Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10362/8468 |
Resumo: | Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica |
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Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysisHigh-density polyethylene (HDPE)Kinetic modelingStochastic modelingThermal and catalytic degradationDifferential scanning calorimetry (DSC)Thermogravimetry (TG)Dissertação para obtenção do Grau de Mestre em Engenharia Química e BioquímicaIn the present work a stochastic model to be used for analyzing and predicting experimental data from simultaneous thermogravimetric (TG) and differential scanning calorimetry (DSC) experiments on the thermal and catalytic degradation of high-density polyethylene (HDPE) was developed. Unlike the deterministic models, already developed, with this one it’s possible to compute the mass and energy curves measured by simultaneous TG/DSC assays, as well as to predict the product distribution resulting from primary cracking of the polymer, without using any experimental information. For the stochastic model to predict the mass change as well as the energy involved in the whole process of HDPE pyrolysis, a reliable model for the cracking reaction and a set of vaporization laws suitable to compute the vaporization rates are needed. In order to understand the vaporization process, this was investigated separately from cracking. For that, a set of results from TG/DSC experiments using species that vaporize well before they crack was used to obtain a global correlation between the kinetic parameters for vaporization and the number of C-C bonds in the hydrocarbon chain. The best fitting curves were chosen based on the model ability to superimpose the experimental rates and produce consistent results for heavier hydrocarbons. The model correlations were implemented in the program’s code and allowed the prediction of the vaporization rates. For the determination of the global kinetic parameters of the degradation reaction to use in the stochastic model, a study on how these parameters influence the TG/DSC curves progress was performed varying those parameters in several simulations, comparing them with experimental data from thermal and catalytic (ZSM-5 zeolite) degradation of HDPE and choosing the best fitting. For additional improvements in the DSC stochastic model simulated curves, the thermodynamic parameters were also fitted. Additional molecular simulation studies based on quantum models were performed for a deeper understanding on the reaction mechanism and progress. The prediction of the products distribution was not the main object of the investigation in this work although preliminary results have been obtained which reveal some discrepancies in relation to the experimental data. Therefore, in future investigations, an improvement of this aspect is necessary to have a stochastic model which predicts the whole information needed to characterize HDPE degradation reaction.Faculdade de Ciências e TecnologiaLemos, FranciscoFonseca, IsabelRUNTrindade, Nuno Miguel Passarinho2013-01-08T14:57:46Z20122012-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/8468enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-03-11T03:41:05Zoai:run.unl.pt:10362/8468Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:18:12.908144Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
title |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
spellingShingle |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis Trindade, Nuno Miguel Passarinho High-density polyethylene (HDPE) Kinetic modeling Stochastic modeling Thermal and catalytic degradation Differential scanning calorimetry (DSC) Thermogravimetry (TG) |
title_short |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
title_full |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
title_fullStr |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
title_full_unstemmed |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
title_sort |
Stochastic modeling of the thermal and catalytic degradation of polyethylene using simultaneous DSC/TG analysis |
author |
Trindade, Nuno Miguel Passarinho |
author_facet |
Trindade, Nuno Miguel Passarinho |
author_role |
author |
dc.contributor.none.fl_str_mv |
Lemos, Francisco Fonseca, Isabel RUN |
dc.contributor.author.fl_str_mv |
Trindade, Nuno Miguel Passarinho |
dc.subject.por.fl_str_mv |
High-density polyethylene (HDPE) Kinetic modeling Stochastic modeling Thermal and catalytic degradation Differential scanning calorimetry (DSC) Thermogravimetry (TG) |
topic |
High-density polyethylene (HDPE) Kinetic modeling Stochastic modeling Thermal and catalytic degradation Differential scanning calorimetry (DSC) Thermogravimetry (TG) |
description |
Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012 2012-01-01T00:00:00Z 2013-01-08T14:57:46Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10362/8468 |
url |
http://hdl.handle.net/10362/8468 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Faculdade de Ciências e Tecnologia |
publisher.none.fl_str_mv |
Faculdade de Ciências e Tecnologia |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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