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Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study

Pd-based membrane reformers have been substantially studied in the past as a promising reformer to produce high-purity H(2) from thermochemical conversion of methane (CH(4)). A variety of research approaches have been taken in the experimental and theoretical fields. The main objective of this work...

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Autores principales: de Medeiros, João Paulo Fernando, da Fonseca Dias, Vitória, da Silva, José Marcelo, da Silva, Jornandes Dias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7822127/
https://www.ncbi.nlm.nih.gov/pubmed/33374497
http://dx.doi.org/10.3390/membranes11010006
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author de Medeiros, João Paulo Fernando
da Fonseca Dias, Vitória
da Silva, José Marcelo
da Silva, Jornandes Dias
author_facet de Medeiros, João Paulo Fernando
da Fonseca Dias, Vitória
da Silva, José Marcelo
da Silva, Jornandes Dias
author_sort de Medeiros, João Paulo Fernando
collection PubMed
description Pd-based membrane reformers have been substantially studied in the past as a promising reformer to produce high-purity H(2) from thermochemical conversion of methane (CH(4)). A variety of research approaches have been taken in the experimental and theoretical fields. The main objective of this work is a theoretical modelling to describe the process variables of the Steam Reforming of Methane (SRM) method on the Pd-based membrane reformer. These process variables describe the specific aims of each equation of the mathematical model characterizing the performance from reformer. The simulated results of the mole fractions of components (MFCs) at the outlet of the Fixed Bed Reformer (FBR) and Packed-Bed Membrane Reformer (PBMR) have been validated. When the H(2)O/CH(4) ratio decreases in PBMR, the Endothermic Reaction Temperature (ERT) is notably increased (998.32 K) at the outlet of the PBMR’s reaction zone. On the other hand, when the H(2)O/CH(4) ratio increases in PBMR, the ERT is remarkably decreased (827.83 K) at the outlet of the PBMR’s reaction zone. An increase of the spatial velocity (S(sp)) indicates a reduction in the residence time of reactant molecules inside PBMR and, thus, a decrease of the ERT and conversion of CH(4). In contrast, a reduction of the S(sp) shows an increase of the residence time of reactant molecules within PBMR and, therefore, a rise of the ERT and conversion of CH(4). An increase of the H(2)O/CH(4) ratio raises the conversion rate (CR) of CH(4) due to the reduction of the coke content on the catalyst particles. Conversely, a reduction of the H(2)O/CH(4) ratio decreases the CR of CH(4) owing to the increase of the coke content on the catalyst particles. Contrary to the CR of CH(4), the consumption-based yield (CBY) of H(2) sharply decreases with the increase of the H(2)O/CH(4) ratio. An increase of the ERT raises the thermochemical energy storage efficiency (η(tese)) from 68.96% (ERT = 1023 K), 63.21% (ERT = 973 K), and 48.12% (ERT = 723 K). The chemical energy, sensible heat, and heat loss reached values of 384.96 W, 151.68 W, and 249.73 W at 973 K. The selectivity of H(2) presents higher amounts in the gaseous mixture that varies from 60.98 to 73.18 while CH(4) showed lower values ranging from 1.41 to 2.06. Our work is limited to the SRM method. In terms of future uses of this method, new works can be undertaken using novel materials (open-cell foams) and the physical-mathematical model (two-dimensional and three-dimensional) to evaluate the concentration polarization inside membrane reactors.
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spelling pubmed-78221272021-01-23 Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study de Medeiros, João Paulo Fernando da Fonseca Dias, Vitória da Silva, José Marcelo da Silva, Jornandes Dias Membranes (Basel) Article Pd-based membrane reformers have been substantially studied in the past as a promising reformer to produce high-purity H(2) from thermochemical conversion of methane (CH(4)). A variety of research approaches have been taken in the experimental and theoretical fields. The main objective of this work is a theoretical modelling to describe the process variables of the Steam Reforming of Methane (SRM) method on the Pd-based membrane reformer. These process variables describe the specific aims of each equation of the mathematical model characterizing the performance from reformer. The simulated results of the mole fractions of components (MFCs) at the outlet of the Fixed Bed Reformer (FBR) and Packed-Bed Membrane Reformer (PBMR) have been validated. When the H(2)O/CH(4) ratio decreases in PBMR, the Endothermic Reaction Temperature (ERT) is notably increased (998.32 K) at the outlet of the PBMR’s reaction zone. On the other hand, when the H(2)O/CH(4) ratio increases in PBMR, the ERT is remarkably decreased (827.83 K) at the outlet of the PBMR’s reaction zone. An increase of the spatial velocity (S(sp)) indicates a reduction in the residence time of reactant molecules inside PBMR and, thus, a decrease of the ERT and conversion of CH(4). In contrast, a reduction of the S(sp) shows an increase of the residence time of reactant molecules within PBMR and, therefore, a rise of the ERT and conversion of CH(4). An increase of the H(2)O/CH(4) ratio raises the conversion rate (CR) of CH(4) due to the reduction of the coke content on the catalyst particles. Conversely, a reduction of the H(2)O/CH(4) ratio decreases the CR of CH(4) owing to the increase of the coke content on the catalyst particles. Contrary to the CR of CH(4), the consumption-based yield (CBY) of H(2) sharply decreases with the increase of the H(2)O/CH(4) ratio. An increase of the ERT raises the thermochemical energy storage efficiency (η(tese)) from 68.96% (ERT = 1023 K), 63.21% (ERT = 973 K), and 48.12% (ERT = 723 K). The chemical energy, sensible heat, and heat loss reached values of 384.96 W, 151.68 W, and 249.73 W at 973 K. The selectivity of H(2) presents higher amounts in the gaseous mixture that varies from 60.98 to 73.18 while CH(4) showed lower values ranging from 1.41 to 2.06. Our work is limited to the SRM method. In terms of future uses of this method, new works can be undertaken using novel materials (open-cell foams) and the physical-mathematical model (two-dimensional and three-dimensional) to evaluate the concentration polarization inside membrane reactors. MDPI 2020-12-23 /pmc/articles/PMC7822127/ /pubmed/33374497 http://dx.doi.org/10.3390/membranes11010006 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
de Medeiros, João Paulo Fernando
da Fonseca Dias, Vitória
da Silva, José Marcelo
da Silva, Jornandes Dias
Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study
title Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study
title_full Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study
title_fullStr Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study
title_full_unstemmed Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study
title_short Thermochemical Performance Analysis of the Steam Reforming of Methane in a Fixed Bed Membrane Reformer: A Modelling and Simulation Study
title_sort thermochemical performance analysis of the steam reforming of methane in a fixed bed membrane reformer: a modelling and simulation study
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7822127/
https://www.ncbi.nlm.nih.gov/pubmed/33374497
http://dx.doi.org/10.3390/membranes11010006
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