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proton-exchange-membranes
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Hydrogen production performance of a photovoltaic thermal system coupled with a proton exchange membrane electrolysis cell
, Article International Journal of Hydrogen Energy ; Volume 47, Issue 7 , 2022 , Pages 4472-4488 ; 03603199 (ISSN) ; Hakkaki Fard, A ; Jalalidil, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
As one of the cleanest energies, hydrogen has attracted much attention over the past decade. Hydrogen can be produced using water electrolysis in a Proton Exchange Membrane Electrolysis Cell (PEMEC). In the present study, the performance of the PEMEC, powered by the Photovoltaic-Thermal (PVT) system, is scrutinized. It is considered that the PVT system provides the required electrical power of the PEMEC and preheats the feedwater. A comprehensive numerical model of the coupled PVT-PEMEC system is developed. The model is used to investigate the effect of various operating parameters, including solar radiation intensity, inlet feedwater temperature, and feedwater mass flow rate, on the...
Effect of water-methanol content on the structure of Nafion in the sandwich model and solvent dynamics in nano-channels; A molecular dynamics study
, Article Molecular Physics ; Volume 109, Issue 5 , Mar , 2011 , Pages 709-724 ; 00268976 (ISSN) ; Akbarzadeh, H ; Taherkhani, F ; Parsafar, G ; Sharif University of Technology
Abstract
Continuing an ongoing study, molecular dynamics (MD) simulations were performed to investigate the effects of methanol concentration on Nafion morphology, such as the size of solvent cluster, solvent location, and polymer structure via the sandwich model. Our survey shows that high methanol concentrations resulted in increment of solvent cluster size in Nafion membrane. The sulfonic acid clusters also befall much in order as subsequent layers of such ionic clusters are formed. The number of neighbouring hydronium ions around a sulfur atom is independent of methanol concentration, but the first shell of hydronium and water around sulfonic acid clusters is broader. Although methanol would...
Properties of Nafion Under Uniaxial Loading at Different Temperatures: A Molecular Dynamics Study
, Article Polymer - Plastics Technology and Engineering ; Volume 54, Issue 8 , 2015 , Pages 806-813 ; 03602559 (ISSN) ; Naghdabadi, R ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
Nafion membrane encounters many different thermal conditions and mechanical loadings because of its wide range of applications as a proton exchange membrane (PEM). Molecular dynamics simulation of hydrated Nafion at different temperatures is carried out to investigate the alteration of the physical properties of Nafion under uniaxial loading over a wide range of temperatures. According to the simulation results, increase of the temperature reduces the yield stress. The results also show that the polymer chains ordering increases the glass transition temperature and enhances the self-diffusion coefficient of water in hydrated Nafion. Comparisons show that the elastic modulus and viscosity...
Design and simulation of a novel bipolar plate based on lung-shaped bio-inspired flow pattern for PEM fuel cell
, Article International Journal of Energy Research ; Volume 41, Issue 12 , 2017 , Pages 1730-1739 ; 0363907X (ISSN) ; Shamloo, A ; Sharif University of Technology
Abstract
Finding the optimal flow pattern in bipolar plates of a proton exchange membrane is a crucial step for enhancing the performance of the device. This design plays a critical role in fluid mass transport through microporous layers, charge transfer through conductive media, management of the liquid water produced in microchannels, and microporous layers and heat management in fuel cells. This article investigates different types of common flow patterns in bipolar plates while considering a uniform pressure and velocity distribution as well as a uniform distribution of reactants through all the surfaces of the catalyst layer as the design criteria so that there would be a consistent electron...
Integrated and inherently safe design and operation of a mobile power generation: Process intensification through microreactor reformer and HT-PEMFC
, Article International Journal of Hydrogen Energy ; Volume 46, Issue 46 , 2021 , Pages 23839-23854 ; 03603199 (ISSN) ; Sharifzadeh, M ; Rashtchian, D ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In the present study, due to various advantages of process miniaturization, the integrated design and operation of a mobile power generation system consisting of a microreactor reformer and a proton exchange membrane fuel cell (PEMFC) are investigated. The hydrogen fuel is supplied through autothermal steam-reforming of methanol in a microreactor leading to a safer, as well as more efficient, and economical operation. A high-temperature polymer membrane fuel cell with external accessories is applied for power generation. Then, simulation-optimization programming is applied for simultaneously optimizing the process design and operation at the same level. The result shows that the implemented...
Hydrogen production performance of a photovoltaic thermal system coupled with a proton exchange membrane electrolysis cell
, Article International Journal of Hydrogen Energy ; 2021 ; 03603199 (ISSN) ; Hakkaki Fard, A ; Jalalidil, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
As one of the cleanest energies, hydrogen has attracted much attention over the past decade. Hydrogen can be produced using water electrolysis in a Proton Exchange Membrane Electrolysis Cell (PEMEC). In the present study, the performance of the PEMEC, powered by the Photovoltaic-Thermal (PVT) system, is scrutinized. It is considered that the PVT system provides the required electrical power of the PEMEC and preheats the feedwater. A comprehensive numerical model of the coupled PVT-PEMEC system is developed. The model is used to investigate the effect of various operating parameters, including solar radiation intensity, inlet feedwater temperature, and feedwater mass flow rate, on the...
Construction of The Catalyst Layer of a PEM Fuel Cell Using Electrospray Method
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammad Reza (Supervisor)
Abstract
Due to Reduction of fossil fuels resources and the pollution caused by using them, it seems inevitable to shift to using reproducible energies. Among different resource of reproducible energy, fuel cell is one of suitable technologies for investigation and development. Fuel cell is an electrochemical system to convert chemical energy of fuel directly to electrical energy. Each fuel cell has seven part (two Bipolar Plate, two electrode, two catalyst layer and polymeric Membrane). Oxidation occur in anode of fuel cell and created electron enters external circuit and then riches the cathode. The positive ion created in the anode reaches the cathode through the membrane (electrolyte) and...
State Feedback Control Proton Exchange Membrane Fuel Cell (Pem) Stack
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor)
Abstract
In recent years, fuel cells have been proposed as an alternative option to conventional energy conversion systems. Fuel cell is an electrochemical system that can convert chemical energy to electrical energy without combustion. High efficiency, low temperature performance, poor pollution, good reliability, flexibility in the production potential, low start-up time and high life expectancy are the major advantages of this system. The most important barriers to the use of fuel cells are high cost polymer membrane and using expensive platinum catalysts. Modeling of fuel cells in general will meet two objectives. The first, due to the complexity of the processes taking place within the cell,...
An Analytical Study of The Pem Fuel Cell
, M.Sc. Thesis Sharif University of Technology ; Nouri Borujerdi, Ali (Supervisor)
Abstract
In this thesis, the quasi-two-dimensional modeling of polymer electrolyte membrane fuel cell cathode side is presented as a single phase. Polymer membrane fuel cell modeling equations are solved in the equations of continuity, momentum, and chemical species are potential equation. In this report, for modeling the electrochemical reaction in the catalyst layer of the relationship Baltr-Vollmer is used. The present analytical solution based on two fixed pressure gradient and the velocity dependent pressure gradient is developed. Momentum and continuity equations in the model with separation, velocity and pressure field is achieved. By comparing the results of the modeling analysis with...
Effects of Nano Metallic Catalysts on The Life-Time and Efficiency of Proton Exchange Membrane Fuel Cells
, M.Sc. Thesis Sharif University of Technology ; Vesaghi, Mohammad Ali (Supervisor)
Abstract
The Fuel cell is an energy converter which converts the chemical energy of a chemical reaction to electricity and heat directly and without any pollution. One of the most important types of fuel cells is the proton exchange membrane (PEM) fuel cell. The importance of PEM fuel cells is a result of their high energy density, quick start up ability, lower operating temperature, high efficiency and low or zero emissions. Catalysts play an important role in both costs and durability of PEM fuel cells. Alloying the Pt with other metals can increase the activity of the catalysts of the fuel cells and also reduces the amount of costly Pt. In this study, the nanoparticles of Ni were added to the...
Platinum nanoparticles with superacid-doped polyvinylpyrrolidone coated carbon nanotubes: Electrocatalyst for oxygen reduction reaction in high-temperature proton exchange membrane fuel cell
, Article RSC Advances ; Volume 6, Issue 48 , 2016 , Pages 41937-41946 ; 20462069 (ISSN) ; Saievar Iranizad, E ; Bayat, A ; Sharif University of Technology
Royal Society of Chemistry
2016
Abstract
In order to improve the catalytic activity and durability of proton-exchange-membrane-fuel-cells (PEMFCs), Nafion-free Pt-based catalyst using the superacid-doped polymer coated multiwall carbon nanotubes (MWCNTs) was investigated. The modification and nano polymerization of MWCNTs were developed by polyvinylpyrrolidone (PVP). The following observations were made in the presence of polymer: better dispersion of MWCNTs, higher thermal stability of MWCNT/PVP than that of pristine MWCNT up to 450 °C as tested by thermal gravimetric analysis (TGA), homogeneous distribution of Pt without agglomeration as observed by transmission electron microscope (TEM), and not too much difference in Pt loading...
The effect of variable catalyst loading in electrodes on PEM fuel cell performance
, Article 3rd International Conference on Fuel Cell Science, Engineering, and Technology, 2005, Ypsilanti, MI, 23 May 2005 through 25 May 2005 ; 2005 , Pages 145-152 ; 0791837645 (ISBN); 9780791837641 (ISBN) ; Farhanieh, B ; Sharif University of Technology
American Society of Mechanical Engineers
2005
Abstract
Catalyst layers are one the important parts of the PEM fuel cells as they are the main place for electrochemical reaction taking place in anode and cathode of the cells. The amount of catalyst loading of this layer has a large effect on PEM fuel cell performance. Non-uniformity of reactant concentration could lead to a variation of current density in anode and cathode catalyst layer. The main reason for this phenomenon is porosity variation due to two effects: 1. compression of electrode on the solid landing area and 2. Water produced at the cathode side of diffusion layer. In this study the effect of variable current density in anode and cathode electrode on cell performance is...
Modeling Reaction and Distribution of Water in Nanopores of the Cathode Catalyst Layer of PEM Fuel Cell
, M.Sc. Thesis Sharif University of Technology ; baghalha, morteza (Supervisor)
Abstract
In the proton exchange membrane fuel cells (PEM, the produced water would be divided into two phases of vapor and liquid. distribution of both liquid and vapor phases in different cell layers affects the performance, the efficiency and the life of a fuel cell significantly. Moreover, Nano pores of the cathode catalyst layer are involved with some phenomena such as electrochemical reaction kinetics, heat and mass transfer and interface phase change. One of the most important problems in the performance of fuel cells is distribution of liquid water in the porous areas. Water flooding in fuel cells causes to delay in oxygen transport to active sites in the catalyst layer because the pores of...
Directly coupled photovoltaic-electrolyzer system optimization using a novel ica methodology
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Vol. 6B, issue , 2014 ; Maroufmashat, A ; Sattari, S ; Sharif University of Technology
Abstract
Hydrogen is considered to be the fuel of the future. It is a cleaner alternative to the fossil fuels we consume every day. Of all the different hydrogen production pathways that exist, producing the gas by utilizing the power generated by renewable energy sources has been a topic of interest for many researchers across the world. The following work focuses on minimizing the energy loss by optimizing the size and the operating conditions of an electrolyzer directly connected to a photovoltaic (PV) module at different irradiance. The hydrogen, in the proposed system, is produced using a proton exchange membrane (PEM) electrolyzer. A nonlinear method is considered, because of the complexity of...
Hydrogen generation optimization in a hybrid photovoltaic-electrolyzer using intelligent techniques
, Article ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology, FUELCELL 2012 Collocated with the ASME 2012 6th International Conference on Energy Sustainability, San Diego, CA, USA, 23 July 2012 through 26 July 2012 ; July , 2012 , Pages 19-24 ; 9780791844823 (ISBN) ; Seyyedyn, F ; Roshandel, R ; Bouroshaki, M ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2012
Abstract
Hydrogen is a flexible energy carrier and storage medium and can be generated by electrolysis of water. In this research, hydrogen generation is maximized by optimizing the optimal sizing and operating condition of an electrolyzer directly connected to a PV module. The method presented here is based on Particle swarm optimization algorithm (PSO). The hydrogen, in this study, was produced using a proton exchange membrane (PEM) electrolyzer. The required power was supplied by a photovoltaic module rated at 80 watt. In order to optimize Hydrogen generation, the cell number of the electrolyser and its activity must be 9 and 3, respectively. As a result, it is possible to closely match the...
Effect of casting solvent on the characteristics of nafion/TiO2 nanocomposite membranes for microbial fuel cell application
, Article International Journal of Hydrogen Energy ; Volume 41, Issue 1 , 2016 , Pages 476-482 ; 03603199 (ISSN) ; Mousavi, S. A ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
Synthesis and characterization of Nafion/TiO2 membranes (TiO2 1 wt%) with different solvents (DMF, DMAc, NMP) for proton exchange membrane operating at Microbial Fuel Cell (MFC) was investigated in this study. Nanocomposite membranes are studied due to their better physical properties and higher production voltage in comparison with Nafion 112 in MFC systems. Nafion/TiO2 nanocomposite membranes were prepared by solution casting Method. The structures of membranes were investigated by Scanning Electron Microscopy (SEM). In addition, water uptake, proton conductivity, and ion exchange capacity (IEC) of membranes were measured and compared with Nafion 112 in microbial fuel cell. The...
Artificial neural network modeling of Pt/C cathode degradation in pem fuel cells
, Article Journal of Electronic Materials ; Volume 45, Issue 8 , 2016 , Pages 3822-3834 ; 03615235 (ISSN) ; Maleki, N ; Sharif University of Technology
Springer New York LLC
2016
Abstract
Use of computational modeling with a few experiments is considered useful to obtain the best possible result for a final product, without performing expensive and time-consuming experiments. Proton exchange membrane fuel cells (PEMFCs) can produce clean electricity, but still require further study. An oxygen reduction reaction (ORR) takes place at the cathode, and carbon-supported platinum (Pt/C) is commonly used as an electrocatalyst. The harsh conditions during PEMFC operation result in Pt/C degradation. Observation of changes in the Pt/C layer under operating conditions provides a tool to study the lifetime of PEMFCs and overcome durability issues. Recently, artificial neural networks...
Enhancement of electricity generation by a microbial fuel cell using a highly active non-precious-metal nitrogen-doped carbon composite catalyst cathode
, Article Energy and Fuels ; Volume 31, Issue 1 , 2017 , Pages 959-967 ; 08870624 (ISSN) ; Kariminia, H. R ; Chen, Z. W ; Parker, W ; Pritzker, M. D ; Legge, R. L ; Sharif University of Technology
American Chemical Society
2017
Abstract
As microbial fuel cell (MFC) technology continues to gain momentum toward commercialization, the replacement of traditionally used platinum for oxygen reduction with an inexpensive catalyst becomes more important. A nonprecious nitrogen-doped carbon composite catalyst with previous applications in PEM fuel cells is demonstrated for the first time in a single-chamber air cathode MFC with comparisons to a similar platinum-based MFC. The performance of the MFC is compared with a similar MFC using a platinum catalyst and acetate feed. When the platinum is replaced with the catalyst loaded at the surface of the proton exchange membrane (loading density of 1 mg/cm2), MFC operation outperforms a...
New blend nanocomposite membranes based on PBI/sulfonated poly(ether keto imide sulfone) and functionalized quantum dot with improved fuel cell performance at high temperatures
, Article International Journal of Energy Research ; Volume 45, Issue 15 , August , 2021 , Pages 21274-21292 ; 0363907X (ISSN) ; Rezania, H ; Vatanpour, V ; Rastgoo Deylami, M ; Rajabi, H. R ; Sharif University of Technology
John Wiley and Sons Ltd
2021
Abstract
In this work, we reported the synthesis of a sulfonated poly(ether keto imide sulfone) (SPEKIS) using a novel aromatic diol containing nitrogen heterocycles and sulfonic monomer. New nanocomposite blend membranes were prepared using obtained SPEKIS and polybenzimidazole (PBI) with the incorporation of zinc sulfide (ZnS) functionalized quantum dots (FQDs) having both -COOH and NH2 groups with a solution-casting method and were used as proton exchange membranes. The SPEKIS and ZnS FQDs were used for the first time in the preparation of new nanocomposite blend membranes based on PBI. The purpose of this study is to investigate the effect of SPEKIS and ZnS FQDs on the PBI membrane performance in...
Economically Optimal and Inherently Safe Design and Operation of Microreactor for Hydrogen Production in Portable Power Generation Devices Such as PEM Fuel Cell
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Sharifzadeh, Mehdi (Supervisor)
Abstract
Due to high efficiency and modular production ability of fuel cells, they have been used extensively in the power plants, especially in portable devices such as fuel cell vehicles. The commercialization of the equipment is dependent on ensuring the safety of their operations. Many of these platforms employ steam reforming reactions at very high temperature in order to produce the hydrogen, which is implemented as the fuel in the PEM fuel cell. The technique of miniaturization is a promising approach to design a chemical process in which the rate of transport phenomena such as the mass and heat transfer are intensified by reducing the size of the reactor and allowing the process to be run...