Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

Abstract

The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (> 0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment.

In situ Biofilm Quantification in Bioelectrochemical Systems by using Optical Coherence Tomography

“…In BESs, microorganisms catalyze the electrochemical formation or degradation of organic molecules by interfacing their biological metabolism with an electrode 1, 2, 3. The interaction between microorganisms and electrical conductive structures makes these systems unique and versatile, with potential applications in electrical energy storage,4, 5 energy‐ and nutrient‐recovering wastewater treatment systems,6, 7, 8 production of high‐value chemical commodities,9, 10 long‐term off‐grid low‐power electricity generation,11, 12 and the development of highly specific and innovative biosensors 13, 14. Additionally, microorganisms may provide temporal charge storage within the microbial cell 15, 16, 17.…”

Optimizing the electrode size and arrangement in a microbial electrolysis cell

“…Microbial electrolysis cells (MECs) are bioelectrochemical reactors producing hydrogen through microbially catalyzed electrolysis of organic matter (Logan et al, 2008). Since this process was first reported (Liu et al, 2005b;Rozendal et al, 2006), the MEC design has been constantly improving resulting in a substantial increase of the volumetric efficiency .…”

Hydrogen production in a microbial electrolysis cell with nickel-based gas diffusion cathodes

“…In this way, a higher hydrogen recovery can be obtained and at a much lower energy input than that used in water electrolysis. More importantly, biocatalyzed electrolysis enables the possibility of direct fuel production from a diverse range of waste streams [7][8][9]. Most microbial electrolysis cells (MFCs) are operated * Corresponding author.…”