Co-pyrolysis of rubber seed oil and industrial hemp stem: Asym2sig deconvolution, thermal behavior, synergistic reaction and kinetic

Abstract

Evaluation of Kinetic triplets and thermodynamics of the co-pyrolysis of industrial hemp stem (IHS) and rubber seed oil (RSO) contributes to the efficient utilization of agricultural waste. The thermodynamics and kinetics of four pseudo components from mixture (RSO: IHS=1: 1) are investigated using Asym2sig deconvolution. The results show that the Eα of pseudo hemicellulose, pseudo cellulose, pseudo triglyceride and pseudo lignin are 76.019, 193.587, 231.764 and 408.552 kJ/mol. The average differences in Eα and ΔH for the four pseudo-fractions also are 4.439, 4.929, 5.576 and 6.018 kJ/mol. Lower energy barrier favors the reaction. The frequency factor values for four pseudo-components pyrolysis are 1.07 × 10⁸ s⁻¹ for pseudo hemicellulose, 1.78 × 10¹⁹ s⁻¹ for pseudo cellulose, 6.04 × 10¹⁸ s⁻¹ for pseudo triglyceride, and 6.96 × 10³¹ s⁻¹ for pseudo lignin. The four pseudo-components have different pyrolysis reaction mechanisms. The synergistic effect calculations show a significant interaction between RSO and IHS. According to thermodynamic analysis, the pyrolysis of the four pseudo components requires the provision of external energy. FT-IR results indicate that RSO can significantly increase the release of C₂H₂, C₂H₄, C₂H₆ and CH₄ during the co-pyrolysis of RSO and IHS. The co-pyrolysis of IHS and RSO can increase the content of alkene, alkane and MAHs, which improve the quality of bio-oil significantly. Besides, it can reduce the content of PAHs, which reduces the viscosity of the bio-oil. The results can provide new insights into the synergistic and efficient disposal of triglycerides and lignocellulosic biomass.