Banca de DEFESA: EVELLYN PATRICIA SANTOS DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : EVELLYN PATRICIA SANTOS DA SILVA
DATE: 30/05/2025
TIME: 09:00
LOCAL: Conferência Web - RNP
TITLE:

Catalysis in biorefinery routes: study of the reaction of levulinic acid with

glycerol in the presence of Sn(IV)-based catalysts

KEY WORDS:

biomass; esters; levulinic acid; tin(IV); glycerol; kinetics

PAGES: 110
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

This study investigated, for the first time, the use of a series of complexes based on Sn(IV) as
catalysts in the esterification of levulinic acid (LA) with glycerol (GLY): dibutyltin dichloride
(DBDC), dimethyltin dichloride (DMDC), butyltin trichloride (BTC), methyltin trichloride
(MTC), butylstanic acid (BTA), di-n-butyltin oxide (DBTO) and dibutyltin dilaurate
(DBTDL). The influences of various reaction conditions, including catalyst nature and
loading, reaction time, proportion of reactants, and temperature, were investigated. The most
active Sn(IV) complex (BTC; kap = 52,8 × 10−3 min−1) led to a GLY conversion of ∼ 74 %
in the first 15 min and ∼ 97 % in 360 min, with a total formation of 26.5 % GML, 56.0 %
GDL and 14.0 % GTL (360 min, 100 °C; molar ratio LA:GLI:CAT of 4:1:0.01). From the 

apparent rate constants (kap) determined at various temperatures, it was possible to estimate
the activation energy (AE) for the GLY conversion, which was 12.5 kJ mol−1 in the presence
of BTC and 24 kJ mol−1 for the reaction performed without a catalyst, representing a
decrease of approximately 50 % in the AE. This promising result associated with the
comparison with reactions performed and using conventional Bronsted acid catalysts
(hydrochloric acid (HCl) and p-toluenesulfonic acid (p-TsOH)) shows the potential of
systems based on Sn(IV), without the drawbacks associated with the use of the
aforementioned acids, such as reactor corrosion, among others.

COMMITTEE MEMBERS:
Externo(a) à Instituição - ANTONIO OSIMAR SOUSA DA SILVA
Interno(a) - 1869296 - CINTYA D'ANGELES DO ESPIRITO SANTO BARBOSA
Interno(a) - 1904678 - JANAINA HEBERLE BORTOLUZZI
Externo(a) à Instituição - SIBELE BERENICE CASTELLA PERGHER - UFRN
Presidente - 1515173 - SIMONI MARGARETI PLENTZ MENEGHETTI
Interno(a) - 1697766 - WANDER GUSTAVO BOTERO