A component synergy of flue gas torrefaction of municipal solid waste

Abstract

Flue gas torrefaction (FGT) is a promising pretreatment to improve the fuel properties of municipal solid waste (MSW). A synergistic effect between paper, wood and PVC was studied in flue gas and nitrogen torrefaction atmospheres. FGT presented superior potential in improving fuel properties compared to nitrogen torrefaction (NT). Notably, the synergistic effect between different ingredients in FGT could reduce mass and energy losses effectively, especially the combination of PVC with other materials. Besides, the FGT samples exhibited better thermal stability than NT samples during pyrolysis and combustion. Simultaneously, FGT led to the released flammable gases (H2 and CO) increase, while H2O decrease. Satisfyingly, less gaseous pollutants were released during the FGT samples combustion, attributed to the reduction of light volatiles and the enrichment of char and heavy volatiles. Moreover, the positive synergistic effects of FGT or NT blended samples were found in the pyrolysis (in phase B: ∆WNT-DTG = 4.79–5.20 and ∆WFGT-DTG = 0.78–1.18) and combustion (in phase B: ∆WNT-DTG = 6.03–16.07 and ∆WFGT-DTG = 1.56–13.4). This study can provide a theoretical reference for the efficient and clean treatment of MSW.