scholarly journals Thermodynamic Study of Operation Properties Effect on Polymer Electrolyte Membrane Fuel Cells (PEM)

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ibrahim H Tawil ◽  
Farag M Bsebsu ◽  
Hassan Abdulkader

The thermodynamic analysis of PEM fuel cell energy production depends on the entropy and enthalpy of reaction with the changing of the operating temperatures that ranges between 50 and 100ºC, the electrical work done will be equal to the Gibbs free energy released. This paper presents a mathematical model of PEM fuel cells, based on physical-chemical procedures of the phenomena occurring inside the fuel cell, and it was theoretically studied the performance at different operation variables and conditions. The C++ program is designed to calculate all thermo-chemical parameters, i.e. enthalpy of formation, Gibbs free energy, work and efficiency for any type of fuel cells. The results are plotted as a function of fuel cell operating temperature. The results shows that the highest value of Gibbs energy is at the lowest operating temperature, and decreases gradually with increasing the temperature, the output voltage is determined by cell’s reversible voltage that arises from potential difference produced by chemical reaction and several voltage losses that occur inside a cell. In addition the results showed that the efficiency of this type of the fuel cells is much higher than the ideal Carnot’s efficiency, it changes between 82% to 85% depends on temperature operation. The heat output (required heat) from the fuel cell increases with increasing the operating temperature, this heat is used for many thermal applications such as buildings space heating.

Author(s):  
Thomas A. Trabold

This paper provides an overview of the application of minichannels, typically on the order of 1 mm hydraulic diameter, in the design of polymer electrolyte membrane (PEM) fuel cells. In these electrochemical devices, minichannels deliver reactant hydrogen and oxygen to the anode and cathode electrodes, respectively, while transporting product water out of the cell. The channels must be designed for low pressure drop, to avoid excessive parasitic power losses from gas handling equipment. However, the channels also need to operate in a flow regime in which the overall water balance in the fuel cell can be maintained. The various aspects of minichannel design, including size and cross-sectional shape, are discussed, with particular emphasis on fuel cell water management. In addition to reviewing these fundamental aspects of minichannel design, examples are given of new experimental tools currently under development which are applied to relate channel water transport and accumulation to fuel cell performance.


Author(s):  
A. A. Tahrim ◽  
I. N. H. M. Amin

High-temperature polymer electrolyte membrane fuel cell as a sustainable green technology has been developed throughout the years as it provides several benefits compared to Nafion-based fuel cells (e.g., CO tolerance, improved kinetic and enhance water management). Polybenzimidazole which one of the best membrane candidates was extensively studied due to excellent properties to be used in high-temperature application. Impregnating polybenzimidazole with phosphoric acid are most commonly practised as an electrolyte membrane in the PEMFC. In this paper, recent advancement of the existing literature regarding work revolving polybenzimidazole to improve the performance of phosphoric acid doped polybenzimidazole membrane for high-temperature polymer electrolyte membrane fuel cell are reviewed. Notable works such as using aluminium containing silicate (Al-Si), silicon carbide whisker (mSiC) and sulfonated graphene oxide in the composite PBI derivatives were observed. Proton conductivity are recorded at 0.371, 0.271 and 0.280 S/cm, respectively.


2021 ◽  
Author(s):  
Seungju Lee ◽  
YoungSuk Jo ◽  
Son-Jong Hwang ◽  
Yongha Park ◽  
Yeong Cheon Kim ◽  
...  

Abstract Modern H2-based energy storage and conversion devices require a polymer electrolyte membrane (PEM) fuel cell–based integrated power system with synergistic heat integration. The key issue in integrated power systems is developing a PEM that can operate at 200–300 °C. However, currently used phosphoric-acid-based high-temperature PEM fuel cells limited stability at higher operating temperatures. Herein, we introduce a cerium hydrogen phosphate (CeHP) PEM that conducts protons above 200 °C through a self-assembled network (SAN). The SAN-CeHP-PBI reached maximum power densities of 2.4 W cm-2 and operate stably for over 7000 minute without any voltage decay at 250 ℃ under H2/O2 and anhydrous conditions. The developed fuel cell can be combined with an external hydrogen generator that uses a liquid hydrogen carrier such as N-ethylcarbazole and methanol as fuel, thus achieving a high energy efficiency. The thermal stability and fuel flexibility of these SAN-CeHP-PBI demonstrate potential for commercial applications.


2021 ◽  
Author(s):  
Gokul Venugopalan ◽  
Deepra Bhattacharya ◽  
Subarna Kole ◽  
Cameron Ysidron ◽  
Polyxeni P. Angelopoulou ◽  
...  

Ionomer electrode binders are important materials for polymer electrolyte membrane (PEM) fuel cells and electrolyzers and have a profound impact on cell performance. Herein, we report the effect of two...


2014 ◽  
Vol 4 (5) ◽  
pp. 1400-1406 ◽  
Author(s):  
Yuta Nabae ◽  
Mayu Sonoda ◽  
Chiharu Yamauchi ◽  
Yo Hosaka ◽  
Ayano Isoda ◽  
...  

A Pt-free cathode catalyst for polymer electrolyte membrane fuel cells has been developed by multi-step pyrolysis of Fe phthalocyanine and phenolic resin and shows a quite promising fuel cell performance.


Author(s):  
Erman Çelik ◽  
İrfan Karagöz

Polymer electrolyte membrane fuel cells are carbon-free electrochemical energy conversion devices that are appropriate for use as a power source on vehicles and mobile devices emerging with their high energy density, lightweight structure, quick startup and lower operating temperature capabilities. However, they need more developments in the aspects of reactant distribution, less pressure drops, precisely balanced water content and heat management to achieve more reliable and higher overall cell performance. Flow field development is one of the most important fields of study to increase cell performance since it has decisive effects on performance parameters, including bipolar plate, and thus fuel cell weight. In this study, recent developments on conventional flow field designs to eliminate their weaknesses and innovative design approaches and flow field architectures are obtained from patent databases, and both numerical and experimental scientific studies. Fundamental designs that create differences are introduced, and their effects on the performance are discussed with regard to origin, objective, innovation strategy of design besides their strength and probable open development ways. As a result, significant enhancements and design strategies on flow field designs in polymer electrolyte membrane fuel cells are summarized systematically to guide prospective flow field development studies.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shadi Vafaeyan ◽  
Alain St-Amant ◽  
Marten Ternan

The use of propane fuel in high temperature (120°C) polymer electrolyte membrane (PEM) fuel cells that do not require a platinum group metal catalyst is being investigated in our laboratory. Density functional theory (DFT) was used to determine propane adsorption energies, desorption energies, and transition state energies for both dehydrogenation and hydroxylation reactions on a Ni(100) anode catalyst surface. The Boltzmann factor for the hydroxylation of a propyl species to form propanol and its subsequent desorption was compared to that for the dehydrogenation of a propyl species. The large ratio of the respective Boltzmann factors indicated that the formation of a completely reacted product (carbon dioxide) is much more likely than the formation of partially reacted products (alcohols, aldehydes, carboxylic acids, and carbon monoxide). That finding is evidence for the major proportion of the chemical energy of the propane fuel being converted to either electrical or thermal energy in the fuel cell rather than remaining unused when partially reacted species are formed.


Author(s):  
Yanxia Zhao ◽  
Renwei Mei ◽  
James F. Klausner

A computational model using Lattice Boltzmann Equation (LBE) method is employed to investigate the fluid transport on the anode side of Polymer Electrolyte Membrane (PEM) fuel cells, with an emphasis on mass transfer enhancement. A 3-dimensional LBE code is developed to solve the flows in the channel and the porous media in the gas diffusion layer (GDL) simultaneously. Multiple flow enhancers (obstructions in the flow channel) are placed in the channel to enhance the transversal flow across the GDL. The mass flow rate, the velocity field and the pressure distribution are analyzed. The effects of flow enhancers are assessed. The results show that the transversal flow across the GDL is enhanced by placing flow enhancers in the channel. Increasing flow enhancer size can significantly increase the transversal flow rate, with high pressure-loss through the flow channel. The results also demonstrate that the location of flow enhancers in the flow channel have a remarkable impact on the transversal flow rate. The transversal flow rate increases as the GDL porosity increases.


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