scholarly journals Enhancing methane oxidation in a bioelectrochemical membrane reactor using a soluble electron mediator

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xueqin Zhang ◽  
Hesamoddin Rabiee ◽  
Joshua Frank ◽  
Chen Cai ◽  
Terra Stark ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Hollow Fibre ◽  
Extracellular Electron Transfer ◽  
Engineering Optimization ◽  
Direct Oxidation ◽  
Electron Mediator ◽  
Combined Use ◽  
Slow Kinetics ◽  
Soluble Mediator ◽  
Kinetics Of

Abstract Background Bioelectrochemical methane oxidation catalysed by anaerobic methanotrophic archaea (ANME) is constrained by limited methane bioavailability as well as by slow kinetics of extracellular electron transfer (EET) of ANME. In this study, we tested a combination of two strategies to improve the performance of methane-driven bioelectrochemical systems that includes (1) the use of hollow fibre membranes (HFMs) for efficient methane delivery to the ANME organisms and (2) the amendment of ferricyanide, an effective soluble redox mediator, to the liquid medium to enable electrochemical bridging between the ANME organisms and the anode, as well as to promote EET kinetics of ANME. Results The combined use of HFMs and the soluble mediator increased the performance of ANME-based bioelectrochemical methane oxidation, enabling the delivery of up to 196 mA m−2, thereby outperforming the control system by 244 times when HFMs were pressurized at 1.6 bar. Conclusions Improving methane delivery and EET are critical to enhance the performance of bioelectrochemical methane oxidation. This work demonstrates that by process engineering optimization, energy recovery from methane through its direct oxidation at relevant rates is feasible.

scholarly journals Slow Kinetics of Brownian Maxima

2014 ◽  
Vol 113 (3) ◽  
Author(s):  
E. Ben-Naim ◽  
P. L. Krapivsky
Keyword(s):  
Slow Kinetics ◽  
Kinetics Of

Direct Oxidation of Hydrocarbons in a Solid Oxide Fuel Cell: I. Methane Oxidation

1999 ◽  
Vol 146 (10) ◽  
pp. 3603-3605 ◽  
Author(s):  
Seungdoo Park ◽  
Radu Craciun ◽  
John M. Vohs ◽  
Raymond J. Gorte
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Methane Oxidation ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Direct Oxidation ◽  
Oxidation Of Hydrocarbons

scholarly journals Unusually sluggish microemulsion system with water, toluene and a technical branched alkyl polyethoxylate

2015 ◽  
Vol 21 (3) ◽  
pp. 429-439 ◽  
Author(s):  
Marija Ilic ◽  
Franz-Hubert Haegel ◽  
Vesna Pavelkic ◽  
Snezana Zlatanovic ◽  
Zoran Markovic ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Nonionic Surfactants ◽  
Binary Phase Diagram ◽  
Visual Observation ◽  
Ternary Mixtures ◽  
Microemulsion System ◽  
Slow Kinetics ◽  
Bicontinuous Microemulsion ◽  
Kinetics Of ◽  
Qualitative Measurements

Microemulsion systems with water, toluene and nonionic surfactants are interesting for application due to the excellent solvent properties of aromatic hydrocarbons. In this study, the pseudo-binary phase diagram (?fish-diagram?) of such a ternary system was investigated using a branched technical alkyl polyethoxylate. Lutensol ON 50 (i-C10E5) was considered a suitable surfactant. The system with technical branched i-C10E5 exhibits very long and for compositions near optimum solubilization, i.e. the minimum content of surfactant needed for a bicontinuous microemulsion, extremely long times for equilibration. In addition to visual observation, qualitative measurements of turbidity were performed with a UV-Vis spectrometer for characterizing the behavior of this unusually sluggish system. Isothermal phase diagrams at 20, 25 and 30?C yielded inconsistent results after the change of temperature and the application of mechanical stress for different treatment of the samples. Ternary mixtures of water, toluene, and Lutensol ON 50 seem to form long-living metastable states. The sluggishness and the ambiguous phase behavior of the system are discussed. Inconsistent results are attributed to the slow kinetics of the formation and destruction of liquid crystals and the ability of the system to form miniemulsions within an unusual concentration range.

Slow kinetics of a potassium channel inAcetabularia

1988 ◽  
Vol 102 (2) ◽  
pp. 141-152 ◽  
Author(s):  
A. Bertl ◽  
H. G. Klieber ◽  
D. Gradmann
Keyword(s):  
Potassium Channel ◽  
Slow Kinetics ◽  
Kinetics Of

Nitrogen doped porous carbon fiber/vertical graphene as efficient polysulfide conversion catalyst for high performance lithium sulfur batteries

2021 ◽  
Author(s):  
junsheng lin ◽  
Yangcheng Mo ◽  
Shiwen Li ◽  
Jie Yu
Keyword(s):  
High Performance ◽  
Practical Application ◽  
Nitrogen Doped ◽  
High Sulfur Content ◽  
Slow Kinetics ◽  
Lithium Sulfur Batteries ◽  
Conversion Catalyst ◽  
Kinetics Of ◽  
Lithium Sulfur ◽  
High Sulfur Loading

Under high sulfur loading, high sulfur content and low electrolyte/sulfur ratio (E/S), the practical application of lithium sulfur (Li–S) batteries is seriously limited by the negative and slow kinetics of...

scholarly journals Humin Assists Reductive Acetogenesis in Absence of Other External Electron Donor

2020 ◽  
Vol 17 (12) ◽  
pp. 4211 ◽  
Author(s):  
Mahasweta Laskar ◽  
Takuya Kasai ◽  
Takanori Awata ◽  
Arata Katayama
Keyword(s):  
Carbon Source ◽  
Electron Donor ◽  
16S Rrna Genes ◽  
Reductive Dehalogenation ◽  
Rrna Genes ◽  
Extracellular Electron Transfer ◽  
Metagenomic Sequencing ◽  
Electron Mediator ◽  
Total Electron ◽  
Methanogenic Activity

The utilization of extracellular electron transfer by microorganism is highly engaging for remediation of toxic pollutants under “energy-starved” conditions. Humin, an organo-mineral complex of soil, has been instrumental as an external electron mediator for suitable electron donors in the remediative works of reductive dehalogenation, denitrification, and so forth. Here, we report, for the first time, that humin assists microbial acetogenesis as the extracellular electron donor using the electron acceptor CO 2 . Humin was obtained from Kamajima paddy soil, Japan. The anaerobic acetogenic consortium in mineral medium containing CO 2 / HCO 3 − as the inorganic carbon source used suspended humin as the energy source under mesophilic dark conditions. Retardation of acetogenesis under the CO 2 -deficient conditions demonstrated that humin did not function as the organic carbon source but as electron donor in the CO 2 -reducing acetogenesis. The consortium with humin also achieved anaerobic dechlorination with limited methanogenic activity. Total electron-donating capacity of humin was estimated at about 87 µeeq/g-humin. The metagenomic sequencing of 16S rRNA genes showed the predominance of Firmicutes (71.8 ± 2.5%) in the consortium, and Lachnospiraceae and Ruminococcaceae were considered as the CO 2 -reducing acetogens in the consortium. Thus, microbial fixation of CO 2 using humin introduces new insight to the holistic approach for sustainable treatment of contaminants in environment.

scholarly journals Recent Advances in Nanostructured Transition Metal Carbide- and Nitride-Based Cathode Electrocatalysts for Li–O2 Batteries (LOBs): A Brief Review

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2106
Author(s):  
K. Karuppasamy ◽  
K. Prasanna ◽  
Vasanth Rajendiran Jothi ◽  
Dhanasekaran Vikraman ◽  
Sajjad Hussain ◽  
...  
Keyword(s):  
Transition Metal ◽  
Rational Design ◽  
Rate Capability ◽  
High Energy ◽  
High Energy Density ◽  
Electrochemical Kinetics ◽  
Transition Metal Carbide ◽  
Round Trip ◽  
Slow Kinetics ◽  
Kinetics Of

A large volume of research on lithium–oxygen (Li–O2) batteries (LOBs) has been conducted in the recent decades, inspired by their high energy density and power density. However, these future generation energy-storage devices are still subject to technical limitations, including a squat round-trip efficiency and a deprived rate-capability, due to the slow-moving electrochemical kinetics of both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) over the surface of the cathode catalyst. Because the electrochemistry of LOBs is rather complex, only a limited range of cathode catalysts has been employed in the past. To understand the catalytic mechanisms involved and improve overall cell performance, the development of new cathode electrocatalysts with enhanced round-trip efficiency is extremely important. In this context, transition metal carbides and nitrides (TMCs and TMNs, respectively) have been explored as potential catalysts to overcome the slow kinetics of electrochemical reactions. To provide an accessible and up-to-date summary for the research community, the present paper reviews the recent advancements of TMCs and TMNs and its applications as active electrocatalysts for LOBs. In particular, significant studies on the rational design of catalysts and the properties of TMC/TMN in LOBs are discussed, and the prospects and challenges facing the continued development of TMC/TMN electrocatalysts and strategies for attaining higher OER/ORR activity in LOBs are presented.

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