Selective conversion of starch to glucose using carbon based solid acid catalyst

Activated carbon supported silicotungstic acid is used as catalyst for the hydrolysis of starch to glucose. The selectivity of the hydrothermal process for glucose production is demonstrated. Byproducts such as levulinic and formic acids are not formed. Separation of the catalyst is easy, and the catalyst reusability is demonstrated in five consecutive reaction runs. No appreciable loss in activity and selectivity of the catalyst is observed even after 5 consecutive reaction runs. Leaching of the heteropoly acid into the reaction medium is not observed. The yield of glucose (94 wt. %) is close to the theoretical yield (111 wt. %) possible from starch. Thus the glucose production process is atom efficient and green.