Banca de DEFESA: RAISA AMORIM SACRAMENTO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAISA AMORIM SACRAMENTO
DATE: 31/03/2023
TIME: 08:00
LOCAL: Defesa por Videoconferencia
TITLE:

MESOPOROUS SILICA MATERIALS TEMPLATED WITH SUCROSE FOR CO₂ ADSORPTION

KEY WORDS:

mesoporous silica materials; sucrose; CO₂ adsorption

PAGES: 86
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Petróleo e Petroquímica
SUMMARY:

The capture and storage of carbon dioxide (CO2) has been indicated as an effective strategy to reduce the emissions of this gas with the greatest impact on the greenhouse effect. Several studies have focused on the application of mesoporous silica materials in CO2 adsorption processes. And SBA-15 has stood out as a CO2 capture capture agent to its large pore volume and diameter and high thermal and hydrothermal performance. However, the synthesis of these materials still has a high cost due to the complexity in the processing to obtain tetraethylorthosilicate and the use of synthetic surfactants to model these materials. The objective of the present work was the synthesis of mesoporous silica materials, using sodium silicate (Na2SiO3) as a silica source and sucrose as a structure modeler, for the adsorption of CO2. The materials were synthesized with sucrose in different molar ratio (0, 0,3, 1, 2 e 3) in relation to silica (SiO2). The structures of mesoporous were prepared and characterized by thermogravimetric analysis (TG/DTG) and nitrogen adsorption at -196°C, confirming the formation of a mesoporous silica structure and showing that increasing sucrose composition during synthesis resulted in improved properties and textures of these materials. The samples prepared with higher sucrose composition obtained the best results obtained the best results for surface area, 322 and 343 m2 ∙g-1, and pore diameter, 7 and 9 nm, respectively. The results obtained in the adsorption tests found that the structures synthesized with sucrose correlated better with the Elovich Kinetic model, indicating that chemisorption is a rate-limiting step in the CO2 adsorption process of these materials. The adsorbents prepared with higher sucrose composition showed better adsorption capacities, 44.37 and 47.81 mg.g-1, respectively, reaching adsorption capacity superior to other mesoporous silica structures.

BANKING MEMBERS:
Presidente - 1545506 - ANTONIO OSIMAR SOUSA DA SILVA
Interno(a) - 1121112 - JOAO INACIO SOLETTI
Interno(a) - 2278469 - LEONARDO MENDONÇA TENÓRIO DE MAGALHÃES OLIVEIRA
Externo(a) à Instituição - JOHNNATAN DUARTE DE FREITAS - IFAL
Externo(a) à Instituição - PAULO HENRIQUE LEITE QUINTELA - UFS