TY - JOUR
T1 - On the dynamics and reversibility of the deactivation of a Rh/CeO2-ZrO2 catalyst in raw bio-oil steam reforming
AU - Remiro, A.
AU - Ochoa, A.
AU - Arandia, A.
AU - Castaño, P.
AU - Bilbao, J.
AU - Gayubo, A.G.
PY - 2019
Y1 - 2019
N2 - The deactivation mechanism of a commercial Rh/CeO2–ZrO2 catalyst in raw bio-oil steam reforming has been studied by relating the evolution with time on stream of the bio-oil conversion and products yields and the physicochemical properties of the deactivated catalyst studied by XRD, TPR, SEM, XPS, TPO and TEM. Moreover, the reversibility of the different deactivation causes has been assessed by comparing the behavior and properties of the catalyst fresh and regenerated (by coke combustion with air). The reactions were carried out in an experimental device with two units in series: a thermal treatment unit (at 500 °C, for separation of pyrolytic lignin) and a fluidized bed reactor (at 700 °C, for the reforming reaction). The results evidence that structural changes (support aging involving partial occlusion of Rh species) are irreversible and occur rapidly, being responsible for a first deactivation period, whereas encapsulating coke deposition (with oxygenates as precursors) is reversible and evolves more slowly, thus being the main cause of the second deactivation period. The deactivation selectively affects the reforming of oxygenates, from least to greatest reactivity. Rh sintering is not a significant deactivation cause at the studied temperature.
AB - The deactivation mechanism of a commercial Rh/CeO2–ZrO2 catalyst in raw bio-oil steam reforming has been studied by relating the evolution with time on stream of the bio-oil conversion and products yields and the physicochemical properties of the deactivated catalyst studied by XRD, TPR, SEM, XPS, TPO and TEM. Moreover, the reversibility of the different deactivation causes has been assessed by comparing the behavior and properties of the catalyst fresh and regenerated (by coke combustion with air). The reactions were carried out in an experimental device with two units in series: a thermal treatment unit (at 500 °C, for separation of pyrolytic lignin) and a fluidized bed reactor (at 700 °C, for the reforming reaction). The results evidence that structural changes (support aging involving partial occlusion of Rh species) are irreversible and occur rapidly, being responsible for a first deactivation period, whereas encapsulating coke deposition (with oxygenates as precursors) is reversible and evolves more slowly, thus being the main cause of the second deactivation period. The deactivation selectively affects the reforming of oxygenates, from least to greatest reactivity. Rh sintering is not a significant deactivation cause at the studied temperature.
KW - Bio-oil
KW - Deactivation
KW - Hydrogen
KW - Rh catalyst
KW - Steam reforming
UR - http://www.scopus.com/inward/record.url?scp=85059444452&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2018.12.073
DO - 10.1016/j.ijhydene.2018.12.073
M3 - Article
SN - 0360-3199
VL - 44
SP - 2620
EP - 2632
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
IS - 5
ER -
