Enhanced Sugar Alcohol Production from Cellulose by Pretreatment with Mixed Ball-Milling and Solid Acids

Efficient pretreatment is the key step in catalytic biomass conversion. Herein, a mixed ball-milling method was used to pretreat cellulose with a solid catalyst. The method was tested with solid acid and commercial 5 wt% Ru/C in water, and the effect of pretreatment on yield was measured by the hydrolytic-hydrogenation of cellulose to sugar alcohols, which are the platform compounds for the production of gasoline and fine chemicals. The influence of ball-milling mode, time, and reaction parameters was studied. The properties of cellulose and the catalyst were also analyzed before and after treatment. The yield of sugar alcohols reached 90.3% at 463 K with amorphous zirconium phosphate (ZrP) and Ru/C and a mixed ball-milling time of 2 h. The high sugar alcohol yield was achieved 12 times faster than with the single ballmilling method under the same reaction conditions for 24 h. This effect is ascribed to the enhanced contact between cellulose and catalyst, which promotes the rate-determined cellulose depolymerization to obtain high sugar alcohols yield.