Banca de DEFESA: BEATRIZ PINHEIRO DIAS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : BEATRIZ PINHEIRO DIAS
DATE: 17/07/2026
TIME: 14:00
LOCAL: video conferencia
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: 130
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
SPECIALTY: Cerâmicos
SUMMARY:

The need to protect and restore the environment has become a global concern faced by humanity. The reduction of greenhouse gas (GHG) emissions, particularly carbon dioxide (CO₂), has become a major priority for companies, industries, and governments as part of active efforts to mitigate environmental pollution. In this context, the development of materials capable of capturing CO₂ has attracted increasing attention, leading to a growing interest in adsorbent materials over recent years. Among these materials, zeolites have emerged as promising candidates to address this challenge.
In parallel with the development of zeolitic materials, different synthesis routes have been investigated to improve their performance, particularly through the use of natural raw materials and environmentally sustainable approaches. In this study, zeolitic materials were synthesized using four different methods, in which the mechanochemical route and kaolin as the source of silicon and aluminum were the main distinguishing features.
In Method 1, kaolin was first activated by milling in a planetary ball mill and subsequently employed in a conventional hydrothermal synthesis route for LTA zeolite. In Method 2, raw kaolin and the remaining reagents were simultaneously subjected to planetary ball milling, followed by hydrothermal treatment, characterizing a hybrid mechanochemical–hydrothermal synthesis route. In Method 3, the synthesis was carried out exclusively through mechanochemical activation in a planetary ball mill, followed only by a aging step under controlled temperature, without hydrothermal treatment. Finally, in Method 4, the reaction mixture was processed in a rotating autoclave under controlled temperature, promoting simultaneous agitation and crystallization during the synthesis process.
All synthesized materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and N₂ adsorption analyses. Their CO₂ capture performance was evaluated through fixed-bed adsorption tests, enabling the determination of CO₂ adsorption capacity. Selected samples were also characterized using particle size analysis (PSA).
The results demonstrated that the milling process promoted significant amorphization of kaolin, reaching values above 80% under more intensive milling conditions, such as longer milling times and higher rotational speeds. Zeolitic materials were successfully synthesized; however, the formation of a mixed phase composed of LTA zeolite and sodalite was observed, with the LTA phase predominating in most samples. The application of these materials for CO₂ capture was evaluated, and the results obtained thus far indicate promising potential for this purpose.

 

COMMITTEE MEMBERS:
Presidente - 1308577 - SIBELE BERENICE CASTELLA PERGHER
Interno - 1298936 - ANTONIO EDUARDO MARTINELLI
Externo à Instituição - ADONAY RODRIGUES LOIOLA - UFC
Externa à Instituição - LINDIANE BIESEKI - UFRN
Externo à Instituição - LUIZ CARLOS BERTOLINO - CETEM