An investigation on pyrolysis of textile wastes: Kinetics, thermodynamics, in-situ monitoring of evolved gasses and analysis of the char residue

Abstract

Recycling the ever-increasing industrial waste has become a pressing concern globally and pyrolysis is regarded as one of the up-and-coming techniques to recover the energy and chemical content of organic wastes. The pyrolysis of a representative industrial waste as textile waste was investigated within the scope of this study. In this way, efficient thermochemical conversion processes may be designed and optimized by creating value-added products. Different heating rates were applied to determine pyrolysis behavior using a thermogravimetric analyzer (TGA) coupled with a mass spectrometer (MS) and a Fourier transform infrared spectrometer (FT-IR). According to the obtained thermograms, the active pyrolysis region was selected for studying the kinetics, various iso-conversional methods (Friedmann, Kissinger-Akahira-Sunose; Flynn-Wall-Ozawa and Starink) were applied to the non-isothermal TG data, and the results were compared among themselves. The mean activation energy was 186.7, 185.8, 185.1, and 185.5 kJ/mol for the Friedmann, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, and Starink models, respectively. The activation energy variation was found in good agreement among different kinetic models. The activation energy changes that were found provided a representation of the process kinetics which were described by multiple reaction schemes. All four kinetic methods were found to be appli-cable to forecasting the non-isothermal pyrolysis of textile wastes, although the existence of small variations in the activation energy values. Furthermore, thermodynamic parameters as enthalpy, Gibbs free energy, and en-tropy changes were estimated.The gasses that evolved during pyrolysis were identified by simultaneous moni-toring of MS and FT-IR spectra and the temperature-dependent alteration of main volatile products were obtained. Moreover, the char residue was analyzed via ex-situ SEM-EDX and FT-IR.