Banca de QUALIFICAÇÃO: CAROLINA DA SILVA COSTA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : CAROLINA DA SILVA COSTA
DATE: 21/01/2025
TIME: 09:30
LOCAL: Virtual
TITLE:

Solvent-Free Hydrogenation of Succinic Acid and γ-Butyrolactone: A Sustainable Approach for Obtaining High-Value-Added Products

KEY WORDS:

Hydrogenation, Succinic Acid, γ-Butyrolactone, Solvent-Free, Green Processes.

PAGES: 93
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Operações Industriais e Equipamentos para Engenharia Química
SPECIALTY: Operações de Separação e Mistura
SUMMARY:

γ-butyrolactone (GBL) and succinic acid (SUC) are building-blocks molecules widely utilized in the synthesis of high-value-added compounds. Accordingly, this study aimed to evaluate the hydrogenation of these compounds under sustainable conditions, employing solvent-free systems and supercritical carbon dioxide (scCO₂), using bimetallic PdRe/SiO₂ catalysts. The solvent-free approach introduced an innovative aspect to the study, particularly for SUC, given its solid-state nature at room temperature. The reactions were analyzed using an experimental design, considering temperature and pressure as independent variables for GBL, while for SUC, the catalyst mass was also evaluated in addition to these factors. The influence of scCO₂ as a reaction medium was investigated for both systems. Furthermore, for SUC hydrogenation, the effect of rhenium content on reaction selectivity was assessed. The results revealed that the reaction medium significantly influenced the selectivity of GBL hydrogenation, acting as a modulating factor. Under solvent-free conditions, a selectivity of 93% for tetrahydrofuran (THF) was achieved. Conversely, with the addition of scCO₂, selectivity shifted entirely to 1,4-butanediol (BDO), reaching 100%. For SUC, the most severe conditions of temperature, pressure, and catalyst mass resulted in 75.3% selectivity for THF, while lower temperatures favored GBL formation, with selectivity reaching 89.9%. On the other hand, scCO₂ did not significantly reduce the formation of byproducts during SUC hydrogenation. However, increasing the rhenium content in the catalyst enhanced selectivity for THF to 80%, possibly due to an increase in acidic sites on the catalyst. These findings highlight the effectiveness of solvent-free approaches and the versatility of scCO₂ as a selectivity modulator, further emphasizing the potential of these systems for green and sustainable processes, achieving unprecedented selectivities for THF and BDO.

COMMITTEE MEMBERS:
Presidente - 1543286 - CAMILA GAMBINI PEREIRA COURTIAL
Interna - 1979301 - RENATA MARTINS BRAGA
Externa ao Programa - 1415657 - ANDREA OLIVEIRA NUNES - UFRNExterno à Instituição - PAULO FILHO MARQUES DE OLIVEIRA - USP
Externa à Instituição - FABÍOLA CORREIA DE CARVALHO
Externo à Instituição - PEDRO MIGUEL VIDINHA GOMES - USP