Highly efficient microwave driven assisted hydrolysis of cellulose to sugar with the utilization of ZrO2 to inhibit recrystallization of cellulose

Following the main idea of a two-step method, microcrystalline cellulose is firstly pretreated to prepare regenerated cellulose (RC) with low crystallinity. Then, RC is continuously hydrolyzed to sugar in aqueous system by microwave driving. With the establishment of ZrO2 contained low acid catalytic system, an advanced route driven by microwave radiation to induce highly efficient hydrolysis of RC to sugar is formed. Due to the effect of ZrO2 on the molecular chain of cellulose, the recrystallization of RC is obviously weakened, and higher hydrolysis reactivity is achieved. Under the optimal conditions, the average conversion of RC and the yield of total reducing sugar highly reach 98.4 +/- 0.5% and 97.9 +/- 0.6%, respectively. The result is extremely superior to the efficiency of hydrolysis initiated only by pure acid. As a result, a novel and simple thinking to establish an advanced two-step methodology to hydrolyze cellulose to sugar with high efficiency is achieved.