Catalytic steam reforming of biomass fast pyrolysis volatiles over Ni-Co bimetallic catalysts

[EN] The influence of the metal selected as catalytic active phase in the two-step biomass pyrolysis-catalytic reforming strategy has been analyzed. The pyrolysis step was carried out in a conical spouted bed reactor at 500 ºC, whereas steam reforming was performed in a fluidized bed reactor at 600...

Descripción completa

Detalles Bibliográficos
Autores: Santamaría Moreno, Laura, López Zabalbeitia, Gartzen, Arregi Joaristi, Aitor, Artetxe Uria, Maite, Amutio Izaguirre, Maider, Bilbao Elorriaga, Javier, Olazar Aurrecoechea, Martin
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/49922
Acceso en línea:http://hdl.handle.net/10810/49922
Access Level:acceso abierto
Palabra clave:hydrogen
pyrolysis
reforming
biomass
bimetallic catalysts
cobalt
Descripción
Sumario:[EN] The influence of the metal selected as catalytic active phase in the two-step biomass pyrolysis-catalytic reforming strategy has been analyzed. The pyrolysis step was carried out in a conical spouted bed reactor at 500 ºC, whereas steam reforming was performed in a fluidized bed reactor at 600 ºC. Ni/Al2O3, Co/Al2O3 and two bimetallic Ni-Co/Al2O3 catalysts with different metal loadings were synthesized by wet impregnation method, and fresh and deactivated catalysts were characterized by N2 adsorption/desorption, X-ray Fluorescence (XRF), Temperature Programmed Reduction (TPR), X-Ray powder Diffraction (XRD), Temperature Programmed Oxidation (TPO), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Although Ni/Al2O3 and both bimetallic catalysts had similar initial activity in terms of (oxygenate conversion, (higher than 98%), the poorer metal dispersion observed in both bimetallic catalysts led to a fast decrease in conversion due to the promotion of coke formation on large particles. This occurred even though Ni-Co alloy formation has a positive influence by hindering the oxidation of Co0 species. The main cause for the deactivation of these catalysts is the formation of a coke with amorphous structure. The poor initial performance of Co/Al2O3 catalyst is related to changes in the Co0 oxidation state induced by the presence of steam, which led to a fast deactivation of this catalyst.