Modeling and Performance Simulation of a Reformer and Fuel Cell System for Electricity Generation From Digester Gas Using PEM Fuel Cells

2017 ◽  
Author(s):  
Sebastian Roa Prada ◽  
Oscar Eduardo Rueda Sanchez

Wastewater treatment plants help removing organic matter from wastewater, and at the same time, generate digester gas as a useful byproduct. Digester gas is rich in methane, which can be used to generate electricity. Fuel cell systems are the cleanest technology for power recovery from digester gas, since all other technologies generate electricity by burning all the digester gas. The most commonly used type of fuel cell for power generation from digester gas in wastewater treatment plants is the molten carbonate fuel cell. This type of fuel cell can tolerate the impurities usually found in digester gas, such as CO2 and H2S; however, this kind of fuel cell systems is more suitable for large wastewater treatment plants. This prevents the use of fuel cells for power generation from digester gas in wastewater treatment plants serving medium and small size cities, or even farms. This research attempts to explore solutions to make fuel cell technologies technically and economically feasible for medium and small size wastewater treatment plants. The most suitable type of fuel cells for small applications is the Proton Exchange Membrane, PEM, fuel cell. The main challenge in using PEM fuel cells for power recovery from digester gas is that they are highly sensitive to impurities in its hydrogen gas supply. Therefore, in order to use PEM fuel cells in this application, energy must be spent in cleaning the digester gas before it enters the PEM fuel cell and reformer system. Energy is also required in the form of heat by the reformer system to produce the hydrogen needed by the fuel cell. Both the energy used in the cleaning of the digester gas and the hydrogen generation process comes from burning part of the digester gas. This reduces the amount of digester gas available for hydrogen production and electricity generation, respectively. The approach followed in this investigation seeks to develop a Simulink® model of the reformer and fuel cell so that the modeling tools of Matlab® can be used to simulate the performance of the system under different operating conditions. A sensitivity analysis is carried out to identify critical operating parameters affecting the performance of the overall system. The results obtained in this work provide guidelines for future studies of performance optimization and optimal control using the tools available in Matlab®, in order to get maximum electricity generation from digester gas using PEM fuel cell systems.

2005 ◽  
Vol 2 (4) ◽  
pp. 226-233 ◽  
Author(s):  
Shaoduan Ou ◽  
Luke E. K. Achenie

Artificial neural network (ANN) approaches for modeling of proton exchange membrane (PEM) fuel cells have been investigated in this study. This type of data-driven approach is capable of inferring functional relationships among process variables (i.e., cell voltage, current density, feed concentration, airflow rate, etc.) in fuel cell systems. In our simulations, ANN models have shown to be accurate for modeling of fuel cell systems. Specifically, different approaches for ANN, including back-propagation feed-forward networks, and radial basis function networks, were considered. The back-propagation approach with the momentum term gave the best results. A study on the effect of Pt loading on the performance of a PEM fuel cell was conducted, and the simulated results show good agreement with the experimental data. Using the ANN model, an optimization model for determining optimal operating points of a PEM fuel cell has been developed. Results show the ability of the optimizer to capture the optimal operating point. The overall goal is to improve fuel cell system performance through numerical simulations and minimize the trial and error associated with laboratory experiments.


2022 ◽  
Vol 334 ◽  
pp. 05002
Author(s):  
Andrea Pietra ◽  
Marco Gianni ◽  
Nicola Zuliani ◽  
Stefano Malabotti ◽  
Rodolfo Taccani

This study is focused on the possible application of hydrogen-fed PEM fuel cells on board ships. For this purpose, a test plant including a 100 kW generator suitable for marine application and a power converter including a supercapacitor-based energy storage system has been designed, built and experimentally characterised. The plant design integrates standard industrial components suitable for marine applications that include the technologies with the highest degree of maturity currently available on the market. Fuel Cell generator and power converter have been specifically designed by manufacturers to fit the specific plant needs. The experimental characterisation of the plant has been focused on the evaluation of the efficiency of the single components and of the overall system. Results shows a PEM fuel cell efficiency of 48% (when all auxiliaries are included) and an overall plant efficiency, including power conditioning, of about 45%. From load variation response tests, the fuel cell response time was maximum 2 seconds without supercapacitors and increased up to 20 seconds with supercapacitors connected, reducing the stress on the fuel cell generator. Experimental results confirm that PEM fuel cells, when supported by a suitably sized energy storage system, represent a viable technical solution for zero-emission power generation on board ships.


2021 ◽  
Vol 19 ◽  
pp. 7-11
Author(s):  
B. Day ◽  
A. Pourmovahed ◽  

Fuel cells are becoming an increasingly more enticing option to power drones for extended use applications. This is because under certain conditions, fuel cell systems are able to more efficiently store fuel and, therefore, energy compared to standard battery options. This reality has been proven through multiple research efforts and is reviewed in this paper. It is necessary to review the current state of PEM fuel cell technology for drone applications to determine the extent of its limitations and feasibility. For this reason, the latest developments in low temperature and high temperature PEM fuel cells were studied including their limitations and sensitivity to contamination with a focus on drone applications. It has been reported that hydrogen powered fuel cell systems are more efficient than conventional battery applications when the energy content is higher than 4 MJ. A hybrid fuel cell and battery powertrain is preferred for the purpose of counterbalancing the deficiencies of both individual cases. Currently available products were explored, and it was found that there are fuel cell systems available that are capable of powering drones in excess of 23 kg (50 lb).


Author(s):  
Nicholas Siefert ◽  
Gautam Ashok

Generating electricity at wastewater treatment plants is a promising near-term application of fuel cell systems. The scale of most wastewater treatment plants is such that there is a good match with the scale of today’s fuel cell systems. This paper presents an exergy analysis and an economic comparison between two fuel cell systems that generate electricity at a wastewater treatment plant. The first process integrates an anaerobic digester (AD) with a solid oxide fuel cell (SOFC). The SOFC was modeled using publicly-available data from the tests on the Rolls-Royce pressurized SOFC. The second process has the wastewater sent directly to a microbial fuel cell (MFC). An MFC is an electrochemical cell in which bacteria convert acetate, sugars and/or other chemicals into protons, electrons and carbon dioxide at the anode electrode. The MFC was modeled as a PEM fuel cell as used for vehicle applications, but with a few changes: (a) anaerobic bacteria, such as geobacter, grow directly on the surface of the anode electrode, (b) there is no anode gas diffusion layer (GDL), (c) iron pyrophyrin, rather than platinum, is used as the catalyst material on the anode, in addition to the bacteria, and (d) the Nafion electrolyte is replaced with a bipolar membrane in order to minimize the transfer of non-proton cations, such as Na+, from the anode to the cathode. The rest of the equipment in the MFC is the same as those in commercial vehicle PEM fuel cells in order to use recent DOE cost estimates for PEM fuel cell systems. In both cases, we generated V-i curves of SOFC and MFC-PEM systems from data available on a) PEM & SOFC electrolyte conductivity and b) anode and cathode exchange current densities, including the effect of platinum levels on the cathode exchange current density of PEM fuel cells. A full exergy analysis was conducted for both systems modeled. The power per inlet exergy will be presented as a function of the current density and the pressure of the fuel cell. Using various Department of Eneregy (DOE) cost estimates for fuel cell systems, we perform parametric studies for both the MFC and AD-SOFC systems in order to maximize the internal rate of return on investment (IRR). In the MFC case, we varied the platinum loading on the cathode in order to maximize the IRR, and in the AD-SOFC case, we varied the current density of the SOFC in order to maximize the IRR. Finally, we compare the IRR of the two systems modeled above with the IRR of an anaerobic digester integrated with a piston engine capable of operating on biogas, such as the GE Jenbacher. Using an electricity sale price of $80/MWh, the IRR of the AD-SOFC, the microbial fuel cell and the AD-piston engine were 9%/yr, 10%/yr and 2%/yr, respectively. This economic analysis suggests that further experimental research should be conducted on both the microbial fuel cell and the pressurized SOFC because both systems were able to generate attractive values of IRR at an electricity sale price close to the average industrial price of electricity in the US.


2021 ◽  
Vol 19 ◽  
pp. 7-11
Author(s):  
B. Day ◽  
A. Pourmovahed ◽  

Fuel cells are becoming an increasingly more enticing option to power drones for extended use applications. This is because under certain conditions, fuel cell systems are able to more efficiently store fuel and, therefore, energy compared to standard battery options. This reality has been proven through multiple research efforts and is reviewed in this paper. It is necessary to review the current state of PEM fuel cell technology for drone applications to determine the extent of its limitations and feasibility. For this reason, the latest developments in low temperature and high temperature PEM fuel cells were studied including their limitations and sensitivity to contamination with a focus on drone applications. It has been reported that hydrogen powered fuel cell systems are more efficient than conventional battery applications when the energy content is higher than 4 MJ. A hybrid fuel cell and battery powertrain is preferred for the purpose of counterbalancing the deficiencies of both individual cases. Currently available products were explored, and it was found that there are fuel cell systems available that are capable of powering drones in excess of 23 kg (50 lb).


Author(s):  
Marta Gandiglio ◽  
Andrea Lanzini ◽  
Alicia Soto ◽  
Pierluigi Leone ◽  
Massimo Santarelli

2015 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Verma ◽  
R. Pitchumani

Polymer electrolyte membrane (PEM) fuel cells are well suited for automotive applications compared to other types of fuel cells owing to their faster transient response and low-temperature operation. Due to rapid change in loads during automotive applications, study of dynamic behavior is of paramount importance. This study focuses on elucidating the transient response of a PEM fuel cell for specified changes in operating parameters, namely, voltage, pressure, and stoichiometry at the cathode and the anode. Transient numerical simulations are carried out for a single-channel PEM fuel cell to illustrate the response of power as the operating parameters are subjected to specified changes. These parameters are also optimized with an objective to match the power requirements of an automotive drive cycle over a certain period of time.


2019 ◽  
Vol 30 (4) ◽  
pp. 2077-2097 ◽  
Author(s):  
Zhenxiao Chen ◽  
Derek Ingham ◽  
Mohammed Ismail ◽  
Lin Ma ◽  
Kevin J. Hughes ◽  
...  

Purpose The purpose of this paper is to investigate the effects of hydrogen humidity on the performance of air-breathing proton exchange membrane (PEM) fuel cells. Design/methodology/approach An efficient mathematical model for air-breathing PEM fuel cells has been built in MATLAB. The sensitivity of the fuel cell performance to the heat transfer coefficient is investigated first. The effect of hydrogen humidity is also studied. In addition, under different hydrogen humidities, the most appropriate thickness of the gas diffusion layer (GDL) is investigated. Findings The heat transfer coefficient dictates the performance limiting mode of the air-breathing PEM fuel cell, the modelled air-breathing fuel cell is limited by the dry-out of the membrane at high current densities. The performance of the fuel cell is mainly influenced by the hydrogen humidity. Besides, an optimal cathode GDL and relatively thinner anode GDL are favoured to achieve a good performance of the fuel cell. Practical implications The current study improves the understanding of the effect of the hydrogen humidity in air-breathing fuel cells and this new model can be used to investigate different component properties in real designs. Originality/value The hydrogen relative humidity and the GDL thickness can be controlled to improve the performance of air-breathing fuel cells.


2004 ◽  
Vol 19 (6) ◽  
pp. 1723-1729 ◽  
Author(s):  
Neil Aukland ◽  
Abdellah Boudina ◽  
David S. Eddy ◽  
Joseph V. Mantese ◽  
Margarita P. Thompson ◽  
...  

During the operation of proton exchange membrane (PEM) fuel cells, a high-resistance oxide is often formed on the cathode surface of base metal bipolar plates. Over time, this corrosion mechanism leads to a drop in fuel cell efficiency and potentially to complete failure. To address this problem, we have developed alloys capable of forming oxides that are both conductive and chemically stable under PEM fuel cell operating conditions. Five alloys of titanium with tantalum or niobium were investigated. The oxides were formed on the alloys by cyclic voltammetry in solutions mimicking the cathode- and anode-side environment of a PEM fuel cell. The oxides of all tested alloys had lower surface resistance than the oxide of pure titanium. We also investigated the chemical durability of Ti–Nb and Ti–Ta alloys in more concentrated solutions beyond those typically found in PEM fuel cells. The oxide films formed on Ti–Nb and Ti–Ta alloys remained conductive and chemically stable in these concentrated solutions. The stability of the oxide films was evaluated; Ti alloys having 3% Ta and Nb were identified as potential candidates for bipolar plate materials.


Author(s):  
M. I. Rosli ◽  
M. Pourkashanian ◽  
D. B. Ingham ◽  
L. Ma ◽  
D. Borman ◽  
...  

This paper reviews some of the previous research works on direct visualisation inside PEM fuel cells via a transparent single cell for the water behaviour investigation. Several papers which have employed the method have been selected and summarised and a comparison between the design of the cell, materials, methods and visual results are presented. The important aspects, advantages of the method and a summary on the previous work are discussed. Some initial work on transparent PEM fuel cell design using a single serpentine flow-field pattern is described. The results show that the direct visualisation via transparent PEM fuel cells could be one potential technique for investigating the water behavior inside the channels and a very promising way forward to provide useful data for validation in PEM fuel cell modelling and simulation.


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