Study on the Effect of Torrefaction on Pyrolysis Kinetics and Thermal Behavior of Cornstalk Based On a Combined Approach of Chemical and Structural Analyses

Xincheng Lu; Ruting Xu; Kang Sun; Jianchun Jiang; Yunjuan Sun; Yanping Zhang

doi:10.1021/acsomega.2c00047

Study on the Effect of Torrefaction on Pyrolysis Kinetics and Thermal Behavior of Cornstalk Based On a Combined Approach of Chemical and Structural Analyses

ACS Omega. 2022 Apr 18;7(16):13789-13800. doi: 10.1021/acsomega.2c00047. eCollection 2022 Apr 26.

Authors

Xincheng Lu^{1

2}, Ruting Xu¹, Kang Sun¹, Jianchun Jiang¹, Yunjuan Sun¹, Yanping Zhang¹

Affiliations

¹ CAF; Key Laboratory of Biomass Energy and Material, Jiangsu Province; Key and Open Laboratory of Forest Chemical Engineering, SFA; National Engineering Laboratory for Biomass Chemical Utilization, Institute of Chemical Industry of Forest Products, Nanjing, Jiangsu 210042, PR China.
² Co-innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing, Jiangsu 210042, PR China.

Abstract

In this study, the effects of torrefaction pretreatment on physicochemical characteristics and pyrolysis behavior of cornstalk were investigated based on the changes in its chemical and structural characteristics. The results indicated that torrefaction treatment improved the fuel properties with elevated torrefaction temperature, including the lower volatile content, higher carbon content, and higher heating value. In addition, serious torrefaction promoted complete degradation of hemicellulose, while the lignin was increased obviously. The crystallinity degree of cornstalk increased first and then reduced with the torrefaction temperature. Slight torrefaction enhanced the devolatilization and thermochemical reactivity of cornstalk, but serious torrefaction discouraged the volatile release. Kinetic parameter analysis indicated that the Ozawa-Flynn-Wall model was more accurate in calculating the activation energy, and the average activation energy gradually increased from 196.06 to 199.21, 203.17, and 217.58 kJ/mol. Furthermore, the thermodynamic parameters also showed an increasing trend with elevated torrefaction temperature. These results provide important basic data support for the thermochemical conversion of cornstalk to energy and chemicals.