Insights into the interactions between cellulose and hemicellulose during pyrolysis for optimizing the properties of biochar as a potential energy vector
Xiaoran Li, Kehui Cen, Jin‐Jin Li, Dongxia Jia, Jiangyong Gao, Liqiang Zhang, Dengyu Chen
Abstract
Cellulose and hemicellulose, the main components of biomass, undergo noticeable interactions during biomass pyrolysis . In this study, biochar was produced by the co-pyrolysis of cellulose and hemicellulose. Three co-pyrolysis parameters, namely, pyrolysis temperature (400–800 °C), residence time (5–30 min), and percentage of cellulose (0–100 %), were investigated to optimize the properties of biochar, including the application of response surface methodology in the experimental study. The analysis revealed that co-pyrolysis interactions could improve the biochar yield by up to 41.37 % (567.74 °C, 19.52 min, 50 % cellulose percentage). The co-pyrolysis interactions specifically enhanced the fixed carbon content, elemental carbon content, and higher heating value of the biochar, with the most significant enhancements being 0.87 %, 3.60 %, and 3.85 %, respectively, while simultaneously decreasing the volatile content, [H]/[C] ratio, and [O]/[C] ratio of the biochar, with the most significant reductions of −9.30 %, −10.81 %, and −26.71 %. Based on the observed decrease in the intensity ratio of the D-band and G-band of biochar in the Raman spectra, greater co-pyrolysis interactions increased the graphitization degree of the biochar. The analysis of X-ray photoelectron spectroscopy (XPS) investigations revealed that the interactions enhanced the contents of the C-C, C-O/C-O-C, aromatic, and OH functionalities while reducing the number of COO-, COOH, and C O functional groups. The results of this work indicate that the co-pyrolysis interaction between cellulose and hemicellulose contributes to optimizing the properties of biochar as a potential energy vector.