Study of an Electrochemical Alcohol Concentration Sensor: Optimization of the Anode Structure

2006 ◽  
Vol 4 (3) ◽  
pp. 345-349 ◽  
Author(s):  
Mauro Sgroi ◽  
Gianluca Bollito ◽  
Gianfranco Innocenti ◽  
Guido Saracco ◽  
Stefania Specchia ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cell ◽  
Platinum Catalyst ◽  
Water Solution ◽  
Limiting Current ◽  
Polymeric Membrane ◽  
Power Sources ◽  
Alcohol Water ◽  
Steady State Current ◽  
Micro Power

Micro power sources have a wide potential market for consumer electronics and portable applications, such as weather stations, medical devices, signal units, APU (auxiliary power units), gas sensors, and security cameras. A micro power source could be the direct methanol fuel cell system (DMFC). An important aspect of this system is the precise control of the concentration of the alcohol-water solution fed to the anode. Different detection principles were taken into consideration: electrochemical, infrared spectroscopy, gas chromatography, refractometry, density measurements, ultraviolet absorption. The present work is devoted to the study of an electrochemical amperometric sensor. The device is based on the electro-oxidation of methanol to carbon dioxide on platinum catalyst into a polymeric-membrane fuel cell operated as a galvanic cell. The alcohol-water solution under examination is fed to the anode (positive side) of a polymeric membrane fuel cell, where it reacts with water to produce carbon dioxide, protons, and electrons. Protons diffuse through the electrolyte material and recombine with electrons on the cathode catalyst (negative side). At high potentials (>0.7V) mass transfer of methanol to the electrode solution interface controls the observed current. Therefore, it is possible to correlate the solution concentration to the observed limiting current. This method was successfully applied to relatively diluted solutions (concentration <1M). The application of this principle to more concentrate solutions (up to 2M) requires an optimization of the anode structure to enhance the influence of mass transport limitation. Moreover, during continuous operation of the sensor, a decay of the signal was observed: the absence of a steady-state current value hinders the application of the sensor. An explanation of this phenomenon and a possible solution strategy are proposed.

scholarly journals Optimization of the Catalytic Layer for Alkaline Fuel Cells Based on Fumatech Membranes and Ionomer

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1353
Author(s):  
David Sebastián ◽  
Giovanni Lemes ◽  
José M. Luque-Centeno ◽  
María V. Martínez-Huerta ◽  
Juan I. Pardo ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Anion Exchange ◽  
Layer Structure ◽  
Water Solution ◽  
Membrane Thickness ◽  
Catalytic Layer ◽  
Anion Exchange Membranes ◽  
Fuel Cell Performance ◽  
Alcohol Water

Polymer electrolyte fuel cells with alkaline anion exchange membranes (AAEMs) have gained increasing attention because of the faster reaction kinetics associated with the alkaline environment compared to acidic media. While the development of anion exchange polymer membranes is increasing, the catalytic layer structure and composition of electrodes is of paramount importance to maximize fuel cell performance. In this work, we examine the preparation procedures for electrodes by catalyst-coated substrate to be used with a well-known commercial AAEM, Fumasep® FAA-3, and a commercial ionomer of the same nature (Fumion), both from Fumatech GmbH. The anion exchange procedure, the ionomer concentration in the catalytic layer and also the effect of membrane thickness, are investigated as they are very relevant parameters conditioning the cell behavior. The best power density was achieved upon ion exchange of the ionomer by submerging the electrodes in KCl (isopropyl alcohol/water solution) for at least one hour, two exchange steps, followed by treatment in KOH for 30 min. The optimum ionomer (Fumion) concentration was found to be close to 50 wt%, with a relatively narrow interval of functioning ionomer percentages. These results provide a practical guide for electrode preparation in AAEM-based fuel cell research.

scholarly journals Application of a Hydrophobic Polymeric Membrane for Carbon Dioxide Desorption from an Mea-Water Solution

2017 ◽  
Vol 45 (2) ◽  
pp. 45-49
Author(s):  
Zenon Ziobrowski ◽  
Adam Rotkegel
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Multilayer Film ◽  
Liquid Flow Rate ◽  
Water Solution ◽  
Polymeric Membrane ◽  
Operating Parameters ◽  
Ceramic Support ◽  
Temperature Liquid ◽  
Feed Temperature

Abstract Carbon dioxide desorption from a monoethanolamine (MEA) solution using a hydrophobic polydimethylsiloxane (PDMS) tubular membrane on a ceramic support is presented. The effects of operating parameters such as feed temperature, liquid flow rate and MEA concentration on mass transfer were examined. The mass transfer of CO2 from the liquid to gaseous phase was predicted by a multilayer film model with an accuracy of ±25%. Research into new selective materials is needed to develop more efficient and environmentally friendly CO2 capture technology

Characterization of a Polymeric Membrane for the Separation of Hydrogen in a Mixture with CO2

2016 ◽  
Vol 9 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Dionisio H. Malagón-Romero ◽  
Alexander Ladino ◽  
Nataly Ortiz ◽  
Liliana P. Green
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Production ◽  
Test Performance ◽  
Low Cost ◽  
Time Lag ◽  
Polymeric Membrane ◽  
Biological Processes ◽  
Scanning Calorimetry ◽  
Environmentally Sustainable ◽  
Production Of Hydrogen

Hydrogen is expected to play an important role as a clean, reliable and renewable energy source. A key challenge is the production of hydrogen in an economically and environmentally sustainable way on an industrial scale. One promising method of hydrogen production is via biological processes using agricultural resources, where the hydrogen is found to be mixed with other gases, such as carbon dioxide. Thus, to separate hydrogen from the mixture, it is challenging to implement and evaluate a simple, low cost, reliable and efficient separation process. So, the aim of this work was to develop a polymeric membrane for hydrogen separation. The developed membranes were made of polysulfone via phase inversion by a controlled evaporation method with 5 wt % and 10 wt % of polysulfone resulting in thicknesses of 132 and 239 micrometers, respectively. Membrane characterization was performed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and ASTM D882 tensile test. Performance was characterized using a 23 factorial experiment using the time lag method, comparing the results with those from gas chromatography (GC). As a result, developed membranes exhibited dense microstructures, low values of RMS roughness, and glass transition temperatures of approximately 191.75 °C and 190.43 °C for the 5 wt % and 10 wt % membranes, respectively. Performance results for the given membranes showed a hydrogen selectivity of 8.20 for an evaluated gas mixture 54% hydrogen and 46% carbon dioxide. According to selectivity achieved, H2 separation from carbon dioxide is feasible with possibilities of scalability. These results are important for consolidating hydrogen production from biological processes.

scholarly journals Optimal Synergy between Photovoltaic Panels and Hydrogen Fuel Cells for Green Power Supply of a Green Building—A Case Study

2021 ◽  
Vol 13 (11) ◽  
pp. 6304
Author(s):  
Raluca-Andreea Felseghi ◽  
Ioan Așchilean ◽  
Nicoleta Cobîrzan ◽  
Andrei Mircea Bolboacă ◽  
Maria Simona Raboaca
Keyword(s):  
Carbon Dioxide ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Power Supply ◽  
Carbon Dioxide Emissions ◽  
Green Building ◽  
Energy System ◽  
Generation System ◽  
Photovoltaic Panels

Alternative energy resources have a significant function in the performance and decarbonization of power engendering schemes in the building application domain. Additionally, “green buildings” play a special role in reducing energy consumption and minimizing CO2 emissions in the building sector. This research article analyzes the performance of alternative primary energy sources (sun and hydrogen) integrated into a hybrid photovoltaic panel/fuel cell system, and their optimal synergy to provide green energy for a green building. The study addresses the future hydrogen-based economy, which involves the supply of hydrogen as the fuel needed to provide fuel cell energy through a power distribution infrastructure. The objective of this research is to use fuel cells in this field and to investigate their use as a green building energy supply through a hybrid electricity generation system, which also uses photovoltaic panels to convert solar energy. The fuel cell hydrogen is supplied through a distribution network in which hydrogen production is outsourced and independent of the power generation system. The case study creates virtual operating conditions for this type of hybrid energy system and simulates its operation over a one-year period. The goal is to demonstrate the role and utility of fuel cells in virtual conditions by analyzing energy and economic performance indicators, as well as carbon dioxide emissions. The case study analyzes the optimal synergy between photovoltaic panels and fuel cells for the power supply of a green building. In the simulation, an optimally configured hybrid system supplies 100% of the energy to the green building while generating carbon dioxide emissions equal to 11.72% of the average value calculated for a conventional energy system providing similar energy to a standard residential building. Photovoltaic panels account for 32% of the required annual electricity production, and the fuel cells generate 68% of the total annual energy output of the system.

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