Co-pyrolytic valorization and synergistic interactions of waste tire and corn plant stalk: A detailed study on kinetics, thermodynamics attributes, drivers, and mechanistic pathways of pollutants reduction

Waste tire (WT) pyrolysis is a well-known technique for the production of fuel, but the formation of pollutants such as PAHs, S-compounds and N-compounds is inevitable due to the existence of sulfur, nitrogen and several additives. The co-pyrolysis of waste tire with biomass can be a viable solution to inhibit the pollutants to mitigate environmental issues. Therefore, co-pyrolysis of waste tire and corn plant stalk (CPS) is performed in TG-MS and Py-GCMS to investigate the synergistic effect. The addition of CPS improved pyrolysis efficiency of WT which resulted in earlier decomposition temperature and reduction in residual from 35.44 wt% to 27.75 wt%. Kinetics and thermodynamic analysis revealed that the average activation energy of co-pyrolysis blends decreased from 83.9 kJ/mol to 46.3 kJ/mol and the addition of CPS avoid the activation complex. The peaks intensities of SO₂ and H₂S were highest compared to COS, CS₂ and CH₃SH in WT100 but NH₃ and HNCO in CPS100 showed maximum peaks than HCN, NO. The peaks of 9 series of gaseous PAHs in WT100 were higher than CPS100. The blend ratios WT/CPS 2:2 and WT/CPS 1:3 reduced the emission of gaseous sulfur, nitrogen and PAHs compounds. The effect of final pyrolysis temperature and blend ratios in Py-GCMS analysis unveiled that co-pyrolysis maxing ratio WT/CPS 2:2 at 500 ℃ effectively minimized the phenolic, aldehydes, ketones, and acids which enhanced the fuel quality as well as lowered the benzene derivatives/ single ring aromatic hydrocarbons (SRAH) which are regarded as PAHs precursors. Furthermore, the difference between experimental and calculated yield confirms that the synergistic effect completely inhibited PAHs and decreased the N-compounds and S-compounds as well as increased the alkene and olefins. So, the results indicated that co-pyrolysis of WT with biomass can significantly restrain the pollutants and enhance the pyrolytic oil quality which can be used as an alternative environmental friendly fuel.