Bioelectrochemical and Anaerobic Pathways for Microbial Energy Recovery: Progress, Performance Metrics, and Deployment Challenges

Abstract

Microbial energy technologies convert organic matter and carbon dioxide into useful energy carriers by exploiting microbial metabolism and electron-transfer networks. This review compares four representative platforms—anaerobic digestion (AD), microbial fuel cells (MFCs), microbial electrolysis cells (MECs), and microbial electrosynthesis (MES)—using a unified lens of biochemical pathways, reactor/electrode design, microbial ecology, and scalability. We highlight how extracellular electron transfer (EET), biofilm structure, and electrode surface chemistry govern bioelectrochemical performance, while syntrophic consortia and retention time control AD conversion. Recent advances in omics-enabled community management, non-precious cathode catalysts, and structured/3D electrodes have improved efficiency and robustness, yet major barriers remain: internal resistance, membrane fouling, product selectivity, and scale-up losses. We close by outlining practical integration routes with wastewater treatment and carbon-management infrastructure, clarifying where each technology is best positioned—from mature centralized biogas to decentralized treatment-power co-benefits, renewable hydrogen coupling, and carbon-to-chemicals conversion.