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Previous issue date: 2013-09-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Intensive use of machinery and engines burning fuel dumps into the atmosphere huge
amounts of carbon dioxide (CO2), causing the intensification of the greenhouse effect.
Climate changes that are occurring in the world are directly related to emissions of
greenhouse gases, mainly CO2, gases, mainly due to the excessive use of fossil fuels. The
search for new technologies to minimize the environmental impacts of this phenomenon has
been investigated. Sequestration of CO2 is one of the alternatives that can help minimize
greenhouse gas emissions. The CO2 can be captured by the post-combustion technology, by
adsorption using adsorbents selective for this purpose. With this objective, were synthesized
by hydrothermal method at 100 ?C, the type mesoporous materials MCM - 41 and SBA-15.
After the synthesis, the materials were submitted to a calcination step and subsequently
functionalized with different amines (APTES, MEA, DEA and PEI) through reflux method.
The samples functionalized with amines were tested for adsorption of CO2 in order to
evaluate their adsorption capacities as well, were subjected to various analyzes of
characterization in order to assess the efficiency of the method used for functionalization with
amines. The physic-chemical techniques were used: X- ray diffraction (XRD), nitrogen
adsorption and desorption (BET/BJH), scanning electron microscopy (SEM), transmission
electron microscopy (TEM), CNH Analysis, Thermogravimetry (TG/DTG) and photoelectron
spectroscopy X-ray (XPS). The CO2 adsorption experiments were carried out under the
following conditions: 100 mg of adsorbent, at 25 ?C under a flow of 100 ml/min of CO2,
atmospheric pressure and the adsorption variation in time 10-210 min. The X-ray diffraction
with the transmission electron micrographs for the samples synthesized and functionalized,
MCM-41 and SBA-15 showed characteristic peaks of hexagonal mesoporous structure
formation, showing the structure thereof was obtained. The method used was efficient reflux
according to XPS and elemental analysis, which showed the presence of amines in the starting
materials. The functionalized SBA -15 samples were those that had potential as best adsorbent
for CO2 capture when compared with samples of MCM-41, obtaining the maximum
adsorption capacity for SBA-15-P sample / A intensa utiliza??o de m?quinas e motores queimando combust?veis despeja na atmosfera
imensas quantidades de di?xido de carbono (CO2), causando a intensifica??o do Efeito Estufa.
As mudan?as clim?ticas que v?m ocorrendo no mundo est?o diretamente relacionadas ?s
emiss?es de gases de efeito estufa, principalmente CO2, devido, sobretudo, ao uso excessivo
de combust?veis f?sseis. A busca por novas tecnologias para minimizar os impactos
ambientais decorrentes deste fen?meno vem sendo investigadas. O sequestro de CO2 ? uma
das alternativas que pode ajudar a minimizar as emiss?es desses gases. O CO2 pode ser
capturado pela tecnologia p?s-combust?o, atrav?s do processo de adsor??o, utilizando
adsorventes seletivos para este fim. Com este objetivo, foram sintetizados, pelo m?todo
hidrot?rmico a 100?C, materiais mesoporosos do tipo MCM-41 e SBA-15. Ap?s as s?nteses os
materiais foram submetidos ? etapa de calcina??o e, posteriormente, funcionalizados com
diferentes tipos de aminas (APTES, MEA, DEA e PEI), atrav?s do m?todo de refluxo. As
amostras funcionalizadas com as aminas foram testadas nos ensaios de adsor??o de CO2 afim
de avaliar suas capacidades de adsor??o, bem como, foram submetidas a diversas an?lises de
caracteriza??o no intuito de avaliar a efici?ncia do m?todo utilizado para a funcionaliza??o
com as aminas. As t?cnicas f?sico-qu?micas utilizadas foram: Difra??o de Raios-X (DRX),
Adsor??o e Dessor??o de nitrog?nio (BET/BJH), Microscopia eletr?nica de varredura (MEV),
Microscopia eletr?nica de transmiss?o (MET), An?lise elementar CNH, Termogravimetria
(TG/DTG) e Espectroscopia fotoeletr?nica de Raios-X (XPS). Os ensaios de adsor??o de CO2
foram realizados nas seguintes condi??es: 100 mg de adsorvente, temperatura de 25 ?C sob
fluxo de 100 mL/min de CO2, press?o atmosf?rica e com varia??o no tempo de adsor??o de
10 a 210 min. Os difratogramas de Raios-X juntamente com as micrografias eletr?nicas de
transmiss?o para as amostras sintetizadas e funcionalizadas, MCM-41 e SBA-15,
apresentaram os picos caracter?sticos da forma??o de estrutura mesoporosa hexagonal,
evidenciando que a estrutura do mesmo foi obtida. O m?todo de refluxo utilizado foi eficiente
segundo as an?lises de elementar e XPS, na qual, mostrou a presen?a das aminas nos
materiais de partida. As amostras funcionalizadas de SBA-15 foram as que tiveram melhor
potencial como adsorvente para captura de CO2 quando comparadas com as amostras de
MCM-41, obtendo a m?xima capacidade de adsor??o para a amostra SBA-15-P
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17790 |
| Date | 30 September 2013 |
| Creators | Barbosa, Marcela Nascimento |
| Contributors | CPF:35530502415, http://lattes.cnpq.br/9770622597949866, Guedes, Ana Paula de Melo Alves, CPF:03330987499, http://lattes.cnpq.br/5738717177200782, Luz Junior, Geraldo Eduardo da, CPF:75648318391, http://lattes.cnpq.br/6484967625971729, Galv?o, Luzia Patr?cia Fernandes de Carvalho, CPF:01258619407, http://lattes.cnpq.br/4608881094150796, Fernandes J?nior, Valter Jos?, CPF:42314070453, http://lattes.cnpq.br/1595902438130772, Ara?jo, Ant?nio Souza de |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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