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Previous issue date: 2012-12-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The
activities were divided into four stages: study batch adsorption capacity of the adsorbent
with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of
gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert
closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve
of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the
adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption
studies were carried out under the following operating conditions: temperature 40 ?C
(for the pyrolysis of the sludge T = 600 ?C), pressures of 0.55 to 5.05 bar (batch
process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent
masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7
h and on the fixed bed was around 180 min. The results of this study showed that in
batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed
CO2 increases with the increases pressure, decreases with temperature increases and
rises due the increase of activation temperature adsorbent. In the batch process were
evaluated the breakthrough curves, which were compared with adsorption isotherms
represented by the models of Langmuir, Fre?ndlich and Toth. All models well adjusted
to the experimental points, but the Langmuir model was chosen in view of its use in the
dynamic model does not have implications for adsorption (indeterminacy and larger
number of parameters such as occurred with others) in solving the equation. In the fixed
bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the
maximum adsorption percentage 46.7% at 40 ?C temperature and 50 mL/min of flow
rate. The model was satisfactorily fitted to the three breakthrough curves and the
parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity
inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45
dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge
showed a fast saturation with traces of aerosols presents in the gas phase into the fixed
bed under the reaction process / O presente trabalho retrata um estudo da adsor??o de di?xido de carbono
em ze?lita comercial do tipo 13X. As atividades desenvolvidas foram divididas em
quatro etapas: estudo em batelada da capacidade de adsor??o do adsorvente com o CO2
sint?tico (4%), avalia??o din?mica em leito fixo com a mistura sint?tica de gases (4%
CO2, 1,11% CO, 1,2% H2, 0,233% CH4, 0,1% C3, 0,0233% C4 e arg?nio como inerte
fechando o balan?o), modelagem din?mica em leito fixo e avalia??o em leito fixo da
curva de ruptura do CO2 com o g?s de pir?lise do lodo de esgoto. O lodo e o adsorvente
foram caraterizados por an?lises TG/DTA, MEV, FRX e BET. Os estudos de adsor??o
foram realizados nas seguintes condi??es operat?rias: temperatura de 40 ?C (para a
pir?lise do lodo T = 600 ?C), press?o de 0,55 5,05 bar (processo batelada), vaz?o da
mistura gasosa entre 50 72 mL/min e massa de adsorvente igual a 10, 15 e 20 g
(processo em leito fixo). O tempo do processo de adsor??o em batelada foi de 7h e em
leito fixo foi em torno de 180 min. Os resultados obtidos nesta etapa mostraram que no
estudo batelada o processo de adsor??o com a ze?lita 13X ? eficiente e que a massa
adsorvida do CO2 aumenta com o crescimento da press?o, diminui com o aumento da
temperatura e se eleva com a temperatura de ativa??o do adsorvente. No processo
din?mico foram avaliadas as curvas de rupturas, as quais foram comparadas ?s
isotermas de adsor??o representadas pelos modelos de Langmuir, Fre?ndlich e Toth.
Todos os modelos se ajustaram bem aos pontos experimentais, por?m o modelo de
Langmuir foi o escolhido tendo em vista sua utiliza??o no modelo din?mico de adsor??o
n?o apresentar implica??es (indetermina??o e maior n?mero de par?metros como
ocorreu com os demais) na resolu??o da equa??o. No estudo din?mico em leito fixo
com a mistura de gases sint?ticos e diferentes massas de adsorvente, a massa de 20 g
apresentou maior percentual de adsor??o 46,7% na temperatura de 40 oC e vaz?o da
mistura gasosa de 50 mL/min. O modelo se ajustou satisfatoriamente para as tr?s curvas
de ruptura e os par?metros avaliados foram: coeficiente de dispers?o axial (0,0165
dm2/min), difusividade efetiva no interior da part?cula (0,0884 dm2/min) e coeficiente
externo de transfer?ncia de massa (0,45 dm/min). A curva de ruptura para o CO2
constru?da no processo de pir?lise do lodo mostrou uma r?pida satura??o do leito
proveniente de tra?os de aeross?is, presentes na fase gasosa, decorrentes do processo
reacional
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/15836 |
| Date | 27 December 2012 |
| Creators | Lessa, Mayara de Oliveira |
| Contributors | CPF:12270202449, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783510Y4, Pergher, Sibele Berenice Castella, CPF:50942611004, http://lattes.cnpq.br/5249001430287414, Pedroza, Marcelo Mendes, CPF:01910482404, http://lattes.cnpq.br/4401608528438096, Vieira, Gl?ucia Eliza Gama, Sousa, Jo?o Fernandes de |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Engenharia Qu?mica, UFRN, BR, Pesquisa e Desenvolvimento de Tecnologias Regionais |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| 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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