Pretreatment-assisted catalytic pyrolysis for enhanced levoglucosenone production from waste cellulose acetate

This study developed an innovative method for directional degradation and valorization of waste cellulose acetate (CA) through pretreatment followed with catalytic pyrolysis, enabling the efficient and high-value recovery of CA. A synergistic pretreatment with ethanol and NaOH was employed to modify the molecular structure of CA feedstock. Coupled with phosphoric acid-activated carbon (PAC) catalyzed pyrolysis, the pretreatment-dependent alternation in CA’s physicochemical properties and their effects on pyrolysis to prepare levoglucosenone (LGO) were systematically investigated. The results indicated that the ethanol-NaOH synergistic pretreatment selectively removed the acetyl substituents in CA, exposing more cellulose characteristics, and facilitated the swelling of CA. These modifications enhanced the suitability of CA for selective LGO production. In pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments, the highest yield of LGO from pretreated CA reached 17.84 wt%, significantly exceeding the 2.67 wt% yield gained from untreated CA. This study laid a solid foundation for the efficient and high-value recycling of waste CA.