Banca de QUALIFICAÇÃO: HELOISE OLIVEIRA MEDEIROS DE ARAÚJO MOURA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : HELOISE OLIVEIRA MEDEIROS DE ARAÚJO MOURA
DATA : 30/05/2019
HORA: 14:00
LOCAL: auditório do Química III
TÍTULO:

Assessing the efficiency of residual biomass pre-treatments in isolating high accessibility celluloses for the production of chemical platforms

PALAVRAS-CHAVES:

Cellulose; Residual biomass; Combined pretreatment; Ultrasound; Crystallinity

PÁGINAS: 80
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Orgânica
ESPECIALIDADE: Química dos Produtos Naturais
RESUMO:

Cellulose is an extremely abundant and promising material for the production of various platform substances for biorefinery from residual lignocellulose; however, the development of treatments for disrupting biomass and effectively extract cellulose is still under study. This work aimed to evaluate the effect of the acid/peroxide-alkaline (APA) combined pre-treatment assisted by ultrasound cavitation in obtaining cellulose with high purity and accessibility from sugarcane bagasse (Saccharum officinarum), corn cob (Zea mays), prickly pear pseudocaule (Opuntia ficus-indica L. Mill.) and the bagasse of a genetically modified sugarcane. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) associated to the PeakFit v4.12 software where used to characterize the obtained celluloses. The efficiency of the pretreatments was assessed by inferring crystallinity parameters of the samples. The use of ultrasound in the combined treatment proved to be effective in reducing the recalcitrance of the lignocellulosic structure. The celluloses were characterized by the analytical procedure NREL/TP-510-42618, thermogravimetric analysis (TG/DTG), scanning electron microscopy (SEM), FTIR and XRD. The results of high performance liquid chromatography (HPLC) confirmed the high purity of the cellulose extracted from sugarcane bagasse (85.67%), and the XRD patterns showed the mixture of cellulose polymorphs (types I, II and amorphous) present in the sample and its low crystallinity, thus enabling the isolation of highly reactive celluloses for the production of high added value chemicals.

MEMBROS DA BANCA:
Externa à Instituição - LEILA MARIA AGUILERA CAMPOS - UNIFACS
Presidente - 1805556 - LUCIENE DA SILVA SANTOS
Externa ao Programa - 433663 - MARTA COSTA
Interna - 1308577 - SIBELE BERENICE CASTELLA PERGHER