Roles of Ball Milling Pretreatment and Titanyl Sulfate in the Synthesis of 5-Hydroxymethylfurfural from Cellulose

Abstract

Production of 5-hydroxymethylfurfural (HMF) from cellulose has been expected for a long time, but most catalytic systems generally give low yield and selectivity due to the difficulty of balancing cellulose deconstruction with the uncontrollable degradation of the target product under harsh conditions. Here we show that the ball milling pretreatment could markedly facilitate the conversion of microcrystalline cellulose to HMF by titanyl sulfate (TiOSO 4 ). The ball milling pretreatment remarkably decreases the degree of crystallinity of microcrystalline cellulose with a reduction of molecular weight via disrupting the hydrogen bond and partially breaking the β-1,4-glycosidic bond. TiOSO 4 functions as both Lewis and Brønsted acid to catalyze the efficient conversion of cellulose with high HMF yield (45.4%), far exceeding that (14.1%) from untreated cellulose. The reaction pathway was revealed by liquid chromatograph−mass spectra analysis. In addition, phosphorylated titanium dioxide also afforded a notable HMF yield (21.8%), showcasing the great potential of Ti-based heterogeneous catalyst.

Conversion of Cellulose into 5-Hydroxymethylfurfural in a Biphasic System Catalyzed by Aluminum Sulfate and Byproduct Characterization

“…In the biphasic system, the conversion of cellulose into HMF is carried out in the aqueous phase, and the formed HMF is extracted from the aqueous phase into the organic phase to suppress its further degradation. Diverse organic solvents, especially polar aprotic solvents such as tetrahydrofuran (THF), − methyl isobutyl ketone (MIBK), − and γ-valerolactone (GVL), − are frequently employed as organic extraction solvents in the biphasic system for HMF production. Among these organic solvents, both GVL and THF are biomass-derived green solvents, but the high boiling point of GVL (207 °C) makes the separation of HMF and the recycling of GVL difficult .…”

“…Diverse organic solvents, especially polar aprotic solvents such as tetrahydrofuran (THF), − methyl isobutyl ketone (MIBK), − and γ-valerolactone (GVL), − are frequently employed as organic extraction solvents in the biphasic system for HMF production. Among these organic solvents, both GVL and THF are biomass-derived green solvents, but the high boiling point of GVL (207 °C) makes the separation of HMF and the recycling of GVL difficult . Compared with GVL, THF has the advantage of easy recovery because of its low boiling point of 66 °C. , Besides, impressive HMF yields of 40–70% from cellulose have been achieved in the H 2 O–THF biphasic system, − making the H 2 O–THF reaction system promising for the commercial production of HMF from biomass.…”

“…In contrast, using commercially available acidic metal salts and mineral acids as catalysts would be more promising for the large-scale production of HMF. Several acidic metal salts such as AlCl 3 , FeCl 3 , InCl 3 , TiOSO 4 , NaHSO 4 , and Al 2 (SO 4 ) 3 have been reported to catalyze the conversion of cellulose into HMF with low yields in the range of 35–55%. ,,− ,− Besides, a low HMF yield of 44% was obtained by the H 2 SO 4 -catalyzed conversion of cellulose in THF in the presence of 2–3 vol % water. , …”

Sulfonic acid functionalized dendrimer-grafted cellulose as a solid acid catalyst for the high-yield and green production of 5-hydroxymethylfurfural

“…3,4 Among them, 5-hydroxymethylfurfural (5-HMF) is manufactured by acid-catalyzed carbohydrate dehydration, 5 and has been used successfully as a key biorening intermediate for the synthesis of highperformance liquid fuels and ne chemicals. 6,7 Other derivatives of 5-HMF, such as levulinic acid, 2,5-dimethylfuran, and 2,5-furandicarboxylic acid, are also considered to be valuable fuel additives. 8 Several types of acidic catalysts have been explored for carbohydrate dehydration to 5-HMF, ranging from homogeneous catalysts (e.g.…”

Regulating the Alkalinity of Carbon Nitride by Magnesium Doping to Boost the Selective Isomerization of Glucose to Fructose

“…Growing concerns over environmental issues are incentives to search for renewable resources. , Lignocellulosic biomass is one of the most ambitious renewable resources that has the promise of reducing the emission of carbon dioxide. , Therefore, considerable endeavors have been devoted to the production of fine chemicals, liquid fuels, and degradable materials from biomass . The conversion of biomass to value-added products require a series of reactions, including the saccharification of starch and cellulose to glucose, isomerization of glucose to fructose, dehydration of sugars to 5-hydroxymethylfurfural (HMF), and upgradation of HMF to polymer precursors, fine chemicals, liquid fuels and other platform chemicals. − Since the dehydration of fructose to HMF and the cascade conversion of fructose to high-value HMF derivatives are considerably easier than the conversion of glucose and its polymer, the effective isomerization of glucose to fructose is considered as a prerequisite for the facile valorization of biomass to these target products. , …”