Co-pyrolytic mechanisms and products of textile dyeing sludge and durian shell in changing operational conditions

Textile dyeing sludge (TDS) is a highly toxic solid waste whose co-pyrolysis can jointly achieve waste reduction and recovery of value-added products. This study aimed to fill the knowledge gaps about the co-pyrolysis mechanisms and products (gases and solids) and their dynamics in response to the atmosphere type, blend ratio, heating rate, temperature, and their interactions. The high temperature pyrolysis (>720 degrees C) in the CO2 atmosphere appeared as the best option for the waste reduction. The (co-)pyrolysis in the CO2 atmosphere enhanced S-containing air pollutants, CO, and CH4 but reduced NOx. The interaction effect between TDS and durian shell (DS) residues promoted the productions of furan and acid compounds and inhibited the productions of aromatic, phenolic, and N-containing compounds. The atmosphere type affected the type and strength of the reactions involved in the production of biochars. Our findings provide practical and new insights into the optimization of energy generation, product recovery, and emission control during the (co-)pyrolysis.

Automated summary

This study filled the knowledge gaps about the co-pyrolysis mechanisms and products of textile dyeing sludge (TDS), with findings suggesting that high temperature pyrolysis in CO2 atmosphere is the best option for waste reduction. The interaction between TDS and durian shell (DS) residues influenced the composition of products, promoting the production of specific compounds.