Catalytic Fast Pyrolysis of Cellulose to Prepare Levoglucosenone Using Sulfated Zirconia

• Published in: ChemSusChem 2011-01, Vol.4 (1), p.79-84
• Main Authors: Wang, Zhi, Lu, Qiang, Zhu, Xi-Feng, Zhang, Ying
• Format: Article
• Language: English
• Subjects: biomass; Bridged Bicyclo Compounds, Heterocyclic - chemistry; carbohydrates; Catalysis; Cellulose - chemistry; Glucose - analogs & derivatives; Glucose - chemistry; heterogeneous catalysis; Kinetics; pyrolysis; Sulfuric Acids - chemistry; Temperature; zirconium; Zirconium - chemistry
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201000210

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 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 °C. Although the structure of the parent ZrO2 was retained after recycles, which was confirmed by X‐ray diffraction and N2 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. It′s not diamond, it′s zirconia: SO42−/ZrO2 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 SO42−/ZrO2, the levoglucosenone content of pyrolysis liquid is greatly increased at 335 °C compared to pure cellulose.