ABSTRACT
This work reports a high-yielding synthesis of γ-butyrolactone (GBL), a promising biofuel, renewable solvent, and sustainable chemical feedstock, by the catalytic hydrogenation of 2-furanone. 2-Furanone can be synthesized renewably by the catalytic oxidation of xylose-derived furfural (FUR). Humin, produced during the preparation of FUR from xylose, was carbonized to form humin-derived activated carbon (HAC). Palladium supported on humin-derived activated carbon (Pd/HAC) was used as an efficient and recyclable catalyst for hydrogenating 2-furanone into GBL. The process was optimized in various reaction parameters, such as temperature, catalyst loading, hydrogen pressure, and solvent. Under optimized conditions (RT, 0.5 MPa H2, THF, 3 h), the 4% Pd/HAC (5 wt% loading) catalyst afforded GBL in an 89% isolated yield. Under identical conditions, an 85% isolated yield of γ-valerolactone (GVL) was obtained starting from biomass-derived angelica lactone. Moreover, the Pd/HAC catalyst was conveniently recovered from the reaction mixture and successfully recycled for five consecutive cycles with only a marginal decrease in the yield of GBL.
ABSTRACT
Furfural has been produced in 53% isolated yield from d-xylose within an aqueous HCl-1,2-dichloroethane biphasic reaction mixture using benzyltributylammonium chloride (BTBAC) as a phase transfer catalyst. The use of BTBAC noticeably improved the yield of furfural compared to that in the control reaction. The reaction was optimized on the reaction temperature, duration, concentration of HCl, and the loading of BTBAC. Furfural and 5-(chloromethyl)furfural (CMF) have also been coproduced from a mixture of pentose and hexose sugars. Under optimized conditions (100 °C, 3 h, 20.2% HCl, 10 wt% BTBAC), CMF and furfural were isolated in 17% and 53% yield, respectively, from a mixture of glucose and xylose. In addition, levulinic acid was isolated from the aqueous layer in 31% yield.
