Banca de DEFESA: THIAGO WINICIO ROCHA LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : THIAGO WINICIO ROCHA LIMA
DATE: 17/06/2025
TIME: 08:00
LOCAL: PGTEC
TITLE:

MODIFIED PHASE INVERSION APPLIED TO THE PRODUCTION OF Ce2(WO4)3 MEMBRANES IN 3D PRINTED MOLDS

 

KEY WORDS:

Helical tubular dead-end membrane, 3D printed mold, cerium tungstate.

PAGES: 113
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Operações Industriais e Equipamentos para Engenharia Química
SPECIALTY: Operações de Separação e Mistura
SUMMARY:

Climate change driven by greenhouse gas (GHG) emissions is already impacting regions worldwide, manifesting through extreme weather events. Methane (CH4) stands out due to its high short-term warming potential, necessitating research and investment in technologies for direct removal at emission sources. Studies have explored catalytic ceramic membrane reactors (e.g., perovskites, tungstates) to convert methane into syngas (CO+H₂), a feedstock for industrial and energy applications. Despite progress, further investigations into innovative membrane geometries are critical, as geometry plays a crucial role in gas separation efficiency. This study developed and characterized dense ceramic membranes of cerium tungstate (Ce₂(WO₄)₃) in disk and helical tubular configurations. Ce₂(WO₄)₃ was synthesized via the EDTA-Citrate sol-gel complexation method. A tungsten precursor (WO₃) was obtained through acid leaching of scheelite concentrate (a tungsten ore). Phase inversion casting was employed, testing polysulfone (PSU), polyethersulfone (PES), glass fiber-reinforced PES (PES+f), and polyphenylsulfone (PPSU) polymers in a custom 3D-printed mold. WO₃ and Ce₂(WO₄)₃ powders were characterized by X-ray fluorescence (XRF) for elemental composition, X-ray diffraction (XRD) confirming phases via ICSD 050727 and 401920 reference patterns, and scanning electron microscopy (SEM) revealing material morphologies. PES powder exhibited optimal solubility in NMP at 25°C (20 min). Green membranes (disk and helical tube) were formed using a slurry with 72% ceramic loading. Thermogravimetric and dilatometric analyses determined polymer burn-off at 600°C and sintering at 1,000°C for 7 h. Sintered membranes displayed desired asymmetry, with dense bases, surface pores and a good uniform element distribution. Results underscore the material’s potential for asymmetric applications, contingent on optimizing tubular geometries for mechanical stability and testing oxygen permeability and methane conversion in membrane reactors.

COMMITTEE MEMBERS:
Presidente - 349801 - CARLSON PEREIRA DE SOUZA
Interna - 1271737 - CAMILA PACELLY BRANDÃO DE ARAÚJO
Interno - 1149554 - OSVALDO CHIAVONE FILHO
Externa ao Programa - 1218001 - LIANA FRANCO PADILHA - UFRNExterna à Instituição - MAITÊ MEDEIROS DE SANTANA E SILVA - UFRN