Extração e caracterização de fibras de celulose a partir de resíduos agroindustriais dentro do conceito de biorrefinaria: estudo preliminar
Data
2020-10-14
Autores
Silva, Laiana Tamion da 
Orientadores
Tovar, Laura Plazas
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O cenário brasileiro faz com que a casca de arroz seja selecionada como um
potencial atrativo para compor o “Cluster” de processos, capaz de produzir alimentos
à bioenergia, biocombustíveis, bioprodutos, intermediários petroquímicos
farmacêuticos e materiais biodegradáveis e renováveis. Este estudo objetivou isolar
as fibras de celulose da matriz lignocelulósica da casca de arroz acoplando as
seguintes etapas de biorrefino: hidrólise ácida diluída, tratamento alcalino e
branqueamento. As fibras de celulose extraídas da casca de arroz foram examinadas
em função da sua composição polimérica (~83%). Entretanto, ainda possui um teor
de lignina e cinzas de ~8,7 e ~5,0%, respectivamente. Os resultados da análise
morfológica confirmaram a existência de setores fibrosos e feixe de fibras de celulose
com diâmetro médio <9,7 e <7,2 μm, respectivamente. O espectro obtido pela técnica
de FTIR mostrou bandas características de grupos funcionais relacionados à celulose
(matriz principal), estruturas características das hemiceluloses (0,8%) e lignina (8,7%)
residuais, componentes de fibras lignocelulósicas. Portanto, fica evidenciado que
essas fibras são ricas em celulose com índice de cristalinidade de 66,93%. Os perfis
térmicos por DSC das fibras de celulose indicaram dois picos endotérmicos
observados a 57 e 360 °C, devido à eliminação da umidade e degradação da celulose
correspondente. No geral, as fibras de celulose extraídas da casca de arroz podem
ser potencialmente aplicadas em compósitos poliméricos funcionais dentro do
conceito da biorrefinaria.
The brazilian scenario suggests that rice husks are selected as an attractive potential to compose the “Cluster” of processes to synergetic production of foods, biofuels, bioproducts, pharmaceutical petrochemical intermediates, and biodegradable and renewable materials. This study aimed to investigate the isolation of cellulose fibers from the lignocellulosic matrix of the rice husk by coupling the following biorefining steps: diluted acid hydrolysis, alkaline treatment, and bleaching. The cellulose fibers extracted from the rice husk were examined according to their polymeric composition (~ 83%). However, it still has a lignin and ash content of ~ 8.7 and ~ 5.0%, respectively. The results of the morphological analysis confirmed the existence of fibrous sectors and bundles of cellulose fibers with an average diameter <9.7 and <7.2 μm, respectively. FT-IR spectra showed the characteristic bands associated with functional groups present in cellulose (main matrix), hemicelluloses (0.8%), and residual lignin (8.7%). Therefore, it is evident that these fibers are rich in cellulose with a crystallinity index of 66.93%. DSC curve of cellulose fibers indicated two endothermic peaks observed at 57 and 360 ° C, attributed to the removal of moisture and degradation of the corresponding cellulose. In general, cellulose fibers extracted from rice husk can potentially be applied in functional polymeric composites within the biorefinery concept.
The brazilian scenario suggests that rice husks are selected as an attractive potential to compose the “Cluster” of processes to synergetic production of foods, biofuels, bioproducts, pharmaceutical petrochemical intermediates, and biodegradable and renewable materials. This study aimed to investigate the isolation of cellulose fibers from the lignocellulosic matrix of the rice husk by coupling the following biorefining steps: diluted acid hydrolysis, alkaline treatment, and bleaching. The cellulose fibers extracted from the rice husk were examined according to their polymeric composition (~ 83%). However, it still has a lignin and ash content of ~ 8.7 and ~ 5.0%, respectively. The results of the morphological analysis confirmed the existence of fibrous sectors and bundles of cellulose fibers with an average diameter <9.7 and <7.2 μm, respectively. FT-IR spectra showed the characteristic bands associated with functional groups present in cellulose (main matrix), hemicelluloses (0.8%), and residual lignin (8.7%). Therefore, it is evident that these fibers are rich in cellulose with a crystallinity index of 66.93%. DSC curve of cellulose fibers indicated two endothermic peaks observed at 57 and 360 ° C, attributed to the removal of moisture and degradation of the corresponding cellulose. In general, cellulose fibers extracted from rice husk can potentially be applied in functional polymeric composites within the biorefinery concept.