Production of water-soluble sugar from cellulose and corn stover via molten salt hydrate impregnation and separation

Research advancement in molten salt-mediated thermochemical upcycling of biomass waste

“…4a, the MSHs can be recovered and reused easily by centrifugation. Additionally, anti-solvents such as MeOH 54 and n -butanol 63 can be used to separate the glucan oligomers by precipitation. As shown in Fig.…”

Enhanced production and separation of short-chain glucan oligomers from corn stover in an unacidified LiBr molten salt hydrate via pre-extraction of hemicellulose

“…The concentration of glucan oligomers produced from cellulose hydrolysis is a critical factor in product separation, solvent reusability 35 and commercial application. 48 This work tried to enhance the glucan oligomer concentration via increasing the substrate concentration. The effect of pre-extraction on the glucan oligomer concentration was investigated.…”

Underlying Mechanisms on the Controlled Depolymerization of High-Loading Cellulose in Water Promoted by Cetyltrimethylammonium Bromide

“…Cellulose, the natural polymer of glucose units linked by β-1,4-glycosidic bonds, is one of the main components in lignocellulosic biomass. , Valorization of cellulose, typically by depolymerizing cellulose into poly-/oligo-/monosaccharides (oligosaccharides: 2–20 monosaccharide units; polysaccharides: 21–100 monosaccharide units) via hydrolysis and further converting into secondary platform chemicals (e.g., 5-hydroxylmethylfurfural (HMF), levulinic acid (LA), ethanol, lactic acid, etc. ), − represents a promising route in future lignocellulosic biorefineries. As such, the controllable depolymerization of cellulose to poly-, oligo-, and monosaccharides with a desired rate and polymerization degree (DP) is crucial to the tandem chemical conversions of cellulose to valuable chemicals.…”

“…29 Nevertheless, the depolymerization of cellulose was too slow, even under conditions of high temperatures of 433−473 K and the massive existence of acid catalysts for overcoming the high activation energy (113.0−180.0 kJ•mol −1 ). 25,30 Prior to cellulose depolymerization, the destruction of the recalcitrant crystalline structure of cellulose to an amorphous structure by destroying the original inter-/intramolecular hydrogen bonds within cellulose with a physical (e.g., ballmilling 31−33 ) or chemical pretreatment (e.g., ionic liquid (ILs), 34−36 deep eutectic solvent (EDSs), 37,38 or molten salt hydrates (MSHs)) 4,39 was proven to be an effective strategy for the subsequent rapid depolymerization of cellulose at a low temperature of <413 K and thus disfavored the repolymerization of oligo-/monosaccharides into humins (Scheme 1b). 40,41 However, Tyufekchiev et al 42 found that the ball-milled cellulose would undergo recrystallization during depolymerization in water, which decreased the kinetics of cellulose hydrolysis.…”

“…Prior to cellulose depolymerization, the destruction of the recalcitrant crystalline structure of cellulose to an amorphous structure by destroying the original inter-/intramolecular hydrogen bonds within cellulose with a physical (e.g., ball-milling − ) or chemical pretreatment (e.g., ionic liquid (ILs), − deep eutectic solvent (EDSs), , or molten salt hydrates (MSHs)) , was proven to be an effective strategy for the subsequent rapid depolymerization of cellulose at a low temperature of <413 K and thus disfavored the repolymerization of oligo-/monosaccharides into humins (Scheme b). , However, Tyufekchiev et al found that the ball-milled cellulose would undergo recrystallization during depolymerization in water, which decreased the kinetics of cellulose hydrolysis. Besides, the destroying of the whole hydrogen-bond network within cellulose by chemical pretreatment with ILs, EDSs, or MSHs was thought to efficiently lower the degree of crystallinity − but sharply enhance the local concentration of oligosaccharides on a cellulosic surface and disfavor the following mass transfer and conversion, especially at high substrate loading …”