A carregar...
Publicação
Design of Chitin/Chitosan based material for CO2 capture
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 3.3 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
A procura por soluções de combate à poluição tem sido cada vez maior. Seja a nível marí-timo, terrestre ou atmosférico, a poluição tem vindo a desempenhar um papel negativo na vida dos seres vivos. O avanço tecnológico e científico permite-nos explorar caminhos nunca imagi-náveis, mas além dos inúmeros benefícios também nos traz problemas ambientais, como o cres-cimento das emissões de CO2 e o consequente aumento da temperatura terrestre.
Apesar de serem utilizadas algumas medidas que têm a intenção de reduzir a quantidade de CO2 emitida pelas unidades fabris, como é o caso das soluções aquosas de aminas, estas não são sustentáveis a nível energético e ambiental, devido a formação de produtos corrosivos e difi-culdade na regeneração do material. Neste sentido, esta dissertação tem como objectivo a busca de uma solução para um dos maiores problemas actuais: o aumento da quantidade de CO2 na atmosfera. Como tal, o uso de materiais baseados em líquidos iónicos (LIs) é uma maneira de reduzir o custo ambiental, devido sua estabilidade e capacidade de reuso, e o uso de biopolímeros, tal como a quitina, possibilita a redução do custo económico.
Neste trabalho a dissolução dos biopolímeros, nomeadamente quitina e quitosano, em lí-quidos iónicos foi realizada para a criação de um material capaz de capturar CO2 em condições temperatura e pressão ambiente (1 atm, 25ºC). O uso da técnica de RMN de 13C permitiu avaliar a capacidade quantitativa de captura. Outras técnicas como MOLP, TGA, FTIR foram utilizadas na caracterização do material.
Diferentes estruturas de catiões e aniões foram testadas obtendo-se resultados significativos foram obtidos no caso dos materiais desenvolvidos com acetado de colina, onde se obteve uma capacidade máxima de 0,41 mol CO2 /mol LI. Além disso, cálculos de viabilidade económica foram realizados a fim de avaliar a possibilidade da substituição das aminas a nível industrial por materiais baseados em líquidos iónicos e biopolímeros, possibilitando assim um avanço tecnoló-gico no controle do aquecimento global.
The demand for pollution-fighting solutions has increased. Whether at sea, land or at-mospheric level, pollution has been playing a negative role in the lifes of living beings. Techno-logical and scientific advances allow us to explore paths never imaginable, despite of the count-less benefits, it also brings environmental problems, such as the growth of CO2 emissions and the consequent increase in Earth temperature. Although some measures are used that are intended to reduce the amount of CO2 expelled by the manufacturing units, as is the case of aqueous solutions of amines, these are not sustainable in energy and environmental, due to the formation of corrosive products and difficulty in the regeneration of the material. In this sense, this dissertation aims to search for a solution to one of the current problems: the increase in the amount of CO2 in the atmosphere. As such, the use of ionic liquid-based materials (ILs) is a way to reduce the ambiental cost due to their stability and reuse capacity, and the use of biopolymers, such as chitin, bring the advantage of reducing eco-nomic cost. In this work, the dissolution of biopolymers, namely chitin and chitosan, in ionic liquids was carried out to create a material able to capture CO2 under environmental conditions of tem-perature and pressure (1 atm, 25ºC). The use of the 13C NMR technique allowed the evaluation of the quantitative capture capacity. Other techniques such as POM, TGA, FTIR were used in the characterization of the materials. Different cation and anion structures were tested, and significant results were obtained especially in the case of materials with choline acetate, obtaining a maximum capacity of 0,41 molCO2/ molLI. In addition, economic feasibility calculations were proceeded to evaluate the possibility of replacing industrial amines with materials based on ionic liquids and biopolymers, thus enabling a technological advance in the control of global warming.
The demand for pollution-fighting solutions has increased. Whether at sea, land or at-mospheric level, pollution has been playing a negative role in the lifes of living beings. Techno-logical and scientific advances allow us to explore paths never imaginable, despite of the count-less benefits, it also brings environmental problems, such as the growth of CO2 emissions and the consequent increase in Earth temperature. Although some measures are used that are intended to reduce the amount of CO2 expelled by the manufacturing units, as is the case of aqueous solutions of amines, these are not sustainable in energy and environmental, due to the formation of corrosive products and difficulty in the regeneration of the material. In this sense, this dissertation aims to search for a solution to one of the current problems: the increase in the amount of CO2 in the atmosphere. As such, the use of ionic liquid-based materials (ILs) is a way to reduce the ambiental cost due to their stability and reuse capacity, and the use of biopolymers, such as chitin, bring the advantage of reducing eco-nomic cost. In this work, the dissolution of biopolymers, namely chitin and chitosan, in ionic liquids was carried out to create a material able to capture CO2 under environmental conditions of tem-perature and pressure (1 atm, 25ºC). The use of the 13C NMR technique allowed the evaluation of the quantitative capture capacity. Other techniques such as POM, TGA, FTIR were used in the characterization of the materials. Different cation and anion structures were tested, and significant results were obtained especially in the case of materials with choline acetate, obtaining a maximum capacity of 0,41 molCO2/ molLI. In addition, economic feasibility calculations were proceeded to evaluate the possibility of replacing industrial amines with materials based on ionic liquids and biopolymers, thus enabling a technological advance in the control of global warming.
Descrição
Palavras-chave
Líquidos iónicos Biopolímeros Captura de CO2 Quitina Quitosano Ressonância Magnética Nuclear