Catalytic performance of bulk and Al2O3-supported molybdenum oxide for the production of biodiesel from oil with high free fatty acids content

Non-edible vegetable oils are characterized by high contents of free fatty acids (FFAs) that prevent from using the conventional basic catalysts for the production of biodiesel. In this work, solid acid catalysts are used for the simultaneous esterification and transesterification with methanol of t...

Descripción completa

Detalles Bibliográficos
Autores: Navajas, Alberto, Reyero, Inés, Jiménez Barrera, Elena Mª, Romero Sarria, Francisca, Llorca, Jordi, Gandía, Luis M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/98110
Acceso en línea:https://hdl.handle.net/11441/98110
https://doi.org/10.3390/catal10020158
Access Level:acceso abierto
Palabra clave:Acid catalysis
Biodiesel
Biofuel
Esterification
Fatty acid
Methanolysis
Molybdenum oxide
Transesterification
Vegetable oil
Descripción
Sumario:Non-edible vegetable oils are characterized by high contents of free fatty acids (FFAs) that prevent from using the conventional basic catalysts for the production of biodiesel. In this work, solid acid catalysts are used for the simultaneous esterification and transesterification with methanol of the FFAs and triglycerides contained in sunflower oil acidified with oleic acid. Molybdenum oxide (MoO3), which has been seldom considered as a catalyst for the production of biodiesel, was used in bulk and alumina-supported forms. Results showed that bulk MoO3 is very active for both transesterification and esterification reactions, but it suffered from severe molybdenum leaching in the reaction medium. When supported on Al2O3, the MoO3 performance improved in terms of active phase utilization and stability though molybdenum leaching remained significant. The improvement of catalytic performance was ascribed to the establishment of MoO3Al2O3 interactions that favored the anchorage of molybdenum to the support and the formation of new strong acidic centers, although this effect was offset by a decrease of specific surface area. It is concluded that the development of stable catalysts based on MoO3 offers an attractive route for the valorization of oils with high FFAs content.