Banca de QUALIFICAÇÃO: ANTONY JEOVA TEIXEIRA DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : ANTONY JEOVA TEIXEIRA DA SILVA
DATA : 21/02/2025
HORA: 08:30
LOCAL: https://meet.google.com/paw-rxxt-grc
TÍTULO:

DEVELOPMENT OF BETA ZEOLITES INCORPORATED WITH ZIRCONIUM FOR THE RECOVERY OF GLYCEROL

PALAVRAS-CHAVES:

Glycerol dehydration; acetol; Lewis acidity; beta zeolite; zirconium.

PÁGINAS: 91
GRANDE ÁREA: Outra
ÁREA: Ciências Ambientais
RESUMO:

In Brazil, biodiesel production has been growing in recent years, with glycerol being the main byproduct. Studies have been carried out to add value to glycerol and enable large-scale biodiesel production. The catalytic dehydration reaction of glycerol has been highlighted for promoting higher added value products. The use of zeolites to obtain higher added value products from glycerol is a promising strategy due to their properties such as high specific area, acidity, and shape selectivity. Thus, the objective of this work was to develop beta zeolites free of aluminum and with the presence of zirconium to increase the Lewis acidity and evaluate their catalytic activity in the dehydration reaction of glycerol aiming at selectivity for acetol. The hydrothermal synthesis of Zr-beta was carried out for 18 days in a hydrofluoric medium at the Si/Zr ratio = 200. The adapted methodology was performed using the Si/Zr ratios of 200 and 25, with different crystallization days: 5, 10 and 18 days. The obtained materials were characterized by XRD, TG and SEM-EDS. The dehydration reaction was carried out in a fixed bed, for 4 h and 10 h for the samples with better catalytic performance. And the aliquots were analyzed by chromatography. The X-ray diffractograms proved that the beta zeolite with incorporated Zr was obtained, both in the conventional and adapted synthesis, except for the synthesis with 18 days and Si/Zr = 25. The thermogravimetric analysis evidenced the thermal stability of the materials. The micrographs of the zeolites showed large crystals in the micrometer range and particles with truncated tetragonal bipyramidal shape, as well as possibly silica particles for the syntheses at Si/Zr = 25 ratios. The EDS mapping showed that the insertion of zirconium was efficient due to its good distribution. The catalysts showed high glycerol conversion as well as selectivity for acetaldehyde, acrolein and acetol. The beta zeolite at the ratio of 200 was stable for the tests with 10 h and its selectivity alternated between acetaldehyde and acetol throughout the synthesis time, showing itself to be a promising material for obtaining products of greater economic interest.

MEMBROS DA BANCA:
Externa à Instituição - MARIELE IARA SOARES DE MELLO - UFRN
Presidente - 7961 - ANNE GABRIELLA DIAS SANTOS CALDEIRA
Interno - 13136 - LEANDRO BEZERRA DE LIMA