Comparative study on synergistic effects in co-pyrolysis of tobacco stalk with polymer wastes: Thermal behavior, gas formation, and kinetics

Co-pyrolysis of tobacco stalk (TS) with different types of polymer wastes such as scrap fire (ST), polypropylene (PP) and polyvinyl chloride (PVC) was investigated. Thermogravimetric analyzer coupled with Fourier transform infrared spectrometer was carried out to examine the thermochemical properties, kinetics, and gas generation. The results of the co-pyrolysis showed a synergistic effect compared to the pyrolysis of the individual components. When using TS/ST co-pyrolysis, the reduction in char residue was about 6% (dry wt. basis) and the increase in organic gases exceeded 20%. It indicates that the addition of ST can increase both carbon conversion efficiency and volatiles yield. HCl from PVC underwent a complex physicochemical reaction with TS, increasing coke yield by 11-12% and inhibiting the gas release. In the main pyrolysis temperature range of ST, the activation energy is reduced by 40-80% by blending with TS; for PP this value is reduced by about 22%.