Microbial electrolysis cells for electromethanogenesis: Materials, configurations and operations

Anaerobic digestion is a traditional method of producing methane-containing biogas by utilizing the methanogenic conversion of organic matter like agricultural waste and animal excreta. Recently, the application of microbial electrolysis cell (MECs) technology to a traditional anaerobic digestion system has been extensively studied to find new opportunities in increasing wastewater treatability and methane yield and producing valuable chemicals. The finding that both anodic and cathodic bacteria can synthesize methane has led to the efforts of optimizing multiple aspects like microbial species, formation of biofilms, substrate sources and electrode surface for higher production of the combustible compound. MECs are very fascinating because of its ability to uptake a wide variety of raw materials including untreated wastewater (and its microbial content as biocatalysts). Extensive work in this field has established different systems of MECs for hydrogen production and biodegradation of organic compounds. This review is dedicated to explaining the operating principles and mechanism of the MECs for electromethanogenesis using different biochemical pathways. Emphasis on single- and double-chambered MECs along with reactor components is provided for a comprehensive description of the technology. Methane production using hydrogen evolution reaction and nanocatalysts has also been discussed.

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Sustainable Syntheses and Sources of Nanomaterials for Microbial Fuel/Electrolysis Cell Applications: An Overview of Recent Progress

Processes ◽

10.3390/pr9071221 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1221

Author(s):

Domenico Frattini ◽

Gopalu Karunakaran ◽

Eun-Bum Cho ◽

Yongchai Kwon

Keyword(s):

Microbial Fuel Cells ◽

Noble Metals ◽

Raw Materials ◽

Nanoparticle Synthesis ◽

Economic Feasibility ◽

Electrolysis Cell ◽

Microbial Electrolysis Cells ◽

Electrolysis Cells ◽

Bioenergy Generation ◽

Valuable Compounds

The use of microbial fuel cells (MFCs) is quickly spreading in the fields of bioenergy generation and wastewater treatment, as well as in the biosynthesis of valuable compounds for microbial electrolysis cells (MECs). MFCs and MECs have not been able to penetrate the market as economic feasibility is lost when their performances are boosted by nanomaterials. The nanoparticles used to realize or decorate the components (electrodes or the membrane) have expensive processing, purification, and raw resource costs. In recent decades, many studies have approached the problem of finding green synthesis routes and cheap sources for the most common nanoparticles employed in MFCs and MECs. These nanoparticles are essentially made of carbon, noble metals, and non-noble metals, together with a few other few doping elements. In this review, the most recent findings regarding the sustainable preparation of nanoparticles, in terms of syntheses and sources, are collected, commented, and proposed for applications in MFC and MEC devices. The use of naturally occurring, recycled, and alternative raw materials for nanoparticle synthesis is showcased in detail here. Several examples of how these naturally derived or sustainable nanoparticles have been employed in microbial devices are also examined. The results demonstrate that this approach is valuable and could represent a solid alternative to the expensive use of commercial nanoparticles.

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Enhancement of methane production from waste activated sludge using hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) process-A review

Bioresource Technology ◽

10.1016/j.biortech.2021.126641 ◽

2021 ◽

pp. 126641

Author(s):

Xue-Ting Wang ◽

Yi-Feng Zhang ◽

Bo Wang ◽

Song Wang ◽

Xue Xing ◽

...

Keyword(s):

Anaerobic Digestion ◽

Activated Sludge ◽

Methane Production ◽

Waste Activated Sludge ◽

Microbial Electrolysis Cells ◽

Electrolysis Cells ◽

Microbial Electrolysis

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Performance of microbial electrolysis cells with bioanodes grown at different external resistances

Water Science & Technology ◽

10.2166/wst.2015.418 ◽

2015 ◽

Vol 73 (5) ◽

pp. 1129-1135 ◽

Cited By ~ 7

Author(s):

Laura Rago ◽

Nuria Monpart ◽

Pilar Cortés ◽

Juan A. Baeza ◽

Albert Guisasola

Keyword(s):

H2 Production ◽

Current Intensity ◽

Electrolysis Cell ◽

Operational Parameters ◽

External Resistance ◽

Microbial Electrolysis Cells ◽

Start Up ◽

Electrolysis Cells ◽

Microbial Electrolysis

Bioelectrochemical systems need an anode with a high abundance of exoelectrogenic bacteria for an optimal performance. Among all possible operational parameters for an efficient enrichment, the role of external resistance in microbial fuel cell (MFC) has gained a lot of interest since it indirectly poises an anode potential, a key parameter for biofilm distribution and morphology. Thus, this work aims at investigating and discussing whether bioanodes selected at different external resistances under MFC operation present different responses under both MFC and microbial electrolysis cell (MEC) operation. A better MEC performance (i.e. shorter start-up time, higher current intensity and higher H2 production rate) was obtained with an anode from an MFC developed under low external resistance. Quantitative real-time polymerase chain reaction (qPCR) confirmed that a low external resistance provides an MFC anodic biofilm with the highest content of Geobacter because it allows higher current intensity, which is correlated to exoelectrogenic activity. High external resistances such as 1,000 Ω led to a slower start-up time under MEC operation.

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Anaerobic Digestion Enhancement With Microbial Electrolysis Cells

Handbook of Research on Microbial Tools for Environmental Waste Management - Advances in Environmental Engineering and Green Technologies ◽

10.4018/978-1-5225-3540-9.ch012 ◽

2018 ◽

pp. 259-269

Author(s):

Ellie Vipond ◽

Pattanathu K.S.M. Rahman

Keyword(s):

Anaerobic Digestion ◽

Downstream Processing ◽

Pilot Scale ◽

Industrial Biotechnology ◽

Purification Process ◽

Microbial Electrolysis Cells ◽

Electrolysis Cells ◽

Microbial Electrolysis ◽

Waste Degradation ◽

Processing Techniques

The engineering of replacements for crude oil is a priority within industrial biotechnology. Biogas, produced by anaerobic digestion (AD) during organic waste degradation, has been used for electricity generation and heating. Microbial electrolysis cells (MECs) are an emerging technology which when combined with AD can produce higher yields of such energy whilst simultaneously treating waste water and sludge. MECs are bioelectrochemical systems which utilize the metabolism of microbes to oxidize organics. The majority of the research has been focused on biohydrogen production, despite associated issues, which has resulted in poor commercialization prospects. Consequently, scientists are now suggesting that methane production should be the focus of MEC technology. This chapter presents lab research on the bioprocessing of biomethane using AD and MECs and addresses important issues, namely the lack of pilot-scale studies. Downstream processing techniques are discussed, as well as a novel suggestion of further utilising MECs in the purification process.

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Integration of microbial electrolysis cells with anaerobic digestion to treat beer industry wastewater

Integrated Microbial Fuel Cells for Wastewater Treatment ◽

10.1016/b978-0-12-817493-7.00015-1 ◽

2020 ◽

pp. 313-346 ◽

Cited By ~ 1

Author(s):

Thangavel Sangeetha ◽

Chellappan Praveen Rajneesh ◽

Wei-Mon Yan

Keyword(s):

Anaerobic Digestion ◽

Microbial Electrolysis Cells ◽

Beer Industry ◽

Electrolysis Cells ◽

Microbial Electrolysis ◽

Industry Wastewater

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Recent Developments in Microbial Electrolysis Cell-Based Biohydrogen Production Utilizing Wastewater as a Feedstock

Sustainability ◽

10.3390/su13168796 ◽

2021 ◽

Vol 13 (16) ◽

pp. 8796

Author(s):

Pooja Dange ◽

Soumya Pandit ◽

Dipak Jadhav ◽

Poojhaa Shanmugam ◽

Piyush Kumar Gupta ◽

...

Keyword(s):

Industrial Development ◽

Internal Resistance ◽

Hydrogen Gas ◽

Electrolysis Cell ◽

Hydrogen Yield ◽

Microbial Electrolysis Cell ◽

Microbial Electrolysis Cells ◽

Electrolysis Cells ◽

Carbon Neutral ◽

Microbial Electrolysis

Carbon constraints, as well as the growing hazard of greenhouse gas emissions, have accelerated research into all possible renewable energy and fuel sources. Microbial electrolysis cells (MECs), a novel technology able to convert soluble organic matter into energy such as hydrogen gas, represent the most recent breakthrough. While research into energy recovery from wastewater using microbial electrolysis cells is fascinating and a carbon-neutral technology that is still mostly limited to lab-scale applications, much more work on improving the function of microbial electrolysis cells would be required to expand their use in many of these applications. The present limiting issues for effective scaling up of the manufacturing process include the high manufacturing costs of microbial electrolysis cells, their high internal resistance and methanogenesis, and membrane/cathode biofouling. This paper examines the evolution of microbial electrolysis cell technology in terms of hydrogen yield, operational aspects that impact total hydrogen output in optimization studies, and important information on the efficiency of the processes. Moreover, life-cycle assessment of MEC technology in comparison to other technologies has been discussed. According to the results, MEC is at technology readiness level (TRL) 5, which means that it is ready for industrial development, and, according to the techno-economics, it may be commercialized soon due to its carbon-neutral qualities.

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