(Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa

Detalhes bibliográficos
Autor(a) principal: Castro, Antônio Joel Ramiro de
Data de Publicação: 2013
Tipo de documento: Dissertação
Idioma: por
Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
dARK ID: ark:/83112/001300001s594
Texto Completo: http://www.repositorio.ufc.br/handle/riufc/13880
Resumo: Currently, biomass has been used as renewable source for energy generation through the combustion process and also for producing biochars and biofuels. In this study, it has been reported an alternative use of biomass to produce new carbonaceous materials aiming to understand their properties to search new applications. The obtained nanomaterials were produced through sustainability approaches. This way, hydrothermal carbonization method (HTC) was used to prepare the nanomaterials, in which chitosan was applied as precursor. Distinct preparations of the nanomaterials (hydrothermal carbon) by varying the carbonization time and temperature were achieved. The nanomaterials were characterized to evaluate their structural, morphological, compositional and textural features. Typical low structural ordering of amorphous carbon was observed for the hydrothermal carbons. Compositional results have shown that the carbon contents increased with increasing both time and temperature of carbonization, reaching carbon amounts up to 55 %. Nitrogen contents varied from 5 to 6 %, independently of the reaction parameters, on the other hand. Additionally, hydroxyl, amines and amides functional groups remained or were produced on solid surfaces. Irregular plate-like morphologies possessing aggregated nanoparticles in micrometer range were observed over the hydrothermal carbons. Indeed, they had surface areas values in the 60-290 m2/g range, depending on the synthesis parameter established. Besides, both chitosan and hydrothermal carbons were pyrolysed in order to compare their aforesaid features. Pyrolysis of the hydrothermal carbons resulted in a defective graphitic-type structure formation. For hydrothermal carbon pyrolysis, the carbon amounts increased with the temperature increments, in accordance with the FTIR results, suggesting a loss of the abovementioned functional groups. After treating the solid with different temperatures, about 7 % of nitrogen was included into the solid structure and it results in a nitrogen-doped carbonaceous material. Hydrothermal carbon pyrolysed at 600 ◦C displayed a product with surface area around 420 m2/g, being seven times higher than that of the precursor counterparts. Although the morphology of the particles was not strongly affected, surface macropores were observed. By increasing the temperature of the pyrolysis process, the direct pyrolysed chitosan exhibited also a graphitic-type structure formation and this structure is originated from a low ordering intermediate. Due to the materials volatilization loss during the chitosan pyrolysis, the conversion of carbon was lesser than 100 %. When pyrolysis was achieved at 300 ◦C, surface area of the solids was 82 m2/g and the textural parameters dropped to values close to zero, indicating a non-porous solid up to 300 ◦C. The features of the nanomaterials produced in this work enable them to act as catalysts supports, new adsorbents and showing promise in agriculture fields as well.
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spelling (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassaBiomassaCarbonizaçãoSustentabilidadeCarbonoCurrently, biomass has been used as renewable source for energy generation through the combustion process and also for producing biochars and biofuels. In this study, it has been reported an alternative use of biomass to produce new carbonaceous materials aiming to understand their properties to search new applications. The obtained nanomaterials were produced through sustainability approaches. This way, hydrothermal carbonization method (HTC) was used to prepare the nanomaterials, in which chitosan was applied as precursor. Distinct preparations of the nanomaterials (hydrothermal carbon) by varying the carbonization time and temperature were achieved. The nanomaterials were characterized to evaluate their structural, morphological, compositional and textural features. Typical low structural ordering of amorphous carbon was observed for the hydrothermal carbons. Compositional results have shown that the carbon contents increased with increasing both time and temperature of carbonization, reaching carbon amounts up to 55 %. Nitrogen contents varied from 5 to 6 %, independently of the reaction parameters, on the other hand. Additionally, hydroxyl, amines and amides functional groups remained or were produced on solid surfaces. Irregular plate-like morphologies possessing aggregated nanoparticles in micrometer range were observed over the hydrothermal carbons. Indeed, they had surface areas values in the 60-290 m2/g range, depending on the synthesis parameter established. Besides, both chitosan and hydrothermal carbons were pyrolysed in order to compare their aforesaid features. Pyrolysis of the hydrothermal carbons resulted in a defective graphitic-type structure formation. For hydrothermal carbon pyrolysis, the carbon amounts increased with the temperature increments, in accordance with the FTIR results, suggesting a loss of the abovementioned functional groups. After treating the solid with different temperatures, about 7 % of nitrogen was included into the solid structure and it results in a nitrogen-doped carbonaceous material. Hydrothermal carbon pyrolysed at 600 ◦C displayed a product with surface area around 420 m2/g, being seven times higher than that of the precursor counterparts. Although the morphology of the particles was not strongly affected, surface macropores were observed. By increasing the temperature of the pyrolysis process, the direct pyrolysed chitosan exhibited also a graphitic-type structure formation and this structure is originated from a low ordering intermediate. Due to the materials volatilization loss during the chitosan pyrolysis, the conversion of carbon was lesser than 100 %. When pyrolysis was achieved at 300 ◦C, surface area of the solids was 82 m2/g and the textural parameters dropped to values close to zero, indicating a non-porous solid up to 300 ◦C. The features of the nanomaterials produced in this work enable them to act as catalysts supports, new adsorbents and showing promise in agriculture fields as well.Atualmente a biomassa tem sido utilizada como fonte renovável para a geração de energia, através de sua combustão, e para a produção de carvão e biocombustíveis. Esta Dissertação tem como proposta o aproveitamento alternativo de biomassa para a produção de novos materiais carbonáceos, buscando entender suas propriedades e, desta forma, vislumbrar novas aplicações. A obtenção destes (nano)materiais foi realizada dentro dos conceitos da produção sustentável de materiais. Desta forma, utilizou-se a metodologia de carbonização hidrotérmica (HTC) e resíduos da biomassa (quitosana) como fonte precursora para a preparação dos (nano)materiais. Os (nano)materiais obtidos (carbono hidrotérmico) a partir das diferentes preparações, variando-se o tempo e a temperatura da carbonização, foram caracterizados quanto à sua estrutura, morfologia, composição e textura. Os diferentes carbonos hidrotérmicos preparados apresentaram baixo ordenamento estrutural, característico de carbono amorfo. Em relação à composição, os teores de carbono aumentam com a elevação do tempo e da temperatura atingindo um patamar em aproximadamente 55 %. Por outro lado, os teores de nitrogênio permanecem entre 5 e 6 %, independente dos parâmetros de preparação. Adicionalmente, grupos funcionais hidroxila, ácidos carboxílicos, aminas e amidas ainda permanecem ou são gerados em na superfície do material. Os carbonos hidrotérmicos apresentam partículas da ordem de mícrons com morfologia de placas irregulares constituídas de agregados de nanopartículas e possuem áreas superficiais no intervalo de 60-290 m2/g, dependendo dos parâmetros de síntese. Além disso, a quitosana e o carbono hidrotérmico foram pirolisados visando compará-los do ponto de vista estrutural, composicional, morfológico e textural. A pirólise do carbono hidrotérmico promoveu a formação de uma estrutura do tipo grafítica, porém muito defeituosa. A porcentagem em carbono dos produtos aumentou com o incremento da temperatura de pirólise, corroborando com os resultados de FTIR, nos quais sugerem a perda dos grupos funcionais. Aproximadamente 7 % de nitrogênio continuam inseridos na estrutura após o tratamento térmico, gerando, desta forma, um material carbonáceo dopado com nitrogênio. A pirólise do carbono hidrotérmico a 600 oC levou a um produto com área superficial de aproximadamente 420 m2/g sendo sete vezes maior que a área de seu precursor. A morfologia das partículas não foi drasticamente modificada, porém observa-se a formação macroporos. Na pirólise direta da quitosana, o aumento da temperatura também acarreta na formação de uma estrutura do tipo grafítica, passando por um intermediário de baixo ordenamento estrutural. A conversão em carbono não foi de 100 %, uma vez que se observou perda de material por volatilização durante as reações. A área superficial foi de 82 m2/g quando a pirólise foi realizada a 300 oC e aproximadamente nula para maiores temperaturas. Dadas às características dos nanomateriais produzidos estes poderão ser aplicados como suporte para catalisadores, novos adsorventes e em agricultura.Ferreira, Odair PastorCastro, Antônio Joel Ramiro de2015-11-03T19:47:09Z2015-11-03T19:47:09Z2013info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfCASTRO, A. J. R. (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa. 2013. 108 f. Dissertação (Mestrado em Física) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2013.http://www.repositorio.ufc.br/handle/riufc/13880ark:/83112/001300001s594porreponame:Repositório Institucional da Universidade Federal do Ceará (UFC)instname:Universidade Federal do Ceará (UFC)instacron:UFCinfo:eu-repo/semantics/openAccess2019-07-17T19:22:00Zoai:repositorio.ufc.br:riufc/13880Repositório InstitucionalPUBhttp://www.repositorio.ufc.br/ri-oai/requestbu@ufc.br || repositorio@ufc.bropendoar:2024-09-11T18:52:25.677461Repositório Institucional da Universidade Federal do Ceará (UFC) - Universidade Federal do Ceará (UFC)false
dc.title.none.fl_str_mv (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
title (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
spellingShingle (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
Castro, Antônio Joel Ramiro de
Biomassa
Carbonização
Sustentabilidade
Carbono
title_short (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
title_full (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
title_fullStr (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
title_full_unstemmed (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
title_sort (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa
author Castro, Antônio Joel Ramiro de
author_facet Castro, Antônio Joel Ramiro de
author_role author
dc.contributor.none.fl_str_mv Ferreira, Odair Pastor
dc.contributor.author.fl_str_mv Castro, Antônio Joel Ramiro de
dc.subject.por.fl_str_mv Biomassa
Carbonização
Sustentabilidade
Carbono
topic Biomassa
Carbonização
Sustentabilidade
Carbono
description Currently, biomass has been used as renewable source for energy generation through the combustion process and also for producing biochars and biofuels. In this study, it has been reported an alternative use of biomass to produce new carbonaceous materials aiming to understand their properties to search new applications. The obtained nanomaterials were produced through sustainability approaches. This way, hydrothermal carbonization method (HTC) was used to prepare the nanomaterials, in which chitosan was applied as precursor. Distinct preparations of the nanomaterials (hydrothermal carbon) by varying the carbonization time and temperature were achieved. The nanomaterials were characterized to evaluate their structural, morphological, compositional and textural features. Typical low structural ordering of amorphous carbon was observed for the hydrothermal carbons. Compositional results have shown that the carbon contents increased with increasing both time and temperature of carbonization, reaching carbon amounts up to 55 %. Nitrogen contents varied from 5 to 6 %, independently of the reaction parameters, on the other hand. Additionally, hydroxyl, amines and amides functional groups remained or were produced on solid surfaces. Irregular plate-like morphologies possessing aggregated nanoparticles in micrometer range were observed over the hydrothermal carbons. Indeed, they had surface areas values in the 60-290 m2/g range, depending on the synthesis parameter established. Besides, both chitosan and hydrothermal carbons were pyrolysed in order to compare their aforesaid features. Pyrolysis of the hydrothermal carbons resulted in a defective graphitic-type structure formation. For hydrothermal carbon pyrolysis, the carbon amounts increased with the temperature increments, in accordance with the FTIR results, suggesting a loss of the abovementioned functional groups. After treating the solid with different temperatures, about 7 % of nitrogen was included into the solid structure and it results in a nitrogen-doped carbonaceous material. Hydrothermal carbon pyrolysed at 600 ◦C displayed a product with surface area around 420 m2/g, being seven times higher than that of the precursor counterparts. Although the morphology of the particles was not strongly affected, surface macropores were observed. By increasing the temperature of the pyrolysis process, the direct pyrolysed chitosan exhibited also a graphitic-type structure formation and this structure is originated from a low ordering intermediate. Due to the materials volatilization loss during the chitosan pyrolysis, the conversion of carbon was lesser than 100 %. When pyrolysis was achieved at 300 ◦C, surface area of the solids was 82 m2/g and the textural parameters dropped to values close to zero, indicating a non-porous solid up to 300 ◦C. The features of the nanomaterials produced in this work enable them to act as catalysts supports, new adsorbents and showing promise in agriculture fields as well.
publishDate 2013
dc.date.none.fl_str_mv 2013
2015-11-03T19:47:09Z
2015-11-03T19:47:09Z
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 CASTRO, A. J. R. (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa. 2013. 108 f. Dissertação (Mestrado em Física) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2013.
http://www.repositorio.ufc.br/handle/riufc/13880
dc.identifier.dark.fl_str_mv ark:/83112/001300001s594
identifier_str_mv CASTRO, A. J. R. (Nano)Materiais à base de carbono e nitrogênio obtidos a partir da carbonização hidrotérmica de biomassa. 2013. 108 f. Dissertação (Mestrado em Física) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2013.
ark:/83112/001300001s594
url http://www.repositorio.ufc.br/handle/riufc/13880
dc.language.iso.fl_str_mv por
language por
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.source.none.fl_str_mv reponame:Repositório Institucional da Universidade Federal do Ceará (UFC)
instname:Universidade Federal do Ceará (UFC)
instacron:UFC
instname_str Universidade Federal do Ceará (UFC)
instacron_str UFC
institution UFC
reponame_str Repositório Institucional da Universidade Federal do Ceará (UFC)
collection Repositório Institucional da Universidade Federal do Ceará (UFC)
repository.name.fl_str_mv Repositório Institucional da Universidade Federal do Ceará (UFC) - Universidade Federal do Ceará (UFC)
repository.mail.fl_str_mv bu@ufc.br || repositorio@ufc.br
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