TY - JOUR
T1 - Catalytic hydrogenation of levulinic acid in ionic liquid mixtures using hydrogen gas in high-pressure CO2
AU - Guo, Haixin
AU - Tomoka, Shida
AU - Smith, Richard Lee
N1 - Funding Information:
The authors are grateful to the financial supports from the JSPS Grant in Grant-in-Aid for Early-Career Scientists (No. 19K15347, Japan ) and the project program of Tohoku university center for gender equality promotion.
Publisher Copyright:
© 2020 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in ionic liquid (IL) mixtures with hydrogen gas in high-pressure CO2 was studied to demonstrate tuning of product selectivity. Ethyl- or butyl- imidazolium-based cation with Cl, acetate [OAc], diethylphosphate, bis(trifluoro-methanesulfonyl)imide or tetrafluoroborate anion IL mixtures were used as the reaction phase with Pd/C, Pd/Al2O3 or Ru/Al2O3 commercial catalysts. Experiments were performed with batch reactors using (1 to 5) MPa partial pressure H2 at nominal pressures of 8 MPa at 110 °C. GVL selectivities as high as 88% at 50% conversion were obtained in [EMIM]Cl-[EMIM][OAc] using 3 MPa partial pressure H2 in presence of CO2 at 4 h reaction time. Specific interactions of LA with Cl anion IL and CO2 with [OAc] anion IL are key to the reaction mechanism. Reaction systems containing Cl anion - [OAc] anion IL mixtures with H2 gas and CO2 have wide application to hydrogenation of biomass-related compounds.
AB - Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in ionic liquid (IL) mixtures with hydrogen gas in high-pressure CO2 was studied to demonstrate tuning of product selectivity. Ethyl- or butyl- imidazolium-based cation with Cl, acetate [OAc], diethylphosphate, bis(trifluoro-methanesulfonyl)imide or tetrafluoroborate anion IL mixtures were used as the reaction phase with Pd/C, Pd/Al2O3 or Ru/Al2O3 commercial catalysts. Experiments were performed with batch reactors using (1 to 5) MPa partial pressure H2 at nominal pressures of 8 MPa at 110 °C. GVL selectivities as high as 88% at 50% conversion were obtained in [EMIM]Cl-[EMIM][OAc] using 3 MPa partial pressure H2 in presence of CO2 at 4 h reaction time. Specific interactions of LA with Cl anion IL and CO2 with [OAc] anion IL are key to the reaction mechanism. Reaction systems containing Cl anion - [OAc] anion IL mixtures with H2 gas and CO2 have wide application to hydrogenation of biomass-related compounds.
KW - Biomass
KW - Hydrogen solubility
KW - Hydrogenation reaction
KW - Mixed ionic liquids
KW - Supercritical carbon dioxide
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U2 - 10.1016/j.supflu.2020.104891
DO - 10.1016/j.supflu.2020.104891
M3 - Article
AN - SCOPUS:85085310579
VL - 164
JO - Journal of Supercritical Fluids
JF - Journal of Supercritical Fluids
SN - 0896-8446
M1 - 104891
ER -