Glucose Production from Cellulose via Selective Hydrolysis in Molten Salt Hydrate

To address the challenges of the unclear mechanism of cellulose dissolution and hydrolysis in molten salt hydrate(MSH?. This work systematically studied the hydrolysis of cellulose in molten salts hydrate consisting of different cations(e.g.? Li+? Na+? K+? Zn2+ ?? and anions(e.g.? Cl-? Br- and I-?? and screened the best molten salt for cellulose hydrolysis? LiBr? and studied the effect of acidity on cellulose hydrolysis. The result indicated that the<br />limited solubility of the cation Na+ and K+ resulted in the insufficient coordination between cations and oxygen atoms in the cellulose? which cannot provide sufficient Lewis acidity for glycosidic bonds cleavage. Additionally? the anion Cl- in MSH has limited electronegativity? which cannot form massive hydrogen bonds with the hydroxyl groups in cellulose? resulting in a limited solubility and thereby caused negative effect on hydrolysis. Under the reaction conditions of 130 celcius and 5 h in a non-acidified system? cellulose can be selectively hydrolyzed into water-soluble<br />oligosaccharides and glucose with the yield of 57.2% and 29.0%? respectively. The results also show that the MSH can catalyze the cleavage of cellulose glycoside bonds and decrease the cellulose degree of polymerization(DP? in an 0.01%(HCl? dilute acidic MSH at 100 celcius for 30 min ranging from 4 and 13. Improvement of acidity can enhance the cleavage efficiency of glycosidic bond cleavage. When the acidity increased to 0.1%(HCl?? a high yield of glucose at 90.9% can be achieved at 100 celcius for 30 min.