Modeling, Development and Preliminary Testing of a 2 MW PEM Fuel Cell Plant Fueled With Hydrogen From a Chlor-Alkali Industry

Author(s):  
Stefano Campanari ◽  
Giulio Guandalini ◽  
Jorg Coolegem ◽  
Jan ten Have ◽  
Patrick Hayes ◽  
...  

The chlor-alkali industry produces significant amounts of hydrogen as byproduct and an interesting benefit can be obtained by feeding hydrogen to a PEM fuel cell unit, whose electricity and heat production can cover part of the chemical plant consumptions. The estimated potential of such application is up to 1100 MWel installed in the sole China, a country featuring a large presence of chlor-alkali plants. This work presents the modeling, development and first experimental results from field tests of a 2 MW PEM fuel cell power plant, built within the European project DEMCOPEM-2MW and installed in Yingkou, China as the current world’s largest PEM fuel cell installation. After a preliminary introduction to the market potential of PEM Fuel cells in the chlor-alkali industry, it is first discussed an overview of project’s MEA and fuel cell development for long life stationary applications, focusing on the design-for-manufacture process and the high-volume manufacturing route developed for the 2MW plant. The work then discusses the modeling of the power plant, including a specific lumped model predicting FC stack behavior as a function of inlet streams conditions and power set point, according to regressed polarization curves. Cells performance decay vs. lifetime reflects long-term stack test data, aiming to evidence the impact on overall energy balances and efficiency of the progression of lifetime. BOP is modeled to simulate auxiliaries consumption, pressure drops and components operating conditions. The model allows studying different operational strategies that maintain the power production during lifetime, minimizing efficiency losses; as well as to investigate the optimized operating setpoint of the plant at full load and during part-load operation. The last section of the paper discusses the experimental results, through a complete analysis of the plant performance after plant startup, including energy and mass balances and allowing to validate the model. Cumulated indicators over the first nine months of operations regarding energy production, hydrogen consumption and efficiency are also discussed.

Author(s):  
Stefano Campanari ◽  
Giulio Guandalini ◽  
Jorg Coolegem ◽  
Jan ten Have ◽  
Patrick Hayes ◽  
...  

The chlor-alkali industry produces significant amounts of hydrogen as by-product which can potentially feed a polymeric electrolyte membrane (PEM) fuel cell (FC) unit, whose electricity and heat production can cover part of the chemical plant consumptions yielding remarkable energy and emission savings. This work presents the modeling, development, and experimental results of a large-scale (2 MW) PEM fuel cell power plant installed at the premises of a chlor-alkali industry. It is first discussed an overview of project’s membrane-electrode assembly and fuel cell development for long life stationary applications, focusing on the design-for-manufacture process and related high-volume manufacturing routes. The work then discusses the modeling of the power plant, including a specific lumped model predicting FC stack behavior as a function of inlet stream conditions and power set point, according to regressed polarization curves. Cells’ performance decay versus lifetime reflects long-term stack test data, aiming to evidence the impact on overall energy balances and efficiency of the progression of lifetime. Balance of plant is modeled to simulate auxiliary consumptions, pressure drops, and components’ operating conditions. The model allows studying different operational strategies that maintain the power production during lifetime, minimizing efficiency losses, as well as to investigate the optimized operating setpoint of the plant at full load and during part-load operation. The last section of the paper discusses the experimental results, through a complete analysis of the plant performance after startup, including energy and mass balances and allowing to validate the model. Cumulated indicators over the first two years of operations regarding energy production, hydrogen consumption, and efficiency are also discussed.


Author(s):  
Shan Jia ◽  
Hongtan Liu

In a PEM fuel cell, it has been shown that the compression under the land area is the main reason for the observed higher performance than that under channel areas. If the area under the channel can also benefit from such a compression the overall performance of the cell will increase. Since the areas under the channel are not directly compressed in an assembled fuel cell, it is the objective of this study to determine if a cold pre-compression treatment of the gas diffusion electrode (GDE) may have a significant positive effect on the overall performance of the cell. First, the GDE is cold pre-compressed to a level similar to the compression that would be experienced by the land areas in an assembled fuel cell. Then the pre-compressed GDE is assembled in a regular test fuel cell and the performances under various operating conditions are studied. Finally, the cell performance results are compared with the results obtained from a fuel cell with a regular GDE. The experimental results show that cold pre-compress of the GDE has significantly improved the overall performance of the fuel cell. Further experiments have also been conducted with five different levels of cold pre-compression to determine if there exists an optimal compression and its value if it exists. The experimental results show that the performance of the fuel cell first increases with the level of cold pre-compression, reaching a maximum and then decreases with the level of compression. These results clearly indicate that there indeed exists an optimal level of compression. Further studies using both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) have further corroborated the cell performance findings as well as the underlying mechanism. The results of EIS indicate that the ohmic resistance is hardly affected by the cold pre-compression, while the charge transfer resistance is significantly affected, especially in high current density region. The CV results show that the electro-chemical area (ECA) is higher with the cold pre-compressed GDE and there is an optimal compression that results in the maximum ECA. Therefore, the experimental results have shown that (a) the cold pre-compression treatment of the GDE is an effective and simple technique to increase PEM fuel cell performances; (b) there exists an optimal compression level at which the cell reaches its maximum performance; and (c) the increased performance is due to the increase of ECA resulting from the cold pre-compression treatment.


Author(s):  
Han-Sang Kim ◽  
Taehun Ha ◽  
Kyoungdoug Min

Water management is a critical operation issue for achieving the highest possible performance of proton exchange membrane (PEM) fuel cells. Quantitative determination of water and species distribution is needed to understand the water management and reactant distribution effects. In this study, the measurement of water and oxygen distributions along cathode flow channels was carried out using gas chromatography (GC). Generally, it is difficult to measure water distribution where water concentration is too high. Here, the measurement of high levels of water saturation in cathode channels was performed according to fuel cell operating conditions. GC measurement was also carried out for flooding and non-flooding conditions. To compare the experimental results with computational results, the three-dimensional CFD simulation of a unit fuel cell was performed using es-pemfc, which is the PEM fuel cell module of commercial CFD code STAR-CD. For the entrance of flow channel that has relatively lower level of water content, the calculated results showed good agreement with measured results. However, some discrepancy between calculated and experimental results was still found for the flow channels near the cathode outlet. The study provides the necessity of the development and adoption of a comprehensive multidimensional PEM fuel cell models including two-phase flow and cathode flooding phenomena for the optimization of fuel cell performance.


Author(s):  
John Fagley ◽  
Jason Conley ◽  
David Masten

In recent years, there has been an increasing amount of PEM (proton exchange membrane) fuel cell-related research conducted and subsequently published by universities and public institutions. While a good deal of this research has been useful for understanding the underlying fundamental aspects of fuel cell components and operation, much of it is not as useful for a group working on automotive applications as it could be. The reason for this is that in order to be put to practical use in an automotive application, the system being studied must meet certain constraints; satisfying targets for projected system costs, system efficiency, volumetric and gravimetric power densities (packaging), and operating conditions. For example, numerous recent publications show studies with PEM fuel cells designed and built such that limiting current density is achieved at 0.9 A/cm2 or lower, and voltages of 600 mV can only be achieved at current densities less than 0.6 A/cm2. This type of performance is sufficiently below what is required for commercial application, that any conclusions drawn from these works are difficult to extrapolate to a system of commercial automotive interest. The purpose of this article is to show, through use of engineering calculations and cost projections, what operating conditions and performance are required in a commercial automotive fuel cell application. In addition, best known (public domain) performance and corresponding conditions are given, along with Department of Energy Freedom Car targets, which can be used for state-of-the-art benchmarking. Also, reference is made to a university publication where performance (500 mV at 1.5 A/cm2) close to automotive application targets was achieved, and important aspects of their components and flow field geometry are highlighted. It is our hope that through this publication, further PEM fuel-cell related research can be directed toward the region of greatest interest for commercial, automotive application.


2005 ◽  
Vol 885 ◽  
Author(s):  
Tony Thampan ◽  
Rick Rocheleau ◽  
Keith Bethune ◽  
Douglas Wheeler

ABSTRACTAt the Hawaii Fuel Cell Test Facility a systematic evaluation of the impact of impurities in hydrogen is underway to evaluate the effects on the performance of PEM fuel cells. Initial tests are being conducted using carbon monoxide and hydrocarbon contaminants. The effects of carbon monoxide poisons at atmospheric and pressurized operating conditions have shown a strong dependence on concentration of the impurity over the range 6.7 µmole/mole to 29.3 µmole/mole. Additionally, benzene and toluene were tested at 20 µmole/mole. Although both benzene and toluene showed no evidence of fuel cell degradation, on-line gas analysis of the exit anode stream showed that toluene hydrogenation occurs in the anode resulting in 90% conversion of the toluene to methyl-cyclohexane.


2012 ◽  
Vol 532-533 ◽  
pp. 135-139
Author(s):  
Han Chieh Chiu ◽  
Jer Huan Jang ◽  
Wei Mon Yan ◽  
Chun I Lee ◽  
Chang Chung Yang

This paper experimentally investigates the dynamic response of a single fuel cell under various dynamic loadings with different operating conditions. Three kinds of loadings are applied to the PEM fuel cell and they are simulated NEDC mode, simulated 10/15 mode, and modified mode. The operating conditions are set at different cell temperatures, humidification temperatures, and stoichiometric rates during each test to study the effects of these parameters on the cell performance of a PEM fuel cell. The cell performance is found increased with increasing cell temperature in the range of 45-65°C. On the other hand, there exist optimal conditions for the humidification temperature and the stoichiometric rate at 70°C/60°C and 1.5/2.0 on the anode and cathode sides, respectively.


Author(s):  
Denise A. McKahn ◽  
Whitney McMackin

We present the design of a multi-cell, low temperature PEM fuel cell for controlled meteorological balloons. Critical system design parameters that distinguish this application are the lack of reactant humidification and cooling due to the low power production, high required power mass-density and relatively short flight durations. The cell is supplied with a pressure regulated and dead ended anode, and flow controlled cathode at variable air stoichiometry. The cell is not heated and allowed to operate with unregulated temperature. Our prototype cell was capable of achieving power densities of 43 mW/cm2/cell or 5.4 mW/g. The cell polarization performance of large format PEM fuel cell stacks is an order of magnitude greater than for miniature PEM fuel cells. These performance discrepancies are a result of cell design, system architecture, and reactant and thermal management, indicating that there are significant gains to be made in these domains. We then present design modifications intended to enable the miniature PEM fuel cell to achieve power densities of 13 mW/g, indicating that additional performance gains must be made with improvements in operating conditions targeting achievable power densities of standard PEM fuel cells.


2021 ◽  
Vol 11 (5) ◽  
pp. 2052
Author(s):  
Amlak Abaza ◽  
Ragab A. El-Sehiemy ◽  
Karar Mahmoud ◽  
Matti Lehtonen ◽  
Mohamed M. F. Darwish

In recent years, the penetration of fuel cells in distribution systems is significantly increased worldwide. The fuel cell is considered an electrochemical energy conversion component. It has the ability to convert chemical to electrical energies as well as heat. The proton exchange membrane (PEM) fuel cell uses hydrogen and oxygen as fuel. It is a low-temperature type that uses a noble metal catalyst, such as platinum, at reaction sites. The optimal modeling of PEM fuel cells improves the cell performance in different applications of the smart microgrid. Extracting the optimal parameters of the model can be achieved using an efficient optimization technique. In this line, this paper proposes a novel swarm-based algorithm called coyote optimization algorithm (COA) for finding the optimal parameter of PEM fuel cell as well as PEM stack. The sum of square deviation between measured voltages and the optimal estimated voltages obtained from the COA algorithm is minimized. Two practical PEM fuel cells including 250 W stack and Ned Stack PS6 are modeled to validate the capability of the proposed algorithm under different operating conditions. The effectiveness of the proposed COA is demonstrated through the comparison with four optimizers considering the same conditions. The final estimated results and statistical analysis show a significant accuracy of the proposed method. These results emphasize the ability of COA to estimate the parameters of the PEM fuel cell model more precisely.


Author(s):  
Jenny E. Hu ◽  
Joshua B. Pearlman ◽  
Atul Bhargav ◽  
Gregory S. Jackson

Recent advances in anode electrocatalysts for low-temperature PEM fuel cells are increasing tolerance for CO in the H2-rich anode stream. This study explores the impact of current day and future advances in CO-tolerant electrocatalysts on the system efficiency of low-temperature Nafion-based PEM fuel cell systems operating in conjunction with a hydrocarbon autothermal reformer and a preferential CO oxidation (PROx) reactor for CO clean-up. This study explores the effects of incomplete H2 cleanup by preferential oxidation reactors for partial CO removal, in combination with reformate-tolerant stacks. Empirical fuel cell performance models were based upon voltage-current characteristic from single-cell MEA tests at varying CO concentrations with new alloy reformate-tolerant electrocatalysts tested in conjunction with this study. A system-level model for a 5 kW maximum liquid-fueled system has been used to study the trade-offs between the improved performance with decreased CO concentration and the increased penalties from the air supply to the PROx reactor and associated reduction in H2 partial pressures to the anode. As CO tolerance is increased over current state-of-the-art Pt alloy catalysts system efficiencies improve due to higher fuel cell voltages. Furthermore, increasing CO tolerance of anode electrocatalysts allows for increased reformer efficiency by reducing PROx CO conversion requirements.


Author(s):  
Sang-Kyun Park ◽  
Song-Yul Choe

Performance of individual cells in an operating polymer electrolyte membrane (PEM) fuel cell stack is different from each other because of inherent manufacturing tolerances of the cell components and unequal operating conditions for the individual cells. In this paper, first, effects of different operating conditions on performance of the individual cells in a two-cell PEM fuel cell stack have been experimentally investigated. The results of the experiments showed the presence of a voltage difference between the two cells that cannot be manipulated by operating conditions. The temperature of the supplying air among others predominantly influences the individual cell voltages. In addition, those effects are explored by using a dynamic model of a stack that has been developed. The model uses electrochemical voltage equations, dynamic water balance in the membrane, energy balance, and diffusion in the gas diffusion layer, reflecting a two-phase phenomenon of water. Major design parameters and an operating condition by conveying simulations have been changed to analyze sensitivity of the parameters on the performance, which is then compared with experimental results. It turns out that proton conductivity of the membrane in cells among others is the most influential parameter on the performance, which is fairly in line with the reading from the experimental results.


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