Characteristics of chlorine and carbon flow in two municipal waste incinerators in Taiwan

Characteristics of chlorine and carbon flow at two municipal solid waste incinerators (MWIs) equipped with different air pollution control devices in Taiwan are investigated based on sampling/analysis and system operating data. The distribution of chlorine and carbon at various locations were evaluated based on the mass concentrations and emission rates. The removal efficiencies of HCI are 88.3 and 94.1% at MWI-A and MWI-B, respectively. Approximately 60% of the chlorinated compounds (expressed as chlorine) from municipal solid waste (MSW) at both MWIs exists in particulate form after incineration and is captured by the baghouse or electrostatic precipitator. The rest, 30-40% of the chlorine, is removed with bottom ash and wet scrubbing liquid or cyclone ash discharge at both MWIs. The results indicate that approximately 98% of the carbonaceous compounds contained in MSW is converted to CO₂ and emitted from the stack at both MWIs due to good incineration efficiency. CO₂ emission factors are 845 and 816 kg/ton waste for MWI-A and MWI-B, respectively. The mass percentages of chlorine and carbon in the municipal solid waste are then back-computed. The chlorine contents are 0.53 and 0.72% whereas the carbon contents of MSW are back-calculated as 23.5 and 22.7% for MWI-A and MWI-B, respectively.