Co-pyrolysis of sewage sludge and waste tobacco stem: Gas products analysis, pyrolysis kinetics, artificial neural network modeling, and synergistic effects

This research comprehensively investigates the co-pyrolysis of sewage sludge (SS) and waste tobacco stem (WTS). Various SS and WTS ratios (1:0, 0.75:0.25, 0.50:0.50, 0.25:0.75, and 0:1) were tested over a range of heating rates (30 degrees C to 800 degrees C). Apparent activation energies were calculated using model-free methods, and the co-pyrolysis mechanism was described with the master plot method. Results suggest that SS and WTS co pyrolysis follows power-law models (P3, P4). Among blends, S75W25 exhibited optimal synergy, with the lowest activation energy required for the pyrolysis reactions and inhibits CO2 emissions. S75W25 ' s pyrolysis gas primarily contained acids (e.g., ethylxanthogenacetic acid, acetic acid), hydrocarbons (e.g., supraene, cyclopropyl carbinol), and other compounds (e.g., CO2, pyrazine, pyridine, indole). ANN was utilized to forecast the temperature-mass loss relationships in co-pyrolysis, with the optimal model being ANN21, yielding a highcorrelation coefficient (R2 = 0.99999). This study offers guidance for the efficient utilization of waste SS and WTS.