Unveiling the deactivation by coke of NiAl2O4 spinel derived catalysts in the bio-oil steam reforming: Role of individual oxygenates
Year: 2022
Type: article
Abstract: The catalyst stability, mainly affected by coke deposition, remains being a challenge for the development of a sustainable process for hydrogen production by steam reforming (SR) of bio-oil. In this work, the influence of oxygenates composition in bio-oil on the deactivation by coke of a NiAl2O4 spinel derived catalyst has been approached by studying the SR of a wide range of model oxygenates with different functionalities, including acetic acid, acetone, ethanol, acetaldehyde, acetol, catechol, guaiacol and levoglucosan. A fluidized bed reactor was used in the following conditions: 600 and 700 °C; steam/carbon ratio, 3 (6 for levoglucosan); space–time, 0.034 gcatalyst h/gbio-oil (low enough to favor the rapid catalyst deactivation), and; time on stream, 5 h. The spent catalysts were analyzed with several techniques, including Temperature Programed Oxidation (TPO), X-ray Diffraction (XRD), N2 adsorption–desorption, Scanning and Transmission Electron Microscopy (SEM, TEM) and Raman Spectroscopy. The main factors affecting the catalyst stability are the morphology, structure and location of coke, rather than its content, that depend on the nature of the oxygenate feed. The deposition of pyrolytic and amorphous coke that blocks the Ni sites inhibiting the formation of filamentous carbon causes a rapid deactivation in the guaiacol SR. Conversely, the large amount of carbon nanotubes (CNTs) giving rise to a filamentous coke deposited in the SR of aliphatic oxygenates only causes a slight deactivation. The increase in the temperature significantly reduces coke deposition, but has low impact on deactivation.
Source: Fuel
Institution: University of the Basque Country
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,770
Funders: U.S. Department of Education, European Commission, Eusko Jaurlaritza, Euskal Herriko Unibertsitatea, Ministerio de Ciencia e Innovación, Ministerio de Asuntos Económicos y Transformación Digital, Gobierno de España, Horizon 2020 Framework Programme, Universitat Politècnica de València, European Regional Development Fund, Agencia Estatal de Investigación
Awards: G121809054, G1542017954, G1622782223, G1650125035, G1723464023, G1855990336, G2262748287, G2309174360, Biomass gasification with negative carbon emission through innovative CO2 capture and utilisation and integration with energy storage, G2628364946, G2660406951, G3279731299, G3345895242, G3424664161, G3480869486, G3518538256, G3554954424, G3611378902, G3681454997, G3718128086, G4033406476, G4042783231, G425668148, G4442677895, G451917667, G4526231891, G4551342717, G4836688517, G4881896942, G4937468798, G5080475149, G5181308595, G526084217, G5421974903, G5523395981, G5943232429, G5967599077, G6298273575, G683931746, G7084143925, G7169023097, G7213747625, G7625670470, G7947147558, G8512683158, G8686138465, G897484643
OpenAlex ID: W4226280166