Solvolysis kinetics of three components of biomass using polyhydric alcohols as solvents

- The solvolysis behaviors of three components of biomass were compared.
- The iso-conversional method was applied to estimate the apparent activation energies.
- The most probable mechanism functions were determined by the Malek method.
- The activated complex theory was applied to determine ΔS′, ΔH′ and ΔG′.

The solvolysis behavior and reaction kinetics of the three components of biomass (cellulose, hemicelluloses and lignin) liquefied in polyhydric alcohols (PEG 400 or glycerol) were investigated in this paper. Three stages were observed during the solvolysis process and the main degradation stage could be further divided into two zones. The influences of solvents on the liquefaction process of three main components were compared. Based on Starink and Malek methods, kinetic parameters and mechanism functions were obtained. The derived average activation energy of cellulose, hemicellulose and lignin were 108.73, 95.66 and 94.13 kJ mol−1 in PEG 400, while the values were 102.16, 77.43 and 89.10 kJ mol−1 in glycerol, respectively. Higher efficiency was observed when using glycerol as solvent, which could be ascribed to the higher polarity value of glycerol. The conversion curves calculated with obtained mechanism models and kinetic parameters were in good agreement with the experimental data.