Selective Microwave-Assisted Pyrolysis of Cellulose towards Levoglucosenone with Clay Catalysts

Levoglucosenone (anhydrosugar) is one of the most promising chemical platforms derived from the pyrolysis of biomass. It is a chiral building block for pharmaceuticals as well as an intermediate in the production of solvents and polymers. Therefore, the development of cost-efficient, low-energy production methods is vital for a future sustainable biorefinery. Here, a novel, green approach to the production of levoglucosenone was developed by using a microwave (MW)-assisted pyrolysis of cellulose in the presence of readily available clays. It was shown that natural and pillared clays in the presence of MW irradiation significantly increase the yield of levoglucosenone from cellulose. Both the water content and the presence of acid centres are critical characteristics that influence the yield and distribution of catalysed products. A unique experiment was designed by using a synergetic effect between different types of catalysts, which enhanced the levoglucosenone yield to 12.3 wt % with 63 % purity.