TY - JOUR
T1 - Kinetic studies of hydrodeoxygenation of 2-methyltetrahydrofuran on a Ni2P/SiO2 catalyst at medium pressure
AU - Iino, Ayako
AU - Cho, Ara
AU - Takagaki, Atsushi
AU - Kikuchi, Ryuji
AU - Ted Oyama, S.
N1 - Funding Information:
This work was supported by Development of Next-generation Technology for Strategic Utilization of Biomass Energy of New Energy and Industrial Technology Development Organization (NEDO), Japan and by the US Department of Energy, Office of Basic Energy Sciences , through Grant DE- FG02-963414669 .
PY - 2014/3
Y1 - 2014/3
N2 - Bio-oil obtained by the pyrolysis of woody biomass contains many oxygenated organic compounds which degrade the product quality and make necessary upgrading for its use as a liquid fuel. Hydrodeoxygenation (HDO) is a catalytic hydrotreating process for the removal of the problematic oxygen functionalities and is promising for bio-oil upgrading. In this work, 2-methyltetrahydrofuran (2-MTHF) was chosen as a model oxygenated compound, and its HDO reaction mechanism was studied on a silica-supported nickel phosphide catalyst (Ni 2P/SiO2) at a medium pressure of 0.5 MPa. The temperature dependency of the catalyst activity was determined and it was found that at 350 C Ni2P/SiO2 showed 100% conversion and 85% selectivity to n-pentane, with higher oxygen removal activity and less CC bond cracking activity than commercial noble metal Ru/C and Pd/Al2O3 catalysts based on the same amount of active sites. A contact time study allowed the determination of a reaction sequence for 2-MTHF HDO on Ni 2P/SiO2 and it was found that CO bond cleavage of the furanic ring to generate either 2-pentanone or 1-pentanal was the rate-determining step. This was followed by hydrogen transfer steps to produce oxygen free compounds, n-pentane or n-butane. A partial pressure analysis of 2-MTHF and H2 was consistent with a rate equation derived using a Langmuir-Hinshelwood (L-H) mechanism. This suggested that adsorption of 2-MTHF and hydrogen occurred competitively and that these species reacted on the Ni2P/SiO2 surface. Although high partial pressure of H2 was favorable for hydrogenation, too much H2 competed with 2-MTHF adsorption, which caused lower conversion.
AB - Bio-oil obtained by the pyrolysis of woody biomass contains many oxygenated organic compounds which degrade the product quality and make necessary upgrading for its use as a liquid fuel. Hydrodeoxygenation (HDO) is a catalytic hydrotreating process for the removal of the problematic oxygen functionalities and is promising for bio-oil upgrading. In this work, 2-methyltetrahydrofuran (2-MTHF) was chosen as a model oxygenated compound, and its HDO reaction mechanism was studied on a silica-supported nickel phosphide catalyst (Ni 2P/SiO2) at a medium pressure of 0.5 MPa. The temperature dependency of the catalyst activity was determined and it was found that at 350 C Ni2P/SiO2 showed 100% conversion and 85% selectivity to n-pentane, with higher oxygen removal activity and less CC bond cracking activity than commercial noble metal Ru/C and Pd/Al2O3 catalysts based on the same amount of active sites. A contact time study allowed the determination of a reaction sequence for 2-MTHF HDO on Ni 2P/SiO2 and it was found that CO bond cleavage of the furanic ring to generate either 2-pentanone or 1-pentanal was the rate-determining step. This was followed by hydrogen transfer steps to produce oxygen free compounds, n-pentane or n-butane. A partial pressure analysis of 2-MTHF and H2 was consistent with a rate equation derived using a Langmuir-Hinshelwood (L-H) mechanism. This suggested that adsorption of 2-MTHF and hydrogen occurred competitively and that these species reacted on the Ni2P/SiO2 surface. Although high partial pressure of H2 was favorable for hydrogenation, too much H2 competed with 2-MTHF adsorption, which caused lower conversion.
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U2 - 10.1016/j.jcat.2013.11.002
DO - 10.1016/j.jcat.2013.11.002
M3 - Article
AN - SCOPUS:84890283047
SN - 0021-9517
VL - 311
SP - 17
EP - 27
JO - Journal of Catalysis
JF - Journal of Catalysis
ER -