Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells

The chemical degradation of the perfluorinated sulfonic acid (PFSA) ion-exchange membrane as a result of an attack from a radical species, originating as a by-product of the oxygen reduction reaction, represents a significant limiting factor in a wider adoption of low-temperature proton exchange mem...

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Main Authors: Ambrož Kregar, Philipp Frühwirt, Daniel Ritzberger, Stefan Jakubek, Tomaž Katrašnik, Georg Gescheidt
Format: Article
Language:English
Published: MDPI AG 2020-10-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/13/21/5611
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author Ambrož Kregar
Philipp Frühwirt
Daniel Ritzberger
Stefan Jakubek
Tomaž Katrašnik
Georg Gescheidt
author_facet Ambrož Kregar
Philipp Frühwirt
Daniel Ritzberger
Stefan Jakubek
Tomaž Katrašnik
Georg Gescheidt
author_sort Ambrož Kregar
collection DOAJ
description The chemical degradation of the perfluorinated sulfonic acid (PFSA) ion-exchange membrane as a result of an attack from a radical species, originating as a by-product of the oxygen reduction reaction, represents a significant limiting factor in a wider adoption of low-temperature proton exchange membrane fuel cells (LT-PEMFCs). The efficient mathematical modeling of these processes is therefore a crucial step in the further development of proton exchange membrane fuel cells. Starting with an extensive kinetic modeling framework, describing the whole range of chemical processes leading to the membrane degradation, we use the mathematical method of sensitivity analysis to systematically reduce the number of both chemical species and reactions needed to efficiently and accurately describe the chemical degradation of the membrane. The analysis suggests the elimination of chemical reactions among the radical species, which is supported by the physicochemical consideration of the modeled reactions, while the degradation of Nafion backbone can be significantly simplified by lumping several individual species concentrations. The resulting reduced model features only 12 species coupled by 8 chemical reactions, compared to 19 species coupled by 23 reactions in the original model. The time complexity of the model, analyzed on the basis of its stiffness, however, is not significantly improved in the process. Nevertheless, the significant reduction in the model system size and number of parameters represents an important step in the development of a computationally efficient coupled model of various fuel cell degradation processes. Additionally, the demonstrated application of sensitivity analysis method shows a great potential for further use in the optimization of models of operation and degradation of fuel cell components.
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spelling doaj.art-7b9afc9086ac4b80a54aec5d6bb3c4bd2023-11-20T18:41:13ZengMDPI AGEnergies1996-10732020-10-011321561110.3390/en13215611Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel CellsAmbrož Kregar0Philipp Frühwirt1Daniel Ritzberger2Stefan Jakubek3Tomaž Katrašnik4Georg Gescheidt5Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, SloveniaInstitute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, AustriaInstitute of Mechanics and Mechatronics, TU Wien, Getreidemarkt 9/E325, 1060 Vienna, AustriaInstitute of Mechanics and Mechatronics, TU Wien, Getreidemarkt 9/E325, 1060 Vienna, AustriaFaculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, SloveniaInstitute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, AustriaThe chemical degradation of the perfluorinated sulfonic acid (PFSA) ion-exchange membrane as a result of an attack from a radical species, originating as a by-product of the oxygen reduction reaction, represents a significant limiting factor in a wider adoption of low-temperature proton exchange membrane fuel cells (LT-PEMFCs). The efficient mathematical modeling of these processes is therefore a crucial step in the further development of proton exchange membrane fuel cells. Starting with an extensive kinetic modeling framework, describing the whole range of chemical processes leading to the membrane degradation, we use the mathematical method of sensitivity analysis to systematically reduce the number of both chemical species and reactions needed to efficiently and accurately describe the chemical degradation of the membrane. The analysis suggests the elimination of chemical reactions among the radical species, which is supported by the physicochemical consideration of the modeled reactions, while the degradation of Nafion backbone can be significantly simplified by lumping several individual species concentrations. The resulting reduced model features only 12 species coupled by 8 chemical reactions, compared to 19 species coupled by 23 reactions in the original model. The time complexity of the model, analyzed on the basis of its stiffness, however, is not significantly improved in the process. Nevertheless, the significant reduction in the model system size and number of parameters represents an important step in the development of a computationally efficient coupled model of various fuel cell degradation processes. Additionally, the demonstrated application of sensitivity analysis method shows a great potential for further use in the optimization of models of operation and degradation of fuel cell components.https://www.mdpi.com/1996-1073/13/21/5611fuel cellPEMFCchemical membrane degradationperfluorinated sulfonic acid membranereactive oxygen speciesmodeling
spellingShingle Ambrož Kregar
Philipp Frühwirt
Daniel Ritzberger
Stefan Jakubek
Tomaž Katrašnik
Georg Gescheidt
Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells
Energies
fuel cell
PEMFC
chemical membrane degradation
perfluorinated sulfonic acid membrane
reactive oxygen species
modeling
title Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells
title_full Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells
title_fullStr Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells
title_full_unstemmed Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells
title_short Sensitivity Based Order Reduction of a Chemical Membrane Degradation Model for Low-Temperature Proton Exchange Membrane Fuel Cells
title_sort sensitivity based order reduction of a chemical membrane degradation model for low temperature proton exchange membrane fuel cells
topic fuel cell
PEMFC
chemical membrane degradation
perfluorinated sulfonic acid membrane
reactive oxygen species
modeling
url https://www.mdpi.com/1996-1073/13/21/5611
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