Catalytic Fast Pyrolysis of Cellulose to Prepare Levoglucosenone Using Sulfated Zirconia

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 degrees 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 SO42-/ZrO2 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 degrees C. Although the structure of the parent ZrO2 was retained after recycles, which was confirmed by X-ray diffraction and N-2 adsorption-desorption measurements, the activity of SO42-/ZrO2 could only be partially recovered by simply calcination. The catalytic activity decrease could be mainly attributed to SO42- leaching, and the activity could be restored by further impregnation of H2SO4.