The degradation and saccharification of microcrystalline cellulose in aqueous acetone solution with low severity dilute sulfuric acid

Hydrolysis properties of microcrystalline cellulose (MCC) in different aqueous polar aprotic solvents with low severity sulfuric acid were compared. Comparing to other polar aprotic solvents, acetone had better performance in hydrolysis of MCC. The effects of reaction conditions on the degradation and saccharification of MCC were investigated. The results indicated some glucose was converted to fructose by isomerization during the degradation process, but fructose was more easily degraded to by-products in subcritical system, which resulted in the decline of saccharification yield. After MCC was treated with 80 wt% acetone solution with 0.1 wt% H₂SO₄, solid-liquid ratio of 1:10 (g/g) at 180 °C for 60 min, its weight loss rate and saccharification yield could achieve 58% and 71%, respectively The specific surface area of MCC increased in this process, although the crystallinity index of cellulose increased. Furthermore, 72.9% of levulinic acid and almost all of the HMF and furfural in the hydrolysate could be extracted by ethyl acetate. Remarkably, the recovered sugars could be used as the carbon source for succinic acid production.