Thermal pyrolysis characteristics and kinetics of hemicellulose isolated from Camellia Oleifera Shell

• Published in: Bioresource technology Vol. 282; pp. 228 - 235
• Main Authors: Lei, Zhihui, Wang, Shengdan, Fu, Haocheng, Gao, Wenhua, Wang, Bin, Zeng, Jinsong, Xu, Jun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2019
• Subjects: Camellia Oleifera Shell; Hemicelluloses; Kinetic; Pyrolysis; Thermogravimetric analysis; Pyrolysis; Hemicelluloses; Camellia Oleifera Shell; Kinetic; Thermogravimetric analysis
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.02.131

[Display omitted] •Hemicelluloses were successfully isolated from COS by alkali/ethanol treatment.•The thermal pyrolysis parameters were determined by Coats-Redfern, FWO and KAS models.•The isolation technology of COS hemicelluloses affected its thermal stability.•The thermal stability of COS hemicelluloses were reflected by thermodynamic parameters. Camellia Oleifera Shell (COS) is a kind of renewable lignocellulose resource and contains abundant hemicelluloses. In this work, the hemicelluloses in COS were extracted by alkali treatment and precipitated by ethanol with different concentration. Thermal pyrolysis kinetics of COS hemicelluloses were investigated using a thermogravimetric analyzer at the heating rates of 5, 10, and 20 °C/min based on Coats-Redfern, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) model. The results showed that the best fitting thermal pyrolysis mechanism of COS hemicelluloses was one-dimensional diffusion reaction analyzed by Coats-Redfern model. The activation energies of COS hemicelluloses ranged from 175.07 to 247.87 kJ·mol−1 and from 174.74 to 252.50 kJ·mol−1 calculated by FWO and KAS, respectively. The thermal stabilities of COS hemicelluloses were enhanced with the precipitated ethanol concentration increasing, and reflected by thermodynamic parameters ΔH, ΔG and ΔS. This study may provide basic theoretical supports for the thermochemical conversion of COS hemicelluloses.