Zeyan Pan, Zhuangzhuang Liu, Xiaona Hu et al.

Bioresources and Bioprocessing • 2023

Abstract Microbial electrosynthesis (MES) is a promising technology for CO 2 fixation and electrical energy storage. Currently, the low current density of MES limits its practical application. The H 2 -mediated and non-biofilm-driven MES could work under higher current density, but it is difficult to achieve high coulombic efficiency (CE) due to low H 2 solubility and poor mass transfer. Here, we proposed to enhance the hydrogen mass transfer by adding silica nanoparticles to the reactor. At pH 7, 35 ℃ and 39 A·m − 2 current density, with the addition of 0.3wt% silica nanoparticles, the volumetric mass transfer coefficient ( k La ) of H 2 in the reactor increased by 32.4% (from 0.37 h − 1 to 0.49 h − 1 ), thereby increasing the acetate production rate and CE of the reactor by 69.8% and 69.2%, respectively. The titer of acetate in the reactor with silica nanoparticles (18.5 g·L − 1 ) was 56.9% higher than that of the reactor without silica nanoparticles (11.8 g·L − 1 ). Moreover, the average acetate production rate of the reactor with silica nanoparticles was up to 2.14 g·L − 1 ·d − 1 in the stable increment phase, which was much higher than the other reported reactors. These results demonstrated that the addition of silica nanoparticles is an effective approach to enhancing the performance of H 2 -mediated MES reactors. Graphical Abstract

Zhiyuan Chen, Asier Grijalvo Rodriguez, Pello Nunez et al.

Catalysis Communications • 2022

Tubular water splitting electrolyzer was adapted to neutral pH conditions for the in-situ H2 supplying microbial electrosynthesis design. The electrolyzer was optimized to reduce ohmic losses and provide adequate gas separation. Direct membrane deposition was applied on a thin anionic exchange membrane for the membrane-electrode-assembly fabrication. Although the membrane resistance increased with the increasing membrane thickness from 55 to 165 μm, the contact resistance was reduced by applying stronger compression pressure on the membrane-electrode interface. A durability test was run for 120 h, showing a voltage increase of 134 μV/h. Moreover, the hydrogen permeability coefficient was determined at 10−14 mol/(mˑsˑPa).

Yujing Jiang, Shihao Tian, Hanyu Li et al.

The Innovation Materials • 2023

Konstantina‐Roxani Chatzipanagiotou, Virangni Soekhoe, Ludovic Jourdin et al.

ChemPlusChem • 2021

Electrocatalytic metals and microorganisms can be combined for CO 2 conversion in microbial electrosynthesis (MES). However, a systematic investigation on the nature of interactions between metals and MES is still lacking. To investigate this nature, we integrated a copper electrocatalyst, converting CO 2 to formate, with microorganisms, converting CO 2 to acetate. A co-catalytic (i. e. metabolic) relationship was evident, as up to 140 mg L -1 of formate was produced solely by copper oxide, while formate was also evidently produced by copper and consumed by microorganisms producing acetate. Due to non-metabolic interactions, current density decreased by over 4 times, though acetate yield increased by 3.3 times. Despite the antimicrobial role of copper, biofilm formation was possible on a pure copper surface. Overall, we show for the first time that a CO 2 -reducing copper electrocatalyst can be combined with MES under biological conditions, resulting in metabolic and non-metabolic interactions.

Zaiqiang Wu, Junsong Wang, Xueli Zhang et al.

Biochemical Engineering Journal • 2019

Vasan Sivalingam, Dietmar Winkler, Tone Haugen et al.

Bioresource Technology • 2022

Md Tabish Noori, Minji Park, Booki Min

Bioresource Technology • 2024

Shuwei Li, Min‐Soo Kim, Jungho Jae et al.

Bioresource Technology • 2022

Paniz Izadi, Jean‐Marie Fontmorin, Swee Su Lim et al.

Faraday Discussions • 2021

Technologies able to convert CO2 to various feedstocks for fuels and chemicals are emerging due to the urge of reducing greenhouse gas emissions and de-fossilizing chemical production. Microbial electrosynthesis (MES) has been shown a promising technique to synthesize organic products particularly acetate using microorganisms and electrons. However, the efficiency of the system is low. In this study, we demonstrated the simple yet efficient strategy in enhancing the efficiency of MES by applying continuous feeding regime. Compared to the fed-batch system, continuous operational mode provided better control of pH and constant medium refreshment, resulting in higher acetate production rate and more diverse bio-products, when the cathodic potential of -1.0 V Ag/AgCl and dissolved CO2 were provided. It was observed that hydraulic retention time (HRT) had a direct effect on the pattern of production, acetate production rate and coulombic efficiency. At HRT of 3 days, pH was around 5.2 and acetate was the dominant product with the highest production rate of 651.8 ± 214.2 ppm per day and a significant coulombic efficiency of 90%. However at the HRT of 7 days, pH was lower at around 4.5, and lower but stable acetate production rate of 280 ppm per day and a maximum coulombic efficiency of 80% was obtained. In addition, more diverse and longer chain products, such as butyrate, isovalerate and caproate, were detected with low concentrations only at the HRT of 7 days. Although microbial community analysis showed the change in the planktonic cells communities after switching the fed-batch mode to continuous feeding regime, Acetobacterium still remained as the responsible bacteria for CO2 reduction to acetate, dominating the cathodic biofilm.

Vasan Sivalingam, Carlos Dinamarca, Gamunu Samarakoon et al.

Sustainability • 2020

Biogas upgrading to biomethane with microbial electrosynthesis (MES) is receiving much attention due to increasing biomethane demands and surplus renewable energy. Research has demonstrated the feasibility of MES to increase methane yield by reducing CO2 in anaerobic digestion (AD). Such CO2 reduction occurs at the cathode and requires the supply of both protons and electrons. The most studied sources of protons and electrons are oxidation of organic substances and water, generated at the anode. These anodic reactions, however, also imply the production of CO2 and O2, respectively, both with negative implications for the AD process. A source of protons and electrons without CO2 and O2 as by-products would be beneficial for MES-enhanced biomethane production. This opinion article discusses the possibility of ammonium to serve as a sustainable proton and electron source.

Manal Alqahtani, Suman Bajracharya, Krishna P. Katuri et al.

The Science of The Total Environment • 2020

Bin Bian, Yogesh B. Singh, Korneel Rabaey et al.

Chemical Engineering Journal • 2022

Zhenyu Qiu, Kang Zhang, Xiang Ling Li et al.

Biochemical Engineering Journal • 2023

Kai Cui, Kun Guo, José M. Carvajal‐Arroyo et al.

Chemical Engineering Journal • 2023

Haifeng Huang, Qiong Huang, Tian‐shun Song et al.

Energy & Fuels • 2020

Microbial electrosynthesis (MES) is an electrochemical reduction technique where microorganisms attached to electrodes are used as catalysts for CO2 reduction into chemicals. In situ grown molybdenum carbide (Mo2C) without binder-modified electrodes for MES was constructed in different layer numbers. Results showed that the hydrogen evolution reaction activity of carbon felt (CF) with Mo2C was higher than that of bare CF. The volumetric acetate production rate of MES with in situ grown Mo2C through a single electrostatic self-assembly method was 0.15 ± 0.01 g L–1 day–1, which was 1.8 times that of the control. The final acetate concentration reached 4.56 ± 0.1 g L–1 within 30 days, and the coulomb efficiency was 50 ± 0.3%. In addition, scanning electron microscopy and microbial community analyses showed that Mo2C with a single layer was conducive to the attachment of microorganisms, improved the enrichment of Acetobacterium and Arcobacter, and inhibited the abundance of Sulfurospirillum. In situ grown Mo2C-modified cathode is an effective strategy for improving MES efficiency.

Clifford S. Morrison, Elizabeth Heitmann, William B. Armiger et al.

Advances in applied microbiology • 2018

Alexander Langsdorf, Julian Philipp Schütz, Roland Ulber et al.

Journal of CO2 Utilization • 2024

The aim of this work was to produce the biopolymer polyhydroxybutyrate (PHB) from industrial flue gas as CO2 source and electrolysis originating hydrogen via microbial electrosynthesis. Besides the laboratory experiments, the experiments were carried out under industrial conditions directly on-site in a cogeneration plant. We were able to demonstrate that the use of flue gas as a CO2 source has no detectable negative effect on bacterial growth and PHB production in comparison to a pure gas mixture. In an electrochemical H-cell 333 ± 44 mg L−1 PHB were obtained, which corresponds to a PHB content of 43 ± 3 % of the cell dry weight. By using flue gas for the production of the biopolymer PHB, not only CO2 emissions are reduced, but also possible environmental pollution from non-biodegradable plastics. To the best of our knowledge, this is the first time that the production of PHB from flue gas has been demonstrated using Cupriavidus necator.

Jörg S. Deutzmann, Alfred M. Spormann

Bioresource Technology Reports • 2023

Karthikeyan Rengasamy, Tahina Onina Ranaivoarisoa, Wei Bai et al.

Nanotechnology • 2020

Microbial electrosynthesis (MES) is an emerging technology that can convert carbon dioxide (CO 2 ) into value-added organic carbon compounds using electrons supplied from a cathode. However, MES is affected by low product formation due to limited extracellular electron uptake by microbes. Herein, a novel cathode was developed from chemically synthesized magnetite nanoparticles and reduced graphene oxide nanocomposite (rGO-MNPs). This nanocomposite was electrochemically deposited on carbon felt (CF/rGO-MNPs), and the modified material was used as a cathode for MES production. The bioplastic, polyhydroxybutyrate (PHB) produced by Rhodopseudomonas palustris TIE-1 (TIE-1), was measured from reactors with modified and unmodified cathodes. Results demonstrate that the magnetite nanoparticle anchored graphene cathode (CF/rGO-MNPs) exhibited higher PHB production (91.31 ± 0.9 mg l -1 ). This is ∼4.2 times higher than unmodified carbon felt (CF), and 20 times higher than previously reported using graphite. This modified cathode enhanced electron uptake to -11.7 ± 0.1 μA cm -2 , ∼5 times higher than CF cathode (-2.3 ± 0.08 μA cm -2 ). The faradaic efficiency of the modified cathode was ∼2 times higher than the unmodified cathode. Electrochemical analysis and scanning electron microscopy suggest that rGO-MNPs facilitated electron uptake and improved PHB production by TIE-1. Overall, the nanocomposite (rGO-MNPs) cathode modification enhances MES efficiency.

Tobechi Okoroafor, Sue Haile, Sharon B. Velasquez‐Orta

Journal of Hazardous Toxic and Radioactive Waste • 2020

Microbial electrosynthesis (MES) uses microbes and electricity to convert CO2 to high-grade chemicals alleviating greenhouse gas (GHG) emissions. Little is known on the environmental loads associated with the scale-up of the technology. Initially, the MES environmental impacts of synthesizing acetic, formic, or propionic acids, methanol, or ethanol were assessed using GaBi LCA software, and electricity produced 60% from fossil fuels. The results show that formic acid production had the lowest environmental impact in all eco-indicators due to the comparatively low energy requirements of its reactor and rectification unit. Second, three different formic acid production methods were compared with MES. Hydrolysis of methyl formate, the main conventional method was shown to be less environmentally harmful than the other three CO2 utilizing technologies analyzed when the electricity used was generated from fossil fuels except for the impact on climate change. Producing electricity from renewable sources (hydro, biogas, wind, and photovoltaic) made MES able to mitigate climate change with the lowest negative impact on the environment compared with others. Synthesis of products through MES using wind generated electricity could provide considerable benefits and should be considered when MES is industrially applied.

Bin Bian, Najiaowa Yu, Amir Akbari et al.

Water Research • 2024

Ping Wu, Jie Zhang, Jing Li et al.

The Science of The Total Environment • 2022

Khurram Tahir, Abdul Ali, Ahsan Abdul Ghani et al.

Chemosphere • 2023

Yuru Wang, Shuanglan Cheng, Cristiano Varrone et al.

Chemical Engineering Journal • 2024

Yonghang Zhou, Haifeng Huang, Haoqi Wang et al.

International Journal of Hydrogen Energy • 2021

Guan Wang, Yuechao Yao, Kai Tang et al.

Bioresource Technology • 2021

Microbial electrosynthesis of hydrogen peroxide is receiving growing interest for a green substitute for anthraquinone process.However, poor oxygen transmission of electrode remains an obstacle to enhance H 2 O 2 production rate without aeration. Here, a superhydrophobic natural air diffusion floating electrode (NADFE), which naturally and efficiently entraps O 2 in the air, was proposed for the first time to improve microbial electrosynthesis of H 2 O 2 . Furthermore, a one-step calcined electrode preparation method was developed to reduce energy consumption further. In the microbial electrolysis cell with the NADFE, a high H 2 O 2 production rate of 39 mg/L/h and current efficiency of 86% were achieved without aeration. The production rate of H 2 O 2 was 2.2 times that of a gas diffusion electrode. Importantly, the energy consumption was 34.3 times lower than an electrochemical system. Therefore, the high H 2 O 2 production rate and current efficiency, and low energy consumption of the process provide a superior alternative for environmental remediation.

Paolo Dessì, Claribel Buenaño-Vargas, Santiago Martínez-Sosa et al.

Environmental Science and Ecotechnology • 2023

The industrial adoption of microbial electrosynthesis (MES) is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs. In this study, a mixed microbial consortium originating from an anaerobic digester operated under saline conditions (∼13 g L -1 NaCl) was adapted for acetate production from bicarbonate in galvanostatic (0.25 mA cm -2 ) H-type cells at 5, 10, 15, or 20 g L -1 NaCl concentration. The acetogenic communities were successfully enriched only at 5 and 10 g L -1 NaCl, revealing an inhibitory threshold of about 6 g L -1 Na + . The enriched planktonic communities were then used as inoculum for 3D printed, three-chamber cells equipped with a gas diffusion biocathode. The cells were fed with CO 2 gas and operated galvanostatically (0.25 or 1.00 mA cm -2 ). The highest production rate of 55.4 g m -2 d -1 (0.89 g L -1 d -1 ), with 82.4% Coulombic efficiency, was obtained at 5 g L -1 NaCl concentration and 1 mA cm -2 applied current, achieving an average acetate production of 44.7 kg MWh -1 . Scanning electron microscopy and 16S rRNA sequencing analysis confirmed the formation of a cathodic biofilm dominated by Acetobacterium sp. Finally, three 3D printed cells were hydraulically connected in series to simulate an MES stack, achieving three-fold production rates than with the single cell at 0.25 mA cm -2 . This confirms that three-chamber MES cells are an efficient and scalable technology for CO 2 bio-electro recycling to acetate and that moderate saline conditions (5 g L -1 NaCl) can help reduce their power demand while preserving the activity of acetogens.

Tian‐shun Song, Guangrong Wang, Haoqi Wang et al.

Bioresources and Bioprocessing • 2019

Microbial electrosynthesis (MES) is potentially useful for the biological conversion of carbon dioxide into value-added chemicals and biofuels. The study evaluated several limiting factors that affect MES performance. Among all these factors, the optimization of the applied cell voltage, electrode spacing, and trace elements in catholytes may significantly improve the MES performance. MES was operated under the optimal condition with an applied cell voltage of 3 V, an electrode spacing of 8 cm, 2× salt solution, and 8× trace element of catholyte for 100 days, and the maximum acetate concentration reached 7.8 g L−1. The microbial community analyses of the cathode chamber over time showed that Acetobacterium, Enterobacteriaceae, Arcobacter, Sulfurospirillum, and Thioclava were the predominant genera during the entire MES process. The abundance of Acetobacterium first increased and then decreased, which was consistent with that of acetate production. These results provided useful hints for replacing the potentiostatic control of the cathodes in the future construction and operation of MES. Such results might also contribute to the practical operation of MES in large-scale systems.

Qing Li, Qian Fu, Hajime Kobayashi et al.

Sustainable Energy & Fuels • 2020

A GO/PEDOT film effectively enhances methanogenic biofilm formation and promotes the CH 4 producing performance of biocathodes.

Carolina Cruz Viggi, Sara Colantoni, F. Falzetti et al.

Fuel Cells • 2020

Abstract Microbial electrosynthesis (MES) is an emerging technology which exploits microbial cells to convert CO 2 into fuels, and value‐added chemicals using electrons supplied by a solid‐state cathode. Methane and acetic acid are typically the main CO 2 ‐reduction products attained in microbial electrosynthesis studies, although the production of other more valuable products has also been reported. So far, however, practical strategies to manipulate and steer the distribution of CO 2 reduction products during microbial electrosynthesis, particularly when mixed microbial cultures are employed as catalysts, are lacking. To specifically address this issue, here we investigated the influence of magnetite nanoparticles (NPs) supplementation (to a final concentration of 300 mg Fe L −1 ) on the microbial electrosynthesis process. Results demonstrated, that cells supplemented with magnetite NPs, exhibited a substantially higher yield of acetate production relative to unamended controls (up to 8.5 times higher, during the run with the cathode set at a potential of −700 mV vs . SHE, with a corresponding cathode capture efficiency of 17%) and, correspondingly, a lower yield of methane production (52% in the magnetite‐supplemented cell vs . 74% in the unamended control cell). Abiotic experiments indicated that the observed effects derived from magnetite catalyzing the biotic and abiotic hydrogen evolution reaction.

Guangrong Wang, Qiong Huang, Tian‐shun Song et al.

Energy & Fuels • 2020

Microbial electrosynthesis (MES) is an emerging technology through which autotrophic microorganisms can directly uptake electrons or indirectly uptake electrons through H2 in the cathode for reducing CO2 to chemicals. In this study, the performance of MES with engineered Clostridium ljungdahlii was improved by electrochemically depositing a nickel phosphide (Ni–P) catalyst on the cathode. The acetate production rate of MES with 15 cycles was 0.17 g L–1 day–1, which was 1.7 times higher than that of MES without the catalyst. The corresponding butyrate production rate was remarkably enhanced at 0.1 g L–1 day–1, which was 2.5 times higher than that of MES without the catalyst. Electrochemical studies, scanning electron microscopy, and confocal scanning laser microscopy showed that Ni–P could accelerate the release of hydrogen and promote biofilm formation. These results also implied that more H2 evolution could provide more reducing power for butyrate production in the presence of Ni–P. This study attempted to provide effective strategies for the accumulation of C4 products in MES.

Yitong Qian, Liping Huang, Peng Zhou et al.

The Science of The Total Environment • 2019

Vasan Sivalingam, Vafa Ahmadi, Babafemi Omodara et al.

Catalysts • 2020

This study presents a series of experiments to test the integration of syngas fermentation into a single-cell microbial electrosynthesis (MES) process. Minimal gas–liquid mass transfer is the primary bottleneck in such gas-fermentation processes. Therefore, we hypothesized that MES integration could trigger the thermodynamic barrier, resulting in higher gas–liquid mass transfer and product-formation rates. The study was performed in three different phases as batch experiments. The first phase dealt with mixed-culture fermentation at 1 bar H2 headspace pressure. During the second phase, surface electrodes were integrated into the fermentation medium, and investigations were performed in open-circuit mode. In the third phase, the electrodes were poised with a voltage, and the second phase was extended in closed-circuit mode. Phase 2 demonstrated three times the gas consumption (1021 mmol) and 63% more production of acetic acid (60 mmol/L) than Phase 1. However, Phase 3 failed; at –0.8 V, acetic acid was oxidized to yield hydrogen gas in the headspace.

Emmanuel Onyekachi Nwanebu, Sasha Omanovic, Sabahudin Hrapovic et al.

International Journal of Hydrogen Energy • 2021

Xia Hou, Liping Huang, Peng Zhou et al.

Journal of Hazardous Materials • 2019

Sovik Das, MM Ghangrekar

• 2017

Sovik Das, Indrajit Chakraborty, Swati Das et al.

Sustainable Energy Technologies and Assessments • 2020

Khurram Tahir, Abdul Ali, Jinseob Kim et al.

Chemosphere • 2023

Md Tabish Noori, S. Venkata Mohan, Booki Min

Sustainable Energy Technologies and Assessments • 2021

Qian Fu, Yuting He, Zhuo Li et al.

Energy Conversion and Management • 2022