Effects of sorbents on the heavy metals control during tire rubber and polyethylene combustion in CO2/O2 and N2/O2 atmospheres

This paper investigated the capture behavior for three heavy metals (Cu, Ni and Zn) during the waste tire rubber (TR) and high density polyethylene (HDPE) combustion in N2/O2 and CO2/O2 atmospheres in a lab-scale tubular furnace. Both the replacement of N2 by CO2 and addition of limestone decreased the evaporation of Ni, Cu and Zn during TR and HDPE combustion. Replacement of N2 by CO2 increased the capture efficiency of limestone for Zn, Cu and Ni from TR combustion (except for Ni at 700 °C), but decreased for capturing Zn, Cu and Ni from HDPE combustion. The waste composition highly influenced the capture efficiency of limestone for Zn, Cu and Ni, but the amount of sorbent only significantly affected the capture efficiency of limestone for Ni. The increment of the furnace temperature increased the capture efficiency of limestone for Zn but decreased for Ni. The sorption efficiency of limestone was worse than CaO. This work contributes to the control of heavy metals during municipal solid waste (MSW) incineration and management of MSW oxy-fuel combustion.