Banca de QUALIFICAÇÃO: VANESSA CASTRO DE SOUZA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : VANESSA CASTRO DE SOUZA
DATA : 20/04/2017
HORA: 09:00
LOCAL: Auditório do CCET
TÍTULO:

MODIFICATIONS OF NATURAL ZEOLITES FOR REMEDIATION OF EFFLUENTS AND CATALYTIC REACTIONS

PALAVRAS-CHAVES:

Natural Zeolites, Acid / Basic Treatment and Experimental design

PÁGINAS: 60
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

The zeolites have in their composition crystalline structures consisting of (SiO4) and (AlO4) tetrahedra connected through the oxygen atoms at their apexes, which together generate channels and cavities of molecular dimensions, with pore openings of up to 2nm (micropores). There are several types of zeolites, which can be found in nature (natural) or can be synthesized (synthetic) and have wide applications, including catalysis and adsorption. The natural zeolite Clinoptilolite is of the Heulandite group, with Si / Al ratio greater than or equal to 4. This zeolite presents selectivity for small ray ions due to their cavities, but these natural materials do not come in their pure form, Necessary treatments for later application. Among the types of modifications, crystal-particle modification can be achieved by demetallation methods with hydrothermal, acidic, basic or steam treatment. Thus, it becomes feasible the use of natural zeolites that present low cost, with modifications, so that it can give rise to a material with improvements of properties and promising for treatment of effluents and catalytic cracking. However, the effectiveness of the treatment for material optimization depends on several parameters that can be adjusted. In this work structural modifications were carried out in natural zeolites Clinoptilolite, with acid and basic treatments, for opening of mesoporosity and thus obtaining of hierarchical material and later applications. For acid treatment with nitric acid was used varying parameters such as time, temperature and concentration. The acid treatment resulted in a considerable removal of aluminum since the Si / Al ratio of untreated natural zeolite was 4.71 and after treatment that value doubled for the sample E8ZNceltaac (Si / Al = 10.07) and E12ZNceltaac (Si / Al = 9.57), indicating the possible increase of porosity with pore opening, in addition the experimental design was not satisfactory for crystallinity evaluation.

MEMBROS DA BANCA:
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 1755267 - MARIA CAROLINA BURGOS COSTA DO NASCIMENTO
Externo ao Programa - 007.566.270-10 - LINDIANE BIESEKI - UFRN
Externo à Instituição - MANUEL KARIM SAPAG - UNSL