Effect of Water Content on Conversion of d-Cellobiose into 5-Hydroxymethyl-2-furaldehyde in a Dimethyl Sulfoxide–Water Mixture

Abstract

Noncatalytic conversion of D-cellobiose (at 0.5 M) into 5-hydroxymethyl-2-furaldehyde (5-HMF), a platform chemical for fuels and synthetic materials, was analyzed at 120-200 °C over a wide range of water mole fraction, xw = 0.007-1 in a binary dimethyl sulfoxide (DMSO)-water mixture by means of the in situ (13)C NMR spectroscopy. Effects of the water content were revealed as follows: (i) The tautomerization of the anomeric residue of D-cellobiose from D-glucose to D-fructose type was not initially observed at a lower water content, in contrast to the significant tautomerization into the D-fructose type in a higher water content and pure water. (ii) The lower the water content, the faster the glycosidic-bond cleavage by hydrolysis, because of the high reactivity of solitary water molecules with the large partial charges more naked as in supercritical water clusters due to the isolation by the organic solvent DMSO. (iii) The amount of D-fructose as the intermediate product was larger at the higher xw; despite the increase of D-fructose, the production of 5-HMF from D-fructose was slowed down. (iv) A high 5-HMF yield of 71% was reached at xw = 0.20-0.30 that was 6-10 times the initial D-cellobiose concentration. The best yield of 5-HMF was attained in the low xw region when the polymerization paths into NMR-undetectable species via 5-HMF and anhydromonosaccharides were effectively suppressed. This study provides a new framework to design optimal, noncatalytic reaction process to produce 5-HMF from cellulosic biomass by tuning the water content as well as the temperature and the reaction time.

Organic Carbonates: Efficient Extraction Solvents for the Synthesis of HMF in Aqueous Media with Cerium Phosphates as Catalysts

“…Disaccharides (sucrose [29] and cellobiose [30] ), polysaccharides (inulin [31] ), and even cellulose itself [32] can be used as starting materials, the latter after depolymerization. Disaccharides (sucrose [29] and cellobiose [30] ), polysaccharides (inulin [31] ), and even cellulose itself [32] can be used as starting materials, the latter after depolymerization.…”

“…Disaccharides (sucrose [29] and cellobiose [30] ), polysaccharides (inulin [31] ), and even cellulose itself [32] can be used as starting materials, the latter after depolymerization. Extensive research is currently underway to develop efficient, cheap, and sustainable commercial methods for the preparation of 5-HMF.…”

Influence of Water-Miscible Organic Solvent on the Activity and Stability of Silica-Coated Ru Catalysts in the Selective Hydrolytic Hydrogenation of Cellobiose into Sorbitol

“…The best-performing covered catalyst, namely Ru/CB@SiO 2 (P), was finally tested in a model reaction of cellulose valorization: the catalytic transformation of cellobiose into sorbitol in one pot. Kinetic modeling has shown that hydrolysis is the rate-limiting step for the hydrolytic hydrogenation of cellobiose (or cellulose) to sorbitol (110-115 KJ/mol for the hydrolysis of cellobiose) [19,40]. Therefore, this step is a highly demanding reaction that usually requires strong acid sites irrespective of the reaction pathway to produce sorbitol, as shown in Figure 4.…”

“…For instance, Mellmer et al have shown that the rate of cellobiose hydrolysis is strongly improved by using γ-valerolactone as solvent compared to conversion in aqueous media [18]. More recently, it has been proven that by tuning the water content in dimethyl sulfoxide, as well as the temperature and the reaction time, it is possible to perform a non-catalytic conversion of cellobiose into 5-hydroxymethyl-2-furaldehyde [19]. In addition to the solvent nature in which the catalytic reaction is carried out, it has been also proven that the mesoporous silica material type, and indirectly some parameters such as the wall thickness, have a great influence on the material hydrothermal stability [7].…”

A novel route towards high yield 5-hydroxymethylfurfural from fructose catalyzed by a mixture of Lewis and Brönsted acids

“…So far, it is well known that some polar aprotic solvents like dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), and 1,4-dioxane are the most favourite solvents for the dehydration of fructose because they have considerable solubility to fructose and can inhibit the decomposition of 5-HMF to levulinic acid as occurred in the presence of water and other protic solvents. 5,[7][8][9] The application of imidazolium-based ionic liquids and other deep eutectic mixtures as dual acid catalyst and solvent may be the most effective strategy for the dehydration of fructose as well as other carbohydrates. 4,[10][11][12] However, their high boiling points and excellent miscibility with 5-HMF bring a huge challenge to the post-separation of 5-HMF from the reaction bulk, which seems less feasible for industrialization even though much progress has been made in the separation of 5-HMF from ionic liquids.…”