesis represents an emerging bio-methane production pathway that can be achieved through integrating microbial electrolysis cell (MEC) with conventional anaerobic digester (AD). Since 2009, a significant number of publications have reported superior methane productivity and kinetics from MEC-AD integrated systems. The overall objective of this review is to communicate the recent advances towards promoting electro-methanogenesis in the anaerobic digestion process. Firstly, the electro-methanogenesis pathways and functional roles of key microbial members are summarized. Secondly, various extrinsic process parameters, such as applied voltage/potential, pH, and temperature are discussed with emphasis on process optimization. Moreover, available methods for the inoculation and start-up of MEC-AD process are critically reviewed. Finally, system design and scale-up considerations, such as the selection of electrode materials, surface area and surface chemistry of electrode materials, and electrode spacing are summarized.