Gas-pressurized torrefaction of biomass wastes: Roles of pressure and secondary reactions

Shan Tong; Yiming Sun; Xian Li; Zhenzhong Hu; Omar D Dacres; Nakorn Worasuwannarak; Guangqian Luo; Huan Liu; Hongyun Hu; Hong Yao

doi:10.1016/j.biortech.2020.123640

Gas-pressurized torrefaction of biomass wastes: Roles of pressure and secondary reactions

Bioresour Technol. 2020 Oct:313:123640. doi: 10.1016/j.biortech.2020.123640. Epub 2020 Jun 5.

Authors

Affiliations

¹ State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
² State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; Key Laboratory of Coal Clean Conversion and Chemical Process Autonomous Region, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830000, Xinjiang, China. Electronic address: xian_li@hust.edu.cn.
³ The Joint Graduate School of Energy and Environment, Center of Excellence on Energy Technology and Environment, King Mongkut's University of Technology Thonburi, 126 Pracha-Uthit Rd., Bangmod, Tungkru, Bangkok 10140, Thailand.

PMID: 32570077
DOI: 10.1016/j.biortech.2020.123640

Abstract

A gas-pressurized (GP) torrefaction method, proposed in our resent work, can significantly promote the upgrading and oxygen removal of biomass wastes, compared to the traditional torrefaction (AP). However, the mechanism of the GP torrefaction process is not clear. In present work, semi-closed (SC) torrefaction, GP torrefaction, and AP torrefaction were conducted to reveal the roles of pressure and secondary reactions during GP torrefaction quantitatively. The results showed that the pressure significantly promoted the upgrading of biomass during GP torrefaction at 200 °C. The contribution of pressure on the oxygen removal of GP torrefaction at 200 °C was 63.87%. At relatively high temperature of around 250 °C, the promotions were caused by the synergistic effect of pressure and secondary reactions. The contribution of secondary reactions on the oxygen removal was 53.99%. Thus, the process of the GP torrefaction of biomass wastes was preliminarily understood.

Keywords: Biomass; Gas-pressurized; Pressure; Secondary reactions; Torrefaction.

MeSH terms

Biomass
Hot Temperature*
Temperature