TY - JOUR
T1 - Regeneration of NiAl2O4 spinel type catalysts used in the reforming of raw bio-oil
AU - Remiro, A.
AU - Arandia, A.
AU - Oar-Arteta, L.
AU - Bilbao, J.
AU - Gayubo, A.G.
PY - 2018
Y1 - 2018
N2 - The regenerability of Ni catalysts in reforming reactions is a key factor for process viability. Accordingly, this study addresses the regeneration of two spinel NiAl
2O
4 type catalysts by reaction-regeneration cycles in the oxidative steam reforming (OSR) of raw bio-oil. The spinel type catalysts were prepared by different methods including a supported Ni/La
2O
3-αAl
2O
3 catalyst and a bulk NiAl
2O
4 catalyst. The experimental set-up consists of two units connected in series for i) the thermal treatment of bio-oil at 500 °C, in order to control the deposition of pyrolytic lignin, followed by; ii) the oxidative steam reforming (OSR) of the remaining oxygenates in a fluidized bed catalytic reactor. The conditions in the OSR reaction step were: 700 °C; oxygen/steam/carbon ratio (O/S/C), 0.34/6/1; space time, 0.75 g
catalysth/g
bio-oil (for supported catalyst) and 0.15 g
catalysth/g
bio-oil (for bulk catalyst). Three different strategies have been studied in the regeneration step by coke combustion, including the in situ regeneration inside the reactor at 650 °C and 850 °C, and the ex situ regeneration in an external oven at 850 °C, for 4 h in all the cases. The behavior of the fresh and regenerated catalysts has been explained according to their metallic properties, determined by different characterization techniques (temperature programmed reduction (TPR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electronic microscopy (TEM)). According to these results, the combustion ex situ of the catalyst at 850 °C is able to completely regenerate the bulk catalyst, since these regeneration conditions lead to the total recovery of the NiAl
2O
4 spinel phase together with negligible loss of Ni on the surface in the catalyst. These novel results are crucial for future industrial implementation of the process.
AB - The regenerability of Ni catalysts in reforming reactions is a key factor for process viability. Accordingly, this study addresses the regeneration of two spinel NiAl
2O
4 type catalysts by reaction-regeneration cycles in the oxidative steam reforming (OSR) of raw bio-oil. The spinel type catalysts were prepared by different methods including a supported Ni/La
2O
3-αAl
2O
3 catalyst and a bulk NiAl
2O
4 catalyst. The experimental set-up consists of two units connected in series for i) the thermal treatment of bio-oil at 500 °C, in order to control the deposition of pyrolytic lignin, followed by; ii) the oxidative steam reforming (OSR) of the remaining oxygenates in a fluidized bed catalytic reactor. The conditions in the OSR reaction step were: 700 °C; oxygen/steam/carbon ratio (O/S/C), 0.34/6/1; space time, 0.75 g
catalysth/g
bio-oil (for supported catalyst) and 0.15 g
catalysth/g
bio-oil (for bulk catalyst). Three different strategies have been studied in the regeneration step by coke combustion, including the in situ regeneration inside the reactor at 650 °C and 850 °C, and the ex situ regeneration in an external oven at 850 °C, for 4 h in all the cases. The behavior of the fresh and regenerated catalysts has been explained according to their metallic properties, determined by different characterization techniques (temperature programmed reduction (TPR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electronic microscopy (TEM)). According to these results, the combustion ex situ of the catalyst at 850 °C is able to completely regenerate the bulk catalyst, since these regeneration conditions lead to the total recovery of the NiAl
2O
4 spinel phase together with negligible loss of Ni on the surface in the catalyst. These novel results are crucial for future industrial implementation of the process.
KW - Bio-oil
KW - Hydrogen production
KW - Ni-Al spinel
KW - Reforming
KW - Regeneration
UR - http://www.scopus.com/inward/record.url?scp=85048543080&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2018.06.005
DO - 10.1016/j.apcatb.2018.06.005
M3 - Article
SN - 0926-3373
VL - 237
SP - 353
EP - 365
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
ER -