Mixture Of Paper Research Articles

A study of the thermal degradation of six typical municipal waste components in CO2 and N2 atmospheres using TGA-FTIR

Thermal degradation of six typical municipal solid waste (MSW) components (tire rubber (TR), recycled polyvinyl chloride pellets (PVC), wood sawdust (WS), paper mixture (PM), kitchen waste (KW) and textile (TE)) in CO2 and N2 atmospheres is studied by using a thermogravimetric analyzer (TGA) combined with Fourier transform infrared (FTIR) spectrometer. Below 600°C, CO2 behaves as an inert atmosphere and samples display similar weight loss behavior in both atmospheres. In this temperature range, the gas species and variations of FTIR absorbance depend on the waste composition rather than atmosphere type. Most of gases display identical evolution trends in both N2 and CO2, and the experience for pyrolysis in N2 can also be used for pyrolysis in CO2, and simply replacement of N2 by CO2 can’t improve the pyrolysis performance. Above 600°C, atmosphere changes not only the location of the DTG peak but also its formation mechanism, and CO2 behaves as a reaction atmosphere. In the later thermal degradation, the growth rate of CO absorbance in CO2 is significantly faster than in N2, indicating waste pyrolysis in CO2 can increased the syngas production at higher temperatures.

Heavy metal enrichment characteristics in ash of municipal solid waste combustion in CO2/O2 atmosphere

This paper investigated the behavior of six heavy metals (Cd, Pb, Cu, Cr, Ni and Zn) in the bottom ashes of recycled polyvinyl chloride pellets (PVC), wood sawdust (WS) and paper mixture (PM), representing the common components of municipal solid waste (MSW), obtained during combustion in CO2/O2 atmosphere in a lab-scale electrically heated tube furnace. Replacement of N2 by CO2 did not obviously change the shape of relative enrichment factor (RE) curves and subsequent order of heavy metals, but increased enrichment of these heavy metals in bottom ashes of WS, PM and PVC. The increment of O2 concentration in CO2/O2 atmosphere further increased RE values. It was only when the temperature was higher than or equal to 700°C that the increment of the combustion temperature reduced the RE values of heavy metals. The effect of temperature on heavy metals evaporation was the most pronounced for the medium volatile metal Pb, and the least for the low volatiles Cr and Ni. The effect of temperature was more pronounced for PVC ash than for WS and PM ashes. This paper contributes to the control of heavy metals during MSW incineration and management of MSW oxy-fuel residues.