Aproveitamento sustent?vel do baga?o de cana de a??car para obten??o do acetato de celulose

Autor: Silva, Valdic Luiz da
Jazyk: portugalština
Rok vydání: 2014
Předmět:
Zdroj: Repositório Institucional da UFRNUniversidade Federal do Rio Grande do NorteUFRN.
Druh dokumentu: masterThesis
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
O aproveitamento sustent?vel de res?duos decorrente da agroind?stria ? atualmente foco de pesquisas, com destaque para o baga?o de cana de a??car (BCA), por ser o res?duo lignocelul?sico produzido em maior volume na agroind?stria brasileira, onde a biomassa residual tem sido aplicada na produ??o de energia el?trica e bioprodutos. Neste trabalho, foi produzida celulose com elevada pureza, a partir do (BCA), por polpa??o soda/antraquinona e, posterior convers?o em acetato de celulose. A celulose comercial Avicel foi utilizada para compara??o. A obten??o do acetato de celulose ocorreu por rea??o de acetila??o homog?nea, modificando-se as vari?veis, tempo reacional, em horas, (8, 12, 16, 20 e 24) e temperatura, em ?C, (25 e 50). Os espectros de FTIR indicaram bandas caracter?sticas id?nticas para os materiais celul?sicos, o que demonstra a efici?ncia da separa??o por polpa??o. A caracteriza??o da celulose e do acetato obtidos ocorreu por espectroscopia de infravermelho (FTIR), difra??o de raios X (DRX), an?lises termogravim?tricas (TG/DTG/DSC), microscopia eletr?nica de varredura (MEV) e determina??o do grau de substitui??o (GS) para o acetato de celulose, para confirma??o da acetila??o. Os tempos reacionais ?timos para a obten??o de diacetatos e triacetatos, em ambas as temperaturas foram 20 h e 24 h. O acetato de celulose, produzido do BCA, apresentou GS entre 2,57 e 2,7 na temperatura de 25?C e, a 50 ?C, os GS obtidos foram 2,66 e 2,84, indicando real convers?o da celulose do BCA em di e triacetatos. De modo comparativo, a celulose comercial Avicel apresentou GS de 2,78 e 2,76 a 25 ?C e 2,77 e 2,75 a 50 ?C. Os dados foram obtidos no tempo de 20 h e 24 h, respectivamente. O melhor resultado ocorreu para a s?ntese do acetato de celulose obtida do BCA, com GS de 2,84 a 50?C e 24 h, sendo classificado como triacetato de celulose, que apresentou resultado superior ao acetato produzido com a celulose comercial Avicel, demonstrando a potencialidade de convers?o da celulose obtida a partir de um res?duo lignocelul?sicos (BCA), de baixo custo, com perspectivas de utiliza??o comercial do acetato de celulose
The sustainable use of waste resulting from the agribusiness is currently the focus of research, especially the sugar cane bagasse (BCA), being the lignocellulosic waste produced in greater volume in the Brazilian agribusiness, where the residual biomass has been applied in production energy and bioproducts. In this paper, pulp was produced in high purity from the (BCA) by pulping soda / anthraquinone and subsequent conversion to cellulose acetate. Commercial cellulose Avicel was used for comparison. The obtained cellulose acetate was homogeneous acetylation reaction by modifying the variables, the reaction time in hours (8, 12, 16, 20 and 24) and temperature in ? C (25 and 50). FTIR spectra showed characteristic bands identical to cellulosic materials, demonstrating the efficiency of separation by pulping. The characterization of cellulose acetate was obtained and by infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG / DTG / DSC), scanning electron microscopy (SEM) and determining the degree of substitution (DS ) for the cellulose acetate to confirm the acetylation. The optimal reaction time for obtaining diacetates and triacetates, at both temperatures were 20 and 24 h. Cellulose acetate produced BCA presented GS between 2.57 and 2.7 at 25 ? C and 50 ? C GS obtained were 2.66 and 2.84, indicating the actual conversion of cellulose BCA of di- and triacetates. Comparative mode, commercial cellulose Avicel GS showed 2.78 and 2.76 at 25 ? C and 2.77 to 2.75 at 50 ? C. Data were collected in time of 20 h and 24 h, respectively. The best result was for the synthesis of cellulose acetate obtained from the BCA GS 2.84 to 50 ? C and 24 hours, being classified as cellulose triacetate, which showed superior result to that produced with the commercial ethyl cellulose Avicel, demonstrating converting potential of cellulose derived from a lignocellulosic residue (BCA), low cost, prospects of commercial use of cellulose acetate
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