Catalytic Conversion of Biomass to Furanic Derivatives with Deep Eutectic Solvents

Abstract

Biomass is the only renewable organic carbon resource in nature, and the transformation of abundant biomass into various chemicals has received immense spotlight. As a novel generation of designer solvents, deep eutectic solvents (DESs) have been widely used in biorefinery due to their excellent properties including low cost, easy preparation, and biodegradability. Although there have been some reports summarizing the performance of DESs for the transformation of biomass into various chemicals, few Reviews illuminate the relationship between the functional structure of DESs and catalytic conversion of biomass. Hence, this Minireview comprehensively summarizes the effects of the types of functional groups in DESs on catalytic conversion of biomass into furanic derivatives, such as carboxylic acid-based hydrogen-bond donors (HBDs), carbohydrate-based HBDs, polyalcohol-based HBDs, amine/ amide-based HBDs, spatial structure of HBDs, and various hydrogen-bond acceptors (HBAs). It also further summarizes the effects of adding different additives into the DESs on the synthesis of high value-added chemicals, including water, liquid inorganic acids, Lewis acids, heteropoly acids, and typical solid acids. Moreover, current challenges and prospects for the application of DESs in biomass conversion are provided.

Mini-Review on the Synthesis of Furfural and Levulinic Acid from Lignocellulosic Biomass

“…over ionic liquids [37]. Many researchers reported that DESs can act as reaction mediums and provide Brønsted acidity to convert biomass into furfural [38]. Choline chloride-oxalic acid-based DESs were used as a solvent and a catalyst to produce furfural with a 26.3% yield from oil palm fronds at 100 • C for 135 min [39].…”

Phosphoric acid-modified commercial kieselguhr supported palladium nanoparticles as efficient catalysts for low-temperature hydrodeoxygenation of lignin derivatives in water

“…With growing concerns over energy reserves and climate change, utilization of renewable lignocellulosic biomass to produce high value-added chemicals and liquid biofuels is considered a promising alternative route not only to reduce over-dependence on fossil resources but also to meet with the development of economy and society. [1][2][3][4][5][6] Lignocellulosic biomass consists of three main components: 30-50% of cellulose, 20-35% of hemicellulose, and 15-30% of lignin. Among them, lignin with aromatic monomers in its structure is the only scalable renewable feedstock which can be converted to valuable aromatic chemicals.…”

Enhanced Furfural Production in Deep Eutectic Solvents Comprising Alkali Metal Halides as Additives

“…From the different chemicals that can be obtained from renewable resources, furfural is among the most relevant, with a world market of around 300,000 tons per year, while being identified by the US Department of Energy (DOE) as one of the top 12 value-added chemicals attained from biomass [ 4 ]. This compound is a precursor of other essential chemicals that are intermediates and/or solvents in industry, such as 2-methyltetrahydrofuran (2-Me-THF), furan, tetrahydrofuran (THF) and 2-methylfuran [ 5 ].…”

“…These issues are mainly attributed to the nature of the catalysts. Acidic catalysts can cause the formation of side products such as humins, resulting from furfural condensation, while heterogeneous catalysts display low accessibility to biomass [ 5 ].…”

“…These neoteric solvents are low-temperature melting salts due to their ionic nature present negligible vapor pressure, outstanding chemical and thermal stability, and extended solvation ability [ 20 ]. ILs have been shown to display an important role in the synergistic transformation of biomass into chemicals [ 5 ]. In particular, ILs have shown promising results in the dehydration of furfural, either as reaction media [ 21 ] or as catalysts [ 22 ].…”