Impact of ball-milling and ionic liquid pretreatments on pyrolysis kinetics and behaviors of crystalline cellulose.

In this work, the kinetic mechanisms of pyrolysis of cellulose with different physical structures were illustrated. The crystalline cellulose showed better thermal stability and required higher energy for decomposition with more concentrated reactions due to the highly ordered structure. The crystallinity of the ball milling and ionic liquid pretreated cellulose decreased and the structure was relatively loose and disordered, thereby reducing the thermal stability, so the global activation energy of both samples decreased and the intensive reaction caused by the collapse of structure was alleviated. In fast pyrolysis, crystalline cellulose favored fast pyrolytic saccharification, and the highest levoglucosan yield reached 64.3 wt% at 400 °C. This research was helpful to deduce the influence of physical structure on the pyrolytic product distribution of cellulose, thereby providing useful information to promote the development of pyrolytic saccharification.