Catalytic Fast Pyrolysis of Cellulose and Biomass to Selectively Produce Levoglucosenone Using Activated Carbon Catalyst

Activated carbon (AC) prepared by chemical activation with H3PO4 (named AC-P) was employed for catalytic fast pyrolysis of cellulose and biomass to selectively produce levoglucosenone (LGO). The catalytic pyrolysis behaviors and product distributions were revealed via both analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale experiments. Moreover, the performance of AC-P catalyst was compared with previously reported strong acid catalysts and other ACs prepared by different activation methods. In addition, reusability and stability of the AC-P catalyst have been examined via recycling experiments. The results indicated that the AC-P catalyst was effective for selectively preparing LGO from both cellulose and biomass and performed better than other catalysts. Among the three biomass materials (pine wood, poplar wood, and bagasse), pine wood showed the best selectivity for producing LGO. The maximal LGO yields of 18.1 and 9.1 wt % were obtained from cellulose and pine wood, respectively, in Py-GC/MS experiments under a catalyst-to-feedstock ratio of 1:3 at 300 °C, whereas the lab-scale setup obtained the highest LGO yields of 14.7 and 7.8 wt % from cellulose and pine wood with selectivities of 76.3 and 43.0%, respectively, based on organic liquid products. Furthermore, granular AC-P catalyst exhibited good reusability and stability in the recycling experiments. Stable yields of LGO above 12.5 wt % from cellulose were obtained in six consecutive runs without any regeneration of the recycled granular AC-P catalyst.