Banca de DEFESA: VANESSA CASTRO DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : VANESSA CASTRO DE SOUZA
DATA : 24/07/2018
HORA: 14:00
LOCAL: Auditório do NUPPRAR
TÍTULO:

STUDY OF THE PROPERTIES OF NATURAL ZEOLITES MODIFIED BY ACID AND / OR BASIC TREATMENTS

PALAVRAS-CHAVES:

Natural Zeolites, Clinoptilolite, Modification, Experimental design, Gas storage.

PÁGINAS: 100
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

The zeolites are crystalline materials constituted by the union of tetrahedra (SiO4 and AlO4) that generate channels and cavities of molecular dimensions, with pore openings of up to 2nm. The natural zeolite Clinoptilolite (Si / Al ≥ 4), belonging to the Heulandite group, presents selectivity for small ray ions due to the size of its cavities. These natural materials are not obtained in their pure form, making treatments necessary for later application. Among the possible treatments to improve the properties, there is the crystal-particle modification that can be obtained by demetallization methods with hydrothermal, acidic, basic or steam treatment. Thus, it becomes feasible the use of natural zeolites, which present low cost, after modifications, so as to obtain improvements of properties and consequently are promising for treatment of effluents, catalytic cracking and gas storage. In this work structural modifications were carried out in natural zeolites Clinoptilolite, with acid and basic treatments, to improve textural properties using experimental statistical planning to control process variables. The acid treatment was the most effective for improving the textural properties (SBET increased from 27 to 165 m2/g), although the basic treatment, despite not having greatly increased the textural properties of the material, considerably increases the Brönsted acidity of the sample for preserving the aluminum. The zeolites clinoptilolites obtained from different deposits (ZNcelta, ZNchile and ZMcelta) were treated with acid (ZNceltaac, ZNchileac and ZMceltaac) that showed improvements in their textural properties. These samples were used in CO2 adsorption (308K) and presented efficient with an increase in the capture of 1.33mmol/g (ZNchile) to 1.9mmol / g (ZNchileac) and for storage of H2 (77K) showed with a considerable increase in storage capacity from 0.17 mmol/g (ZMcelta) to 2.52 mmol/g (ZMceltaac).

MEMBROS DA BANCA:
Externo ao Programa - 2140818 - AMANDA DUARTE GONDIM
Externo à Instituição - JHONNY VILLARROEL ROCHA - NOVA
Externo à Instituição - MANUEL KARIM SAPAG - UNSL
Interno - 1755267 - MARIA CAROLINA BURGOS COSTA DO NASCIMENTO
Externo à Instituição - MARIELE IARA SOARES DE MELLO - UFRN
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER