scholarly journals Faradaic efficiency in protonic-ceramic electrolysis cells

2021 ◽  
Author(s):  
Huayang Zhu ◽  
Sandrine Ricote ◽  
Robert J Kee
Keyword(s):  
Operating Conditions ◽  
Electrolysis Cell ◽  
Model Framework ◽  
Ideal Behavior ◽  
Faradaic Efficiency ◽  
External Power Source ◽  
A Cell ◽  
External Power ◽  
Mixed Ionic Electronic Conductors ◽  
Electron Holes

Abstract Proton-conducting ceramics (e.g., doped barium zirconates or cerates) are typically mixed ionic-electronic conductors (MIEC). The electronic conduction, typically in the form of positively charged small polarons or electron holes, leads to “electronic leakage.” In an ideal steam-electrolysis cell, one gas-phase H2 molecule is produced from every two electrons delivered from an external power source. In other words, such ideal behavior achieves 100% faradaic efficiency. However, the electronic flux associated with MIEC membranes contributes to reduced faradaic efficiency. The present paper develops a model that predicts the behavior of faradaic efficiency as a function of electrolysiscell operating conditions. Although the model framework is more general, the paper focuses on the behavior of a cell based upon a BaCe0.7Zr0.1Y0.1Yb0.1O3−δ (BCZYYb) membrane. The study predicts the effects of operating conditions, including temperature, pressure, and gas compositions.

scholarly journals Applied voltage optimization for denitrification process improvement by denitrifying species of Pseudomonas in microbial electrolysis cell (MEC)

2018 ◽  
Vol 67 ◽  
pp. 02027
Author(s):  
Putty Ekadewi ◽  
Matthew Hardhi ◽  
Putri Anggun Puspitarini ◽  
Hidayati Istiqomah ◽  
Cristina Gomez ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Removal Efficiency ◽  
Applied Voltage ◽  
Nitrate Removal ◽  
Electrolysis Cell ◽  
Microbial Electrolysis Cell ◽  
External Power Source ◽  
Pseudomonas Nitroreducens ◽  
External Power ◽  
Microbial Electrolysis

Denitrification is the conversion process of nitrate to gaseous nitrogen forms carried out by bacteria commonly referred to as denitrifiers. Microbial Electrolysis Cell (MEC) is a type of bioelectrochemical system (BES) that is connected to external power source to aid the reactions. This research investigates the effect of applied voltage value on denitrification by nitrate removal efficiency of two model denitrifying species from the genus Pseudomonas in single-chambered MEC. Pseudomonas aeruginosa and Pseudomonas nitroreducens exhibited native removal efficiency at 70.62% and 68.20%, respectively. These values respectively reached up to 89.67% and 88.58% at 1.20 V, the upper limit of this study. Pseudomonas aeruginosa displayed better performance in MEC based off its produced current stability (mA) across the 0.35-1.20 V range. The effect of applied voltage on nitrate removal efficiency and setup performance was more prominent on known exoelectrogenic species of Pseudomonas such as Pseudomonas aeruginosa compared to Pseudomonas nitroreducens. Operating applied voltages of 0.35 V and 0.70 V was recommended for the application of the system based on technical and economical considerations. Further studies are needed to determine the response of the bacteria on wider range of applied voltages in MEC as well as elucidating these effects on autotrophic systems.

scholarly journals H2-CO2 polymer electrolyte fuel cell that generates power while evolving CH4 at the Pt0.8Ru0.2/C cathode

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shofu Matsuda ◽  
Yuuki Niitsuma ◽  
Yuta Yoshida ◽  
Minoru Umeda
Keyword(s):  
Fuel Cell ◽  
Electric Power ◽  
Polymer Electrolyte ◽  
Carbon Capture ◽  
Polymer Electrolyte Fuel Cell ◽  
Cell Temperature ◽  
Faradaic Efficiency ◽  
Carbon Capture And Utilization ◽  
Electrode Potentials ◽  
A Cell

AbstractGenerating electric power using CO2 as a reactant is challenging because the electroreduction of CO2 usually requires a large overpotential. Herein, we report the design and development of a polymer electrolyte fuel cell driven by feeding H2 and CO2 to the anode (Pt/C) and cathode (Pt0.8Ru0.2/C), respectively, based on their theoretical electrode potentials. Pt–Ru/C is a promising electrocatalysts for CO2 reduction at a low overpotential; consequently, CH4 is continuously produced through CO2 reduction with an enhanced faradaic efficiency (18.2%) and without an overpotential (at 0.20 V vs. RHE) was achieved when dilute CO2 is fed at a cell temperature of 40 °C. Significantly, the cell generated electric power (0.14 mW cm−2) while simultaneously yielding CH4 at 86.3 μmol g−1 h−1. These results show that a H2-CO2 fuel cell is a promising technology for promoting the carbon capture and utilization (CCU) strategy.

scholarly journals Lifetime Prediction for a Cell-on-Board (COB) Light Source Based on the Adaptive Neuro-Fuzzy Inference System (ANFIS)

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
İsmail Kıyak ◽  
Gökhan Gökmen ◽  
Gökhan Koçyiğit
Keyword(s):  
Fuzzy Inference ◽  
Prediction Method ◽  
Operating Conditions ◽  
Lifetime Prediction ◽  
Statistical Characteristics ◽  
Ambient Conditions ◽  
Inference System ◽  
Initial Task ◽  
Neuro Fuzzy ◽  
A Cell

Predicting the lifetime of a LED lighting system is important for the implementation of design specifications and comparative analysis of the financial competition of various illuminating systems. Most lifetime information published by LED manufacturers and standardization organizations is limited to certain temperature and current values. However, as a result of different working and ambient conditions throughout the whole operating period, significant differences in lifetimes can be observed. In this article, an advanced method of lifetime prediction is proposed considering the initial task areas and the statistical characteristics of the study values obtained in the accelerated fragmentation test. This study proposes a new method to predict the lifetime of COB LED using an artificial intelligence approach and LM-80 data. Accordingly, a database with 6000 hours of LM-80 data was created using the Neuro-Fuzzy (ANFIS) algorithm, and a highly accurate lifetime prediction method was developed. This method reveals an approximate similarity of 99.8506% with the benchmark lifetime. The proposed methodology may provide a useful guideline to lifetime predictions of LED-related products which can also be adapted to different operating conditions in a shorter time compared to conventional methods. At the same time, this method can be used in the life prediction of nanosensors and can be produced with the 3D technique.

scholarly journals Performance Study of Split Ferrite Cores Designed for EMI Suppression on Cables

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1992
Author(s):  
Adrian Suarez ◽  
Jorge Victoria ◽  
Jose Torres ◽  
Pedro A. Martinez ◽  
Antonio Alcarria ◽  
...  
Keyword(s):  
Electromagnetic Compatibility ◽  
Electronic Device ◽  
Fem Simulation ◽  
Power Cables ◽  
Performance Study ◽  
External Power Source ◽  
External Power ◽  
Cable Assembly ◽  
Wired Communication

The ideal procedure to start designing an electronic device is to consider the electromagnetic compatibility (EMC) from the beginning. Even so, EMC problems can appear afterward, especially when the designed system is interconnected with external devices. Thereby, electromagnetic interferences (EMIs) could be transmitted to our device from power cables that interconnect it with an external power source or are connected to another system to establish wired communication. The application of an EMI suppressor such as a sleeve core that encircles the cables is a widely used technique to attenuate EM disturbances. This contribution is focused on the characterization of a variation of this cable filtering solution based on openable core clamp or snap ferrites. This component is manufactured by two split parts pressed together by a snap-on mechanism which turns this into a quick, easy to install solution for reducing post-cable assembly EMI problems. The performance of three different materials, including two polycrystalline (MnZn and NiZn) materials and nanocrystalline (NC) solution, are analyzed in terms of effectiveness when the solid sleeve cores are split. The possibility of splitting an NC core implies an innovative technique due to the brittleness of this material. Thus, the results obtained from this research make it possible to evaluate this sample’s effectiveness compared to the polycrystalline ones. This characterization is carried out by the introduction of different gaps between the different split-cores and analyzing their behavior in terms of relative permeability and impedance. The results obtained experimentally are corroborated with the results obtained by a finite element method (FEM) simulation model with the aim of determining the performance of each material when it is used as an openable core clamp.

scholarly journals Prediction of Low-Voltage Tetrafluoromethane Emissions Based on the Operating Conditions of an Aluminium Electrolysis Cell

JOM ◽  
2016 ◽  
Vol 68 (9) ◽  
pp. 2472-2482 ◽  
Author(s):  
Lukas Dion ◽  
László I. Kiss ◽  
Sándor Poncsák ◽  
Charles-Luc Lagacé
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
Electrolysis Cell ◽  
Aluminium Electrolysis

scholarly journals Tracking structural evolution: operando regenerative CeOx/Bi interface structure for high-performance CO2 electroreduction

2020 ◽  
Author(s):  
Ruichao Pang ◽  
Pengfei Tian ◽  
Hongliang Jiang ◽  
Minghui Zhu ◽  
Xiaozhi Su ◽  
...  
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Structural Evolution ◽  
Density Functional Theory Calculations ◽  
Active Phase ◽  
Interface Structure ◽  
Operating Conditions ◽  
Faradaic Efficiency ◽  
Co2 Electroreduction ◽  
Water Activation

Abstract Unveiling the structural evolution and working mechanism of catalysts under realistic operating conditions is crucial for the design of efficient electrocatalysts for CO2 electroreduction, yet remains highly challenging. Here, by virtue of operando structural measurements at multiscale levels, it is identified under CO2 electroreduction conditions that an as-prepared CeO2/BiOCl precatalyst gradually evolves into CeOx/Bi interface structure with enriched Ce3+ species, which serves as the real catalytically active phase. The derived CeOx/Bi interface structure compared to pure Bi counterpart delivers substantially enhanced performance with a formate Faradaic efficiency approaching 90% for 24 hours in a wide potential window. The formate Faradaic efficiency can be further increased by using isotope D2O instead of H2O. Density functional theory calculations suggest that the regenerative CeOx/Bi interfacial sites can not only promote water activation to increase local *H species for CO2 protonation appropriately, but also stabilize the key intermediate *OCHO in formate pathway.

scholarly journals CFD Modeling and Experimental Validation of an Alkaline Water Electrolysis Cell for Hydrogen Production

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1634
Author(s):  
Jesús Rodríguez ◽  
Ernesto Amores
Keyword(s):  
Fluid Dynamics ◽  
Hydrogen Production ◽  
Current Density ◽  
Fluid Dynamic ◽  
Water Electrolysis ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Electrolysis Cell ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water

Although alkaline water electrolysis (AWE) is the most widespread technology for hydrogen production by electrolysis, its electrochemical and fluid dynamic optimization has rarely been addressed simultaneously using Computational Fluid Dynamics (CFD) simulation. In this regard, a two-dimensional (2D) CFD model of an AWE cell has been developed using COMSOL® software and then experimentally validated. The model involves transport equations for both liquid and gas phases as well as equations for the electric current conservation. This multiphysics approach allows the model to simultaneously analyze the fluid dynamic and electrochemical phenomena involved in an electrolysis cell. The electrical response was evaluated in terms of polarization curve (voltage vs. current density) at different operating conditions: temperature, electrolyte conductivity, and electrode-diaphragm distance. For all cases, the model fits very well with the experimental data with an error of less than 1% for the polarization curves. Moreover, the model successfully simulates the changes on gas profiles along the cell, according to current density, electrolyte flow rate, and electrode-diaphragm distance. The combination of electrochemical and fluid dynamics studies provides comprehensive information and makes the model a promising tool for electrolysis cell design.

Precise quantitative addition of multiple reagents into droplets in sequence using glass fiber-induced droplet coalescence

The Analyst ◽  
2015 ◽  
Vol 140 (3) ◽  
pp. 701-705
Author(s):  
Chunyu Li ◽  
Jian Xu ◽  
Bo Ma
Keyword(s):  
Glass Fiber ◽  
Power Source ◽  
Droplet Coalescence ◽  
External Power Source ◽  
External Power ◽  
Serial Addition

Serial addition of reagents with controlled volumes is performed using a glass fiber-induced droplet coalescence method without the requirement for an external power source.

scholarly journals Noiseless intensity amplification of repetitive signals by coherent addition using the temporal Talbot effect

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Reza Maram ◽  
James Van Howe ◽  
Ming Li ◽  
José Azaña
Keyword(s):  
Optical Pulse ◽  
Wave Train ◽  
Extinction Ratio ◽  
Power Source ◽  
Wave System ◽  
Talbot Effect ◽  
Physical Processes ◽  
External Power Source ◽  
External Power ◽  
Time Average

Abstract Amplification of signal intensity is essential for initiating physical processes, diagnostics, sensing, communications and measurement. During traditional amplification, the signal is amplified by multiplying the signal carriers through an active gain process, requiring the use of an external power source. In addition, the signal is degraded by noise and distortions that typically accompany active gain processes. We show noiseless intensity amplification of repetitive optical pulse waveforms with gain from 2 to ~20 without using active gain. The proposed method uses a dispersion-induced temporal self-imaging (Talbot) effect to redistribute and coherently accumulate energy of the original repetitive waveforms into fewer replica waveforms. In addition, we show how our passive amplifier performs a real-time average of the wave-train to reduce its original noise fluctuation, as well as enhances the extinction ratio of pulses to stand above the noise floor. Our technique is applicable to repetitive waveforms in any spectral region or wave system.

Sign in / Sign up

Export Citation Format

Share Document