Synergetic effects during co-pyrolysis of waste textiles and Ca/Fe-rich industrial sewage sludge: Reaction kinetics and product distribution.

Co-pyrolysis is a promising technology for industrial organic waste to utilize their unique resource and energy properties for efficient conversion into valuable products. This study was the first time to characterize the co-pyrolysis of waste textiles with Ca-rich industrial sludge and Fe-rich industrial sludge on a laboratory-scale fixed bed. The properties, mechanisms, gas, oil and carbon production were investigated as a function of temperature and mixing type. Co-pyrolysis increased the total weight loss from 50.05 % to 69.81 % for Ca-rich industrial sludge mixed with 50 % waste textiles and from 49.13 % to 70.01 % for Fe-rich industrial sludge mixed with 50 % waste textiles. The activation energy of co-pyrolysis was approximately 50 % lower compared to the pyrolysis of waste textiles alone. The optimal reaction model for the different reaction stages for all samples was three diffusion (D3). Co-pyrolysis resulted in lower CO and CO2 emission temperatures of about 25-110 °C and produced more short-chain organic compounds (C < 10). Co-pyrolysis produced more aldehydes and ketones organics. Moreover, co-pyrolysis char exhibited an elevated level of fatty alkyl side chains and bridge branching, as well as higher degrees of aromatization and stability. This study offers valuable insights into the potential application of pyrolysis for the management of Ca/Fe-rich industrial sludge and waste textiles, thereby serving as a basis for future utilization endeavors.