Tandem Conversion of Fructose to 2,5-Dimethylfuran with the Aid of Ionic Liquids

Abstract

Biomass-derived 2,5-dimethylfuran (DMF) is an ideal, renewable gasoline additive, and its production with high productivity is highly desirable. A continuous production route was developed to yield DMF from fructose via a tandem strategy, where dehydration catalysts (HY zeolite and niobium phosphate) assisted by 1-butyl-3-methylimidazolium chloride ([BMim]Cl) and hydrodeoxygenation (HDO) catalyst Cu−Ru/C were integrated into one reaction system with γ-butyrolactone (GBL) as the mobile phase. Optimum conditions, such as temperature, H 2 pressure, weight hourly space velocity, and [BMim]Cl concentration, were investigated systematically, with an initial HDO study by using 5hydroxymethylfurfural (HMF) as substrate and subsequent tandem dehydration and HDO to produce DMF with fructose as substrate. Among the conditions, the highest yield of DMF at 55.2% was gained by niobium phosphate and Cu−Ru/C, with the aid of [BMim]Cl in a fixed bed. Meanwhile, [BMim]Cl facilitated fructose dehydration to HMF and also mediated HDO of the resultant HMF by stabilization, which was clarified by 1 H NMR and FTIR spectroscopy. Finally, the fact that carbon deposit led to catalyst deactivation was examined thoroughly via a series of characterization techniques. This work achieved continuous DMF production from fructose and laid a foundation for future possible amplification of DMF.

Advances of Ionic Liquids and Deep Eutectic Solvents in Green Processes of Biomass‐Derived 5‐Hydroxymethylfurfural

“…Recently, Zhu et al. performed HMF hydrogenation in a fixed bed, affording a high DMF yield of 75.2 % using Cu−Ru/C as catalyst under optimum conditions of 180 °C, H 2 pressure of 5 MPa with flow rate of 30 mL min −1 , 3 wt % HMF, and 10 wt % [BMIm]Cl in γ‐butyrolactone with flow rate 0.01 mL min −1 [106] . Furthermore, they developed a tandem strategy to continuously generate DMF directly from fructose.…”

2D MOF with Compact Catalytic Sites for the One‐pot Synthesis of 2,5‐Dimethylfuran from Saccharides via Tandem Catalysis

“…Early experiments proposed a two-step method containing dehydration of fructose to 5-HMF with a yield of approximately 80 % at 130-150 °C and subsequent hydrodeoxygenation with a overall 2,5-DMF yield of 20-50 % at 150-220 °C over a mixture of acid and metal catalysts (e.g., ZnCl 2 + Pd/C and acidic ionic liquid + Ru/C). [8,[13][14][15] Unfortunately, the two-step reaction systems suffered from long reaction time, low 2,5-DMF yield, and corrosivity of homogeneous acids. Subsequently, several solid acid-supported metal catalysts (e.g., Pd/UiO-66 + C-SO 3 H, Pd/UiO-66@sulfonated graphene oxide, and Pd/Cr-MIL-101-SO 3 H) were developed for the one-pot upgrading of fructose to 2,5-DMF at 150-220 °C.…”

Ionic Liquids as a Sustainable Platform for Nanocellulose Processing from Bioresources: Overview and Current Status

“…ILs are a group of salts composed of cations and anions, and they are liquids at ambient temperature. The unique and attractive physicochemical properties of ILs such as high solvation ability to dissolve various biopolymers, prominent thermal and chemical stability, and extremely low vapor pressure make them promising candidates to replace traditional cellulose processing solvents/agents. − The two important advantages of using ILs in NC processing over conventional techniques include the promising solvent recovery with minimum loss and can be reused many times. For example, more than 90% of IL [Bmim]­[Cl] (1-butyl-3-methylimidazolium chloride) was recovered and reused four times without losing its activity .…”