A carregar...
Publicação
Topical IL@MOF-based (ad)sorbents for Gas Separation
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 2.48 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
De ano para ano as emissões de gases com efeito de estufa aumentam. O CO2 é emitido para a atmosfera a partir da combustão de combustíveis fósseis e, a longo prazo, origina problemas ambi-entais, energéticos e económicos. O seu impacto nas alterações climáticas é elevado, sendo muito importante pesquisar novas formas de mitigação ambiental.
No âmbito desta dissertação foram produzidos seis compósitos de IL@MOF com diferentes per-centagens de IL (15 e 30%) no ZIF-8, e os seus respetivos carvões. Os novos materiais foram carac-terizados através de analise elementar, FT-IR, TGA, PXRD e picnometria de hélio. Além disso foram analisadas as capacidades de adsorção e seletividade dos gases (CO2, CH4 e N2).
Os resultados de equilíbrio de adsorção mostram que o compósito de 15% de [C6MIM][B(CN)4]@ZIF-8 apresenta boa capacidade de adsorção. No caso dos carvões, o mesmo é observado para o carvão com 15% de [C6MIM][N(CN)2]@ZIF-8.
O estudo da seletividade ideal de CO2/CH4 e CO2/N2 nos vários compósitos apresenta resultados bastante promissores. A seletividade ideal de CO2/CH4 e CO2/N2 para os compósitos e respetivos car-vões varia bastante nas diferentes gamas de pressão estudadas. O carvão de compósito de 30% de [C6MIM][B(CN)4]@ZIF-8 apresenta resultados muito altos a baixa pressão (até 1 bar). Adicionalmente os compósitos de 30% de [C6MIM][N(CN)2]@ZIF-8 e de [C6MIM][C(CN)3]@ZIF-8 mostram boa seletivi-dade a pressões mais altas (1-10 bar).
Em suma, o estudo proporciona um contributo importante na área de adsorção e seletividade gasosa e oferece oportunidades para a investigação futura dos compósitos e os seus respetivos car-vões.
Year after year greenhouse gas emissions increase. CO2 is emitted into the atmosphere from the combustion of fossil fuels and, in the long term, causes environmental, energetic and economic prob-lems. There is a high impact on climate change and it is very important to search for new ways of environmental mitigation. In this dissertation, six IL@MOF composites with different percentages of IL (15 and 30%) were produced at ZIF-8, and their respective carbons. The new materials were characterized through ele-mental analysis, FT-IR, TGA, PXRD and helium pycnometry. In addition, the adsorption capacities and selectivity of gases (CO2, CH4 and N2) were analyzed. The results of adsorption equilibrium show that the 15% composite of [C6MIM][B(CN)4]@ZIF-8 presents good adsorption capacities. In the case of carbons, the same is observed with 15% of [C6MIM][N(CN)2]@ZIF-8. The study of the ideal selectivity of CO2/CH4 and CO2/N2 in several composites shows very prom-ising results. The ideal selectivity of CO2/CH4 and CO2/N2 in the composites and carbons varies signifi-cantly in the different pressure ranges studied. The 30% composite carbon [C6MIM][B(CN)4]@ZIF-8 shows very high results at low pressures (up to 1 bar). Moreover, 30% composites of [C6MIM][N(CN)2]@ZIF-8 and [C6MIM][C(CN)3]@ZIF-8 show good selectivities at higher pressures (1-10 bar). To sum up, the study provides an important contribution in the area of gas adsorption and selec-tivity and offers opportunities for future researches of composites and their respective carbons.
Year after year greenhouse gas emissions increase. CO2 is emitted into the atmosphere from the combustion of fossil fuels and, in the long term, causes environmental, energetic and economic prob-lems. There is a high impact on climate change and it is very important to search for new ways of environmental mitigation. In this dissertation, six IL@MOF composites with different percentages of IL (15 and 30%) were produced at ZIF-8, and their respective carbons. The new materials were characterized through ele-mental analysis, FT-IR, TGA, PXRD and helium pycnometry. In addition, the adsorption capacities and selectivity of gases (CO2, CH4 and N2) were analyzed. The results of adsorption equilibrium show that the 15% composite of [C6MIM][B(CN)4]@ZIF-8 presents good adsorption capacities. In the case of carbons, the same is observed with 15% of [C6MIM][N(CN)2]@ZIF-8. The study of the ideal selectivity of CO2/CH4 and CO2/N2 in several composites shows very prom-ising results. The ideal selectivity of CO2/CH4 and CO2/N2 in the composites and carbons varies signifi-cantly in the different pressure ranges studied. The 30% composite carbon [C6MIM][B(CN)4]@ZIF-8 shows very high results at low pressures (up to 1 bar). Moreover, 30% composites of [C6MIM][N(CN)2]@ZIF-8 and [C6MIM][C(CN)3]@ZIF-8 show good selectivities at higher pressures (1-10 bar). To sum up, the study provides an important contribution in the area of gas adsorption and selec-tivity and offers opportunities for future researches of composites and their respective carbons.
Descrição
Palavras-chave
adsorção separação de CO2 líquidos iónicos MOFs carvões derivados de MOF