Banca de QUALIFICAÇÃO: MARIA ELIZABETH GEMAQUE COSTA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: MARIA ELIZABETH GEMAQUE COSTA
DATA: 21/09/2020
HORA: 09:30
LOCAL: via Google Meet
TÍTULO:

Textural, morphological, and mineralogical characterization of bio-adsorbents produced by hydrothermal processing of corn Stover with hot compressed H2O

PALAVRAS-CHAVES:

Corn Stover, Hydrothermal Processing, Solid Phase Characterization, Adsorption, Acetic Acid

PÁGINAS: 125
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
RESUMO:

This work aims to investigate the influence of temperature on textural, morphological, and mineralogical characterization of bio-adsorbents produced by hydrothermal processing of corn Stover with hot compressed H2O. The experiments were carried out at 175, 200, 225, and 250 ºC, reaction time of 240 minutes, heating rate of 2.0 ºC/min, and biomass-to-water ratio of 1:10, using a pilot scale stirred tank reactor of 5 gallon. The process performance analyzed in terms of yields of reaction products as a function of temperature. The results showed solid yields ranging from 62.92 to 35.82% (wt.), gas yields ranging between 1.49 and 9.59% (wt.), and reaction liquid products yields ranging from 35.43 to 54.59% (wt.). The solid phase yield decreases with increasing temperature, showing an inflection region between 200 and 225 °C, whereas a drastic change takes place, while that of liquid phase increases, showing also a drastic change between 200 and 225 °C. The yield of gaseous phase increases exponentially with temperature up to approximately 10% (wt.) within the investigated temperature range. The elemental analysis of solid products shows that carbon content increases, while that of oxygen and hydrogen decreases with increasing temperature. The textural, morphological, and mineralogical characterization of solid phase products analyzed by thermo-gravimetric analysis, scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction and BET. The solid phase product (bio-adsorbent) obtained by hydrothermal processing of corn Stover at 225 and 250 °C, reaction time of 240 minutes, and biomass-to-water ratio of 1:10, were activated chemically with 2.0 M NaOH and 2.0 M HCl solutions in order to investigate the adsorption of acetic acid solutions (1.0, 2.0, 3.0, and 4.0 mg/mL). The adsorption kinetics investigated at 30, 60, 120, 240, 480, and 960 seconds. The adsorption isotherms show that chemically activated hydrochars were able to recover acetic acid from aqueous solutions.

 

MEMBROS DA BANCA:
Externo ao Programa - 1546637 - ALESSANDRA SANTOS LOPES
Externo à Instituição - DOUGLAS ALBERTO ROCHA DE CASTRO
Externo ao Programa - 3445215 - HELIO DA SILVA ALMEIDA
Externo à Instituição - MARCELO COSTA SANTOS
Presidente - 1152662 - NELIO TEIXEIRA MACHADO
Interno - 1549677 - RAUL NUNES DE CARVALHO JUNIOR
Externo à Instituição - SERGIO DUVOISIN JUNIOR