Do FeCl and FeCl/CaO conditioners change pyrolysis and incineration performances, emissions, and elemental fates of textile dyeing sludge?

The pyrolysis and incineration performances of sulfur-rich textile dyeing sludge (TDSS) were determined in response to the additions of FeCl or FeCl + CaO. The emissions of eight air pollutants from the incineration and pyrolysis were systematically identified. The 3-to-8% FeCl additions increased the comprehensive combustibility index by 2.14 and 1.62 times, respectively, as opposed to the 5-to-10% FeCl + 8-to-15% CaO additions. The CaO addition inhibited the TDSS incineration, while the FeCl addition increased HCl emission. NO, SO, and HS emissions decreased initially and increased between 600 and 950 °C. SO and NO emissions rose with FeCl but FeCl + CaO. FeCl catalyzed NO, while CaO retained SO. The main pyrolysis gas/liquid products were alkane, alkenes, nitrile, heterocyclic compounds, benzene, and its derivatives. Benzene and its derivatives accounted for 55.33% of the control group and 42.25-57.23% of the treatment groups. The FeCl and FeCl + CaO additions did not significantly influence the pyrolysis products. The measured versus thermodynamically simulated SO and HCl emissions were consistent. Neural network-based simultaneous optimizations of the non-linear dynamics of eight kinds of gases pointed to 50% and 14.4% reductions in the emissions and the pyrolytic temperature, respectively, with the 3% FeCl, relative to the control.