Banca de DEFESA: RUTHINEIA JESSICA ALVES DO NASCIMENTO
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.DISCENTE : RUTHINEIA JESSICA ALVES DO NASCIMENTO
DATA : 29/06/2016
HORA: 14:00
LOCAL: AUDITÓRIO DO PPGEQ
TÍTULO:
Real time monitoring of enzymatic hydrolysis of coconut husk by Near-infrared spectroscopy (NIRS)
PALAVRAS-CHAVES:
monitoring, NIRS, enzymatic hydrolysis, second generation ethanol.
PÁGINAS: 135
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
RESUMO:
This study, in a first step, investigates the application of near infrared spectroscopy for rapid qualitative characterization of coconut husk fiber and evaluates the potential of this lignocellulosic material for the production of second-generation ethanol. In a second step, the near infrared spectroscopy associated with methods of data mathematical pretreatment and multivariate calibration methods have been investigated for their potential for real time monitoring of coconut husk fiber enzymatic hydrolysis process. The coconut husk was subjected to four types of physico-chemical pretreatments: Pre-treatment with dilute sulfuric acid (2% w/v), pre-treatment with dilute phosphoric acid (0.2% w/v), alkaline pre-treatment (NaOH 0.5% w/v) and hydrothermal pre-treatment. Morphological changes, chemical composition and crystallinity index variations caused by the physical-chemical pre-treatments, were evaluated. Also, the pretreatments influence in enzymatic hydrolysis yield and the theoretical ethanol yield were investigated. Changes in lignin, hemicellulose and crystalline cellulose were characterized by traditional methods such as SEM and XRD and using an alternative analytical method using NIR spectroscopy, and good results were obtained. Pretreatment with dilute phosphoric acid proved to be more efficient when the aim is the production of bioethanol, resulting in 39.16% of enzymatic hydrolysis yield and 83.68 L/t of theoretical ethanol yield. The monitoring calibration models were built and optimized with the cross-validation process and the models predictive ability were analyzed by the external validation. The mathematical pretreatments performed on spectral data were Standard normal variation (SNV), Multiplicative scatter correction (MSC) and Smoothing moving average (SMA) coupled with 1st and 2nd derivative of Savitzky-Golay. The best calibration models for quantification of ART, glucose, cellulose conversion and the theoretical ethanol yield were obtained for the mathematical pretreatment SMA + 2nd derivative having R2 and RMSEP values equal to, 0.98 and 0.1994 g.L-1, for ART; 0.99 and 0,0266 g.L-1 for glucose; 0.99 and 0.1839% for cellulose conversion; 0.99 and 0.2279 L/t of theoretical ethanol yield. The obtained calibration models were used for monitoring an enzymatic hydrolysis process of coconut husk with satisfactory results.
MEMBROS DA BANCA:
Externo ao Programa - 1584174 - DOMINGOS FABIANO DE SANTANA SOUZA
Interno - 1346198 - EVERALDO SILVINO DOS SANTOS
Presidente - 347401 - GORETE RIBEIRO DE MACEDO
Interno - 1547970 - JACKSON ARAUJO DE OLIVEIRA
Externo à Instituição - MARCELO PERENCIN DE ARRUDA RIBEIRO - UFSCAR
Externo à Instituição - SOLANGE MARIA DE VASCONCELOS - UFPB