New understandings on the catalytic dehydration of bioethanol to ethylene at low temperature
- Autores: Lamiae Ouayloul
- Directores de la Tesis: Iker Aguirrezabal Telleria (dir. tes.), Mohamed El Doukkali (dir. tes.)
- Lectura: En la Universidad del País Vasco - Euskal Herriko Unibertsitatea ( España ) en 2024
- Idioma: inglés
- Tribunal Calificador de la Tesis: Mohamed Ouzzine (presid.), Nour-eddine El Mansouri (secret.), Mohamed El Doukkali (voc.), Esther Acha Peña (voc.), Fatimi Ahmed (voc.)
- Programa de doctorado: Programa de Doctorado en Ingeniería de Materiales y de Procesos Sostenibles / Engineering of Materials and Sustainable Processes por la Universidad del País Vasco/Euskal Herriko Unibertsitatea
- Materias:
- Enlaces
- Tesis en acceso abierto en: ADDI
- Resumen
This present PhD thesis takes advantage of the excess of bioethanol in the market, which rises mostly from fermentative processes and increasing electric car sales. The research efforts made on the "bioethanol-to-bioethylene" route focus in shifting the research towards lowering the reaction temperature instead of only increasing ethanol-to-ethylene yield, while offering novel insights in how dehydration events progress over typical acid zeolites (ZSM-5 and BEA). Different strategies (hierarchization, water treatment, heteroatoms doping, NH3 titration) have been explored for re-modulating the properties of Al-rich and Si-rich ZSM-5-based catalysts to reach substantial progress on ethanol dehydration at low-temperature (200-225 °C). Thus, an unprecedented ethylene selectivity (up 97 %) has been reached, depending on parameters such as temperature and spaces-velocity. Moreover, a treatment with H2O and/or CeOx species brings positive effects both in zeolite properties and in the course of ethanol-to-ethylene reaction. Coupling kinetic tests and theoretical calculations allowed to unveil a cooperative effect between Brønsted-and Lewis-acid sites that seem to play a key role in ethylene formation at low-temperature.
