Selectively catalytic hydrolysis of fine fiber to produce glucose by solid acid catalyst in a molten salt system

<p indent="0mm">Glucose, a vital chemical feedstock, can be produced through the catalytic hydrolysis of renewable cellulose. Most recently, researchers have identified solid acid catalysts as promising candidates for the hydrolysis of low degree of polymerization (DP) microcrystalline cellulose to glucose because solid acid catalysts are favored for the great recyclability, ease separation, and low corrosiveness. However, it is difficult for the hydrolysis of high DP cellulose due to the solid-solid reactions, resulting in low hydrolysis efficiency of cellulose. In view of the good solubility of cellulose in molten salt hydrates such as LiBr∙3H₂O, this work investigated the hydrolysis of fine fibers (DP=961) catalyzed by solid catalysts coupled with the molten salt hydrates. The physicochemical characteristics of different solid acid catalysts were compared, and the synergistic effects of solid acid catalysts combined with a LiBr∙3H₂O molten salt system was explored for the hydrolysis of fine fibers. The results show that the HZSM-5 solid acid coupled with LiBr∙3H₂O molten salt system exhibits excellent catalytic performance, achieving a high glucose yield, where a glucose yield of 70.43% was obtained at <sc>129 °C</sc> after <sc>243 min</sc> of hydrolysis. This research provides a new route for the efficient preparation of glucose from the hydrolysis of natural cellulose.