Síntese de zeólitas LTA para captura de CO2
Global warming is the main environmental problem faced by modern humanity and CO2 is the main gas causing this problem. For this reason, several studies have been carried out to mitigate or reduce its emission into the atmosphere. Among these researches, adsorptive processes using zeolites appear...
Na minha lista:
| Autor principal: | |
|---|---|
| Outros Autores: | |
| Formato: | Dissertação |
| Idioma: | pt_BR |
| Publicado em: |
Universidade Federal do Rio Grande do Norte
|
| Assuntos: | |
| Endereço do item: | https://repositorio.ufrn.br/handle/123456789/53021 |
| Tags: |
Adicionar Tag
Sem tags, seja o primeiro a adicionar uma tag!
|
| id |
ri-123456789-53021 |
|---|---|
| record_format |
dspace |
| institution |
Repositório Institucional |
| collection |
RI - UFRN |
| language |
pt_BR |
| topic |
Zeólita LTA Adsorção de CO2 Resíduos Seletividade Armazenamento CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA |
| spellingShingle |
Zeólita LTA Adsorção de CO2 Resíduos Seletividade Armazenamento CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA Silva, Aryandson da Síntese de zeólitas LTA para captura de CO2 |
| description |
Global warming is the main environmental problem faced by modern humanity and CO2
is the main gas causing this problem. For this reason, several studies have been carried
out to mitigate or reduce its emission into the atmosphere. Among these researches,
adsorptive processes using zeolites appear as a possibility to minimize this problem. In
this work, LTA zeolites using three different silicon sources were synthesized to be
applied in CO2 adsorption, namely, LIASA industrial waste, light coal ash waste and
aerosill 200 silica. exchange the sodium present in its structure for calcium being applied
in the adsorption of CO2 at room temperature (23°C) up to 7500 mmHg, and at 200°C
from 3750 mmHg to 18750 mmHg. N2 adsorption tests were also carried out under the
same conditions as CO2 and adsorption with a CO2/CH4 gas mixture in a fixed bed to
calculate adsorption selectivity. Finally, the analysis of adsorption cycles was carried out
under room temperature conditions (23 °C) up to 7500 mmHg. X-ray diffraction analysis
(XRD) and scanning electron microscopy (SEM) indicated that the LTA zeolite was
obtained from all the raw materials used, however, with different crystallinities. The
analyzes of argon adsorption/desorption, at 77K, demonstrated that the cationic exchange
was carried out and, the LTA zeolites in the calcic form, were obtained, being evidenced
by the increase of the specific area, volume of pores and volume of micropores. The
materials used showed good adsorption capacity for CO2, ranging between 2.64 mmol/g
and 4.25 mmol/g at 7500 mmHg, with the standard and commercial materials obtaining
the best results, the materials obtained from coal ash, exhibited the lowest adsorption
capacity, whereas the zeolite synthesized by the LIASA residue showed an adsorption
capacity close to standard zeolite and commercial zeolite. After ion exchange, the amount
adsorbed by all materials increased considerably, maintaining the order of adsorbed
amount, ranging from 2.55 mmol/g to 5.39 mmol/g at 7500 mmHg. When comparing
with the models of Langmuir, Freündlich and Temkin, it was seen that all of them
presented a greater approximation with the model of Temkin, characterizing a primarily
physical adsorption in the material. When analyzing the isotherms under the most extreme
conditions, we see that the material also has a good adsorption capacity, and with
increasing pressure, the amount adsorbed continues to increase even at higher
temperatures. Analyzing the selectivity of the materials for CO2 and N2, we see that the
material synthesized from waste showed greater selectivity both in the sodium form with
5.04 mmolCO2/mmolN2 at 7500 mmHg, and in the calcium form with selectivity equal
to 3.90 mmolCO2 /mmolN2 at 7500 mmHg, which may mean that, due to its lower
crystallinity, part of its porous structure has defects that prevent greater diffusion of N2
compared to CO2. A good selectivity was also observed in the adsorption in a fixed bed
with a CO2/CH4 gas mixture, where it is possible to see that the material has selectivity
to CO2, however, in this case, the commercial zeolite with calcium presented the best
results of adsorption and selectivity, presenting a total selectivity equal to 4.39
mmolCO2/mmolCH4. In the adsorption cycles, it is noticed that all materials show a
small decrease from the second cycle onwards and after five cycles, the greatest reduction
was 0.34 mmol/g for the standard zeolite, which may be related to some process of
chemisorption going on in the material, as the material has not been fully regenerated
with a high vacuum for one hour. |
| author2 |
Pergher, Sibele Berenice Castella |
| author_facet |
Pergher, Sibele Berenice Castella Silva, Aryandson da |
| format |
masterThesis |
| author |
Silva, Aryandson da |
| author_sort |
Silva, Aryandson da |
| title |
Síntese de zeólitas LTA para captura de CO2 |
| title_short |
Síntese de zeólitas LTA para captura de CO2 |
| title_full |
Síntese de zeólitas LTA para captura de CO2 |
| title_fullStr |
Síntese de zeólitas LTA para captura de CO2 |
| title_full_unstemmed |
Síntese de zeólitas LTA para captura de CO2 |
| title_sort |
síntese de zeólitas lta para captura de co2 |
| publisher |
Universidade Federal do Rio Grande do Norte |
| publishDate |
2023 |
| url |
https://repositorio.ufrn.br/handle/123456789/53021 |
| work_keys_str_mv |
AT silvaaryandsonda sintesedezeolitasltaparacapturadeco2 |
| _version_ |
1773962766749532160 |
| spelling |
ri-123456789-530212023-07-04T20:11:30Z Síntese de zeólitas LTA para captura de CO2 Silva, Aryandson da Pergher, Sibele Berenice Castella http://lattes.cnpq.br/1020886698632089 http://lattes.cnpq.br/5249001430287414 Mello, Mariele Iara Soares de https://orcid.org/0000-0002-5979-2474 http://lattes.cnpq.br/8225162650698181 Loiola, Adonay Rodrigues Penha, Fábio Garcia Santos, Luciene da Silva Zeólita LTA Adsorção de CO2 Resíduos Seletividade Armazenamento CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA Global warming is the main environmental problem faced by modern humanity and CO2 is the main gas causing this problem. For this reason, several studies have been carried out to mitigate or reduce its emission into the atmosphere. Among these researches, adsorptive processes using zeolites appear as a possibility to minimize this problem. In this work, LTA zeolites using three different silicon sources were synthesized to be applied in CO2 adsorption, namely, LIASA industrial waste, light coal ash waste and aerosill 200 silica. exchange the sodium present in its structure for calcium being applied in the adsorption of CO2 at room temperature (23°C) up to 7500 mmHg, and at 200°C from 3750 mmHg to 18750 mmHg. N2 adsorption tests were also carried out under the same conditions as CO2 and adsorption with a CO2/CH4 gas mixture in a fixed bed to calculate adsorption selectivity. Finally, the analysis of adsorption cycles was carried out under room temperature conditions (23 °C) up to 7500 mmHg. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) indicated that the LTA zeolite was obtained from all the raw materials used, however, with different crystallinities. The analyzes of argon adsorption/desorption, at 77K, demonstrated that the cationic exchange was carried out and, the LTA zeolites in the calcic form, were obtained, being evidenced by the increase of the specific area, volume of pores and volume of micropores. The materials used showed good adsorption capacity for CO2, ranging between 2.64 mmol/g and 4.25 mmol/g at 7500 mmHg, with the standard and commercial materials obtaining the best results, the materials obtained from coal ash, exhibited the lowest adsorption capacity, whereas the zeolite synthesized by the LIASA residue showed an adsorption capacity close to standard zeolite and commercial zeolite. After ion exchange, the amount adsorbed by all materials increased considerably, maintaining the order of adsorbed amount, ranging from 2.55 mmol/g to 5.39 mmol/g at 7500 mmHg. When comparing with the models of Langmuir, Freündlich and Temkin, it was seen that all of them presented a greater approximation with the model of Temkin, characterizing a primarily physical adsorption in the material. When analyzing the isotherms under the most extreme conditions, we see that the material also has a good adsorption capacity, and with increasing pressure, the amount adsorbed continues to increase even at higher temperatures. Analyzing the selectivity of the materials for CO2 and N2, we see that the material synthesized from waste showed greater selectivity both in the sodium form with 5.04 mmolCO2/mmolN2 at 7500 mmHg, and in the calcium form with selectivity equal to 3.90 mmolCO2 /mmolN2 at 7500 mmHg, which may mean that, due to its lower crystallinity, part of its porous structure has defects that prevent greater diffusion of N2 compared to CO2. A good selectivity was also observed in the adsorption in a fixed bed with a CO2/CH4 gas mixture, where it is possible to see that the material has selectivity to CO2, however, in this case, the commercial zeolite with calcium presented the best results of adsorption and selectivity, presenting a total selectivity equal to 4.39 mmolCO2/mmolCH4. In the adsorption cycles, it is noticed that all materials show a small decrease from the second cycle onwards and after five cycles, the greatest reduction was 0.34 mmol/g for the standard zeolite, which may be related to some process of chemisorption going on in the material, as the material has not been fully regenerated with a high vacuum for one hour. Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq O aquecimento global é o principal problema ambiental enfrentado pela humanidade moderna e o CO2 é o principal gás causador desse problema. Por esse motivo, diversas pesquisas vêm sendo realizadas para mitigar ou diminuir sua emissão para a atmosfera. Dentre essas pesquisas os processos adsortivos utilizando zeólitas aparecem como uma possibilidade de minimização desse problema. Neste trabalho, zeólitas LTA usando três fontes de silício diferentes foram sintetizadas para serem aplicadas na adsorção de CO2, sendo elas, o resíduo industrial LIASA, o resíduo cinzas leve de carvão e sílica aerosill 200. Esses materiais passaram por processos de troca catiônica, para trocar o sódio presente na sua estrutura por cálcio sendo aplicados na adsorção de CO2 em temperatura ambiente (23 °C) até 7500 mmHg, e em 200°C de 3750 mmHg até 18750 mmHg. Foram também realizados testes de adsorção de N2 nas mesmas condições do CO2 e adsorção com mistura gasosa CO2/CH4 em leito fixo para calcular seletividade de adsorção. Por último foi realizado a análise de ciclos de adsorção nas condições de temperatura ambiente (23 °C) até 7500 mmHg. Análises de difração de raios X (DRX) e microscopia eletrônica de varredura (MEV), indicaram que a zeólita LTA foi obtida a partir de todas as matérias primas utilizadas, porém, com cristalinidades diferentes. As análises de adsorção/dessorção de argônio, a 77K, demonstraram que a troca catiônica foi realizada e, as zeólitas LTA na forma cálcica, foram obtidas, sendo evidenciado pelo aumento da área específica, volume de poros e volume de microporos. Os materiais utilizados apresentaram boa capacidade de adsorção para CO2, variando entre 2,64 mmol/g e 4,25 mmol/g em 7500 mmHg, sendo os materiais padrões e comercial obtendo os melhores resultados, os materiais obtidos a partir de cinzas de carvão, exibiram a menor capacidade de adsorção, já a zeólita sintetizada pelo resíduo LIASA apresentou uma capacidade de adsorção próxima da zeólita padrão e da zeólita comercial. Após a troca iônica, a quantidade adsorvida por todos os materiais aumentou, consideravelmente, mantendo a ordem de quantidade adsorvida, variando de 2,55 mmol/g e 5,39 mmol/g em 7500 mmHg. Ao comparar com os modelos de Langmuir, Freündlich e Temkin, foi visto que todos apresentaram uma aproximação maior com o modelo de Temkin, caracterizando uma adsorção prioritariamente física no material. Ao analisar as isotermas nas condições mais extremas, vemos que o material também possui uma boa capacidade de adsorção, e com o aumento da pressão, ainda continua aumentando a quantidade adsorvida mesmo em temperaturas mais elevadas. Analisando a seletividade dos materiais por CO2 e N2, vemos que o material sintetizado a partir de resíduo apresentou uma maior seletividade tanto na forma sódica com 5,04 mmolCO2/mmolN2 em 7500 mmHg, quanto na forma cálcica com seletividade igual a 3,90 mmolCO2/mmolN2 em 7500 mmHg, o que pode significar que, por possuir uma menor cristalinidade, parte de sua estrutura porosa possui defeitos que impedem uma maior difusão do N2 em comparação com o CO2. Também foi observado uma boa seletividade na adsorção em leito fixo com mistura gasosa CO2/CH4, onde é possível ver que o material tem seletividade ao CO2, porém, nesse caso, a zeólita comercial com cálcio apresentou os melhores resultados de adsorção e seletividade apresentando uma seletividade total igual a 4,39 mmolCO2/mmolCH4. Nos ciclos de adsorção, percebe-se que todos os materiais apresentam uma pequena diminuição a partir do segundo ciclo e após cinco ciclos, a maior redução foi de 0,34 mmol/g para a zeólita padrão, o que pode estar relacionado com algum processo de quimissorção que esteja acontecendo no material, já que o material não foi totalmente regenerado com um alto vácuo durante uma hora. 2023-07-04T20:10:42Z 2023-07-04T20:10:42Z 2023-02-27 masterThesis SILVA, Aryandson da. Síntese de zeólitas LTA para captura de CO2. Orientador: Sibele Berenice Castella Pergher. 2023. 133f. Dissertação (Mestrado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2023. https://repositorio.ufrn.br/handle/123456789/53021 pt_BR Acesso Aberto application/pdf Universidade Federal do Rio Grande do Norte Brasil UFRN PROGRAMA DE PÓS-GRADUAÇÃO EM QUÍMICA |