Co-combustion of textile dyeing sludge with cattle manure: Assessment of thermal behavior, gaseous products, and ash characteristics

Not only can the incineration provide an effective waste stream reduction, but also it enhances the energy recovery. However, the combustion performance of textile dyeing sludge is poor due to its low combustible content and low calorific value. This study proposes to compensate for the defects by its co-combustion with cattle manure. The co-combustion exerted an inhibitive effect between 350 and 500 °C and a positive effect between 600 and 1100 °C on the thermal degradation. The strongest enhancement occurred with the blend ratio of 1:1. The co-combustion reduced the maximum SO2 emission and produced fewer gas species including CO2, CO, H2O, ketones, aldehydes, and low molecular weight chain-alkanes. The experimental and simulation results about mineral transformations showed that the blend ash consisted of SiO2, Fe2O3, CaMgSi2O6, NaAlSiO4, NaAlSi3O8, and Na2SO4. The blend ash had the lowest fusion temperature due to the formation of a low temperature eutectic. The findings provide insights into controls over gas emissions, energy recovery, and ash reutilization, essential to the development of cleaner and sustainable co-combustion systems. •Textile dyeing sludge and cattle manure were evaluated as a co-fuel.•Mineral transformations were analyzed combining experiments and simulations.•Decomposition was inhibited between 350 and 500 °C but promoted at above 600 °C.•Co-combustion mainly emitted CO2, CO, H2O, C–H, ketones, and aldehydes.•Co-combustion had a lower ash fusion temperature.