Catalytic Fast Pyrolysis of Cellulose to Prepare Levoglucosenone Using Sulfated Zirconia

Graphical It′s not diamond, it′s zirconia: SO 4 2− /ZrO 2 is an efficient catalyst for the production of levoglucosenone by fast pyrolysis of cellulose admixing catalysts. The optimal temperature for preparation of levoglucosenone is in the range of 320–350 °C. In the presence of the SO 4 2− /ZrO 2 , the levoglucosenone content of pyrolysis liquid is greatly increased at 335 °C compared to pure cellulose. Sulfated zirconia was employed as catalyst for fast pyrolysis of cellulose to prepare levoglucosenone (LGO), a very important anhydrosugar for organic synthesis. The yield and the selectivity of LGO were studied in a fixed-bed reactor at different temperatures and cellulose/catalyst mass ratios. The experiments of catalyst recycling were also carried out. The results displayed that from 290 to 400 °C, the liquid and solid accounted for more than 95 wt % of products, and the higher temperature led to more liquid and less solid products. The introduction of SO 4 2− /ZrO 2 could promote cellulose conversion and LGO production. The temperature had a similar effect on the yield and selectivity of LGO at different cellulose/catalyst mass ratios. The maximum yield was obtained at 335 °C. Although the structure of the parent ZrO 2 was retained after recycles, which was confirmed by X-ray diffraction and N 2 adsorption–desorption measurements, the activity of SO 4 2− /ZrO 2 could only be partially recovered by simply calcination. The catalytic activity decrease could be mainly attributed to SO 4 2− leaching, and the activity could be restored by further impregnation of H 2 SO 4 .