Flue gas torrefaction of municipal solid waste: Fuel properties, combustion characterizations, and nitrogen /sulfur emissions

• Published in: Bioresource technology 2022-05, Vol.351, p.126967-126967, Article 126967
• Main Authors: Zhu, Xiaochao, Li, Songjiang, Zhang, Yonggang, Li, Jian, Zhang, Ziqiang, Sun, Yunan, Zhou, Shengquan, Li, Ning, Yan, Beibei, Chen, Guanyi
• Format: Article
• Language: English
• Subjects: Chemical Phenomena; Combustion; Emission reduction; Flue gas torrefaction; Hot Temperature; Incineration - methods; Municipal solid waste; Nitrogen; Solid Waste - analysis; Sulfur; TG-MS
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.126967

[Display omitted] •The optimal flue gas torrefaction (FGT) parameters were at 300 ℃ and 30 min.•With FGT, higher heating value and energy density increased; H/C and O/C reduced.•FGT inhibited the NOx and SO2 release by 25.7% and 52.4%.•N/S contaminate reduced by volatile release, char and reducing gases increasement. Flue gas torrefaction (FGT) was proposed as the pretreatment of the municipal solid waste (MSW) combustion process to improve the fuel properties of MSW and achieve better combustion performance. The optimal FGT parameters were obtained at 300 ℃ and 30 min, with the energy-mass co-benefit index (EMCI) reaching the maximum of 23.38. FGT could significantly increase the heating value and energy density of MSW while reducing the H/C and O/C ratio. Then, the pyrolysis and combustion experiments were performed by tube furnace and TG-MS. The results proved the chemical compositions of MSW were altered, and the heat transfer was enhanced. With FGT, NOx and SO2 emissions could be reduced by 25.7 % and 52.4 %, respectively. This study provides an in-depth understanding of the mechanism of FGT and paves the way for the clean treatment and energy utilization of MSW.