Microbial Fuel Cells in Relation to Conventional Anaerobic Digestion Technology

TLDR

Conventional anaerobic digestion generates biogas for renewable energy but struggles at low temperatures and incurs high costs, whereas microbial fuel cells can treat low‑concentration substrates below 20 °C yet face investment, scaling, and performance limitations. The study proposes using microbial fuel cells as a new electricity‑producing bioconversion pathway and aims to improve their economic feasibility by optimizing reactor design, power density, and material costs. Microbial fuel cells outperform conventional anaerobic digestion for low‑concentration substrates below 20 °C and offer complementary application niches without directly competing with anaerobic digestion.

Abstract

Abstract Conventional anaerobic digestion based bioconversion processes produce biogas and have as such been widely applied for the production of renewable energy so far. An innovative technology, based on the use of microbial fuel cells, is considered as a new pathway for bioconversion processes towards electricity. In comparison with conventional anaerobic digestion, the microbial fuel cell technology holds some specific advantages, such as its applicability for the treatment of low concentration substrates at temperatures below 20 °C, where anaerobic digestion generally fails to function. This provides some specific application niches of the microbial fuel cell technology where it does not compete with but complements the anaerobic digestion technology. However, microbial fuel cells still face important limitations in terms of large‐scale application. The limitations involve the investment costs, upscale technical issues and the factors limiting the performance, both in terms of anodic and cathodic electron transfer. Research to render the microbial fuel cell technology more economically feasible and applicable should focus on reactor configuration, power density and the material costs.