Recent Advances in the Catalytic Conversion of Biomass to Furfural in Deep Eutectic Solvents

Abstract

Lignocellulose is recognized as an ideal raw material for biorefinery as it may be converted into biofuels and value-added products through a series of chemical routes. Furfural, a bio-based platform chemical generated from lignocellulosic biomass, has been identified as a very versatile alternative to fossil fuels. Deep eutectic solvents (DES) are new “green” solvents, which have been employed as green and cheap alternatives to traditional organic solvents and ionic liquids (ILs), with the advantages of low cost, low toxicity, and biodegradability, and also have been proven to be effective media for the synthesis of biomass-derived chemicals. This review summarizes the recent advances in the conversion of carbohydrates to furfural in DES solvent systems, which mainly focus on the effect of adding different catalysts to the DES system, including metal halides, water, solid acid catalyst, and certain oxides, on the production of furfural. Moreover, the challenges and perspectives of DES-assisted furfural synthesis in biorefinery systems are also discussed in this review.

Tetrabutylammonium-chloride-glycerol of deep eutectic solvent functionalized MnO2: a novel mimic enzyme for the quantitative and qualitative colorimetric detection of l-cysteine

“…Deep eutectic solvent (DES), as an emerging solvent, has been identified as offering new possibilities to replace traditional solvents in the field of organic and material synthesis, 18,19 separation, 20 electrochemistry, 21 and so on. DES is made of hydrogen-bond acceptors (HBAs) and hydrogenbond donors (HBDs) in a proper ratio under certain conditions.…”

“…22 Generally, choline chloride, betaine, quaternary ammonium/phosphonium salts, and amino acid are mainly considered as HBAs, while glycerol, ethylene glycol, polymer, carbohydrates, carboxylic acids, and urea are regard as HBDs. [23][24][25] Its unique composition can be tuned to design the DES to obtain specific properties, so it is often used as a functional monomer to functionalize various nanomaterials, for example metal-organic frameworks, 19 graphene oxide, 26 silica microspheres, 27 carbon dots. 28 From the above reported literature, it is known that the properties of nanomaterials can be promoted and improves by the introduction of DES.…”

Synthesis of biofuel precursors from benzaldehyde and cyclopentanone via aldehyde–ketone condensation in a deep eutectic solvent system

“…The global energy demand, which is anticipated to exceed 28% by 2040, imperatively necessitates the development of more renewable biofuels, such as bio-jet fuels, bioethanol, biobutanol and biodiesel, etc. [1][2][3] Sustainable liquid biofuels (SLB) attained from biomass-derived platform compounds (BDPC) have drawn tremendous attention due to the concerns of the energy crisis and the goals of "carbon peaking" and "carbon neutrality". [4][5][6] With the advantages of renewability, low toxicity, low sulfur content, biodegradability and high-octane number, SLB can serve as a promising alternative fuel to fossil fuels to be compatible with existing engines for different applications.…”

“…1,6,[28][29][30] DESs prepared by coupling choline chloride (ChCl) and carboxylic acids have been found to be an exceptional alternative to convert BDPC into biofuel precursors. 3,31 In addition, metal chlorides (NiCl 2 , CrCl 3 , SnCl 4 , etc.) were reported to have a cooperative effect with DESs to act as the aldose isomerization and condensation reactions of BDPC.…”

“…15,22 Furthermore, the actual applications for developing renewable biofuels from BDPC are restricted due to the complex separation, difficult recovery, corrosion of equipment and environmental pollution by effluent of these catalysts. 1,3,22 Thus, the green and high-efficiency catalysts are imperatively desired as a prerequisite for the synthesis of biofuels.…”