Pyrolysis behavior and kinetics of grape pruning residues: Insights from multistep reaction models and Py-GC/MS

Grape pruning residue (GPR), a common type of agricultural waste, represents a missed opportunity for resource optimization if left unutilized. Pyrolysis offers a promising method to achieve the high-value utilization of GPR. The study of pyrolysis kinetics is crucial for understanding the pyrolysis behavior of GPR. In this research, the kinetic parameters of GPR were estimated using multistep reaction (MSR) model. The apparent activation energies (E_α) of hemicellulose, cellulose, and lignin were determined to be 166.034, 146.301, and 446.534 kJ/mol, respectively. The pre-exponential factors (A) were calculated as 9.790 × 10¹⁴, 4.836 × 10¹², and 6.712 × 10³³ s⁻¹, respectively. The reaction mechanism (f(α)) were expressed as f₁(α₁) = α₁^1.2258(1-α₁)^0.8011[-ln(1-α₁)]^−1.5723, f₂(α₂) = α₂^2.0985(1-α₂)^0.7386[-ln(1-α₂)]^−1.4410 and f₃(α₃) = α₃^1.3944(1-α₃)^3.6981[-ln(1-α₃)]^−6.9943, respectively. Finally, the fast pyrolysis behavior of GPR at 400℃, 600℃, and 800℃ was investigated using Py-GC/MS.