Unveiling the deactivation by coke of NiAl2O4 spinel derived catalysts in the bio-oil steam reforming: Role of individual oxygenates

The catalyst stability, mainly affected by coke deposition, remains being a challenge for the development of sustainable process hydrogen production steam reforming (SR) bio-oil. In this work, influence oxygenates composition in bio-oil on deactivation NiAl2O4 spinel derived has been approached studying SR wide range model with different functionalities, including acetic acid, acetone, ethanol, acetaldehyde, acetol, catechol, guaiacol and levoglucosan. A fluidized bed reactor was used following conditions: 600 700 °C; steam/carbon ratio, 3 (6 levoglucosan); space–time, 0.034 gcatalyst h/gbio-oil (low enough to favor rapid deactivation), and; time stream, 5 h. spent catalysts were analyzed several techniques, Temperature Programed Oxidation (TPO), X-ray Diffraction (XRD), N2 adsorption–desorption, Scanning Transmission Electron Microscopy (SEM, TEM) Raman Spectroscopy. main factors affecting stability are morphology, structure location coke, rather than its content, that depend nature oxygenate feed. deposition pyrolytic amorphous blocks Ni sites inhibiting formation filamentous carbon causes SR. Conversely, large amount nanotubes (CNTs) giving rise deposited aliphatic only slight deactivation. increase temperature significantly reduces but low impact