Banca de QUALIFICAÇÃO: BEATRIZ PINHEIRO DIAS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : BEATRIZ PINHEIRO DIAS
DATE: 24/03/2026
TIME: 14:00
LOCAL: online
TITLE:

Development of materials for CO2 storage through the mechanochemical transformation of kaolin into LTA zeolite.

KEY WORDS:

Zeolite, CO2 Adsorption, Greenhouse Gases, Green Synthesis, Kaolin.

PAGES: 120
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

The need to protect and restore the environment is a universal concern faced by humanity. The reduction of greenhouse gases (GHG), such as carbon dioxide (CO₂), has generated a great alert among companies, industries, and countries, as a way to actively combat environmental pollution. In this regard, the development of materials capable of capturing CO₂ has been gaining increasing prominence, so that adsorbent materials have expanded their space in recent years. Thus, zeolitic materials emerge as an opportunity to help with this problem.
Linked to the development of zeolites, different synthesis routes have been studied with the aim of achieving better performance, especially through the application of routes that use natural materials or that can be considered more environmentally sustainable. In this work, zeolitic materials were developed from a synthesis considered green, via mechanochemistry, using kaolin as a source of Si and Al.
Four synthesis methods were studied and, consequently, the results obtained were discussed. In method 1, kaolin previously ground by a milling process was applied in a conventional LTA zeolite synthesis route. In method 2, the kaolin was added in its natural state along with the other reagents directly to the ball mill, followed by a hydrothermal process, thus configuring a hybrid synthesis process. Method 3 consisted of a fully mechanochemical process, followed only by an aging step. In method 4, the material was subjected to a rotating autoclave under controlled temperature.

All materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) analyses, and N₂ and CO₂ adsorption tests in a fixed bed, with the aim of calculating the CO₂ adsorption capacity. Some samples were also subjected to particle size analysis by PSA.
The results indicate that the milling process promoted the amorphization of kaolin by more than 80% when more intense milling conditions were applied, such as longer times and higher speeds. Zeolites were obtained according to the results presented; however, the formation of a mixture of LTA zeolite and sodalite was observed, with the LTA phase being predominant in most samples. The application of these materials in CO₂ capture was evaluated and, so far, the results have shown promise for this purpose.

 

COMMITTEE MEMBERS:
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externa ao Programa - ***.566.270-** - LINDIANE BIESEKI - UFRN
Externo à Instituição - ADONAY RODRIGUES LOIOLA - UFC