Co-combustion behaviour of municipal waste and food waste using TG-FTIR and Py-GC/MS: Thermo-kinetic behaviour and gaseous pollutants emission

In China, co-combustion of municipal waste (MW) and food waste (FW) emerged as an attractive option for addressing fuel demand, optimizing blending ratio, and better waste management efficiency. This study investigates the co-combustion of industrially pre-treated MW, FW, and their blend samples, with a concentration on kinetics, thermal degradation, pollutant emissions, volatile products, and waste-to-energy potential using TG-FTIR-Py-GC/MS analysis from 40-1000 °C at 20 °C/min. The co-combustion of MW and FW involved four primary stages: drying (<252 °C), volatile emission (252–400 °C), combustion (400–550 °C), and char oxidation (550–1000 °C). The combustion indices linearly increased with increased FW blend. MW significantly interacted with FW in the active combustion temperature region (252–550 °C), with the evident synergistic effect and peak combustion indices observed at 50% FW. The lowest E_a exhibited by 35% FW (KAS:121.34 KJ/mol-Starink:119.87 KJ/mol) indicated a better choice for the energy recovery system. The FTIR analysis found that released gaseous pollutants were HCN, CO₂, CO, HCl, CH₄, C=C, NO, SO_2, etc. Further investigation found that the addition of 50% FW to MW exhibited adverse catalytic denitrification and dichlorination effects, with maximum reduction in hazardous pollutant emissions (CO, NO, SO₂, and HCl) at 300–600 °C. The Py-GC/MS analysis found that the presence of a high concentration of CaO in bottom ash catalysis during co-combustion reduced aromatic hydrocarbons and enhanced the value-added products aliphatic hydrocarbons and ketones. This study provides a fundamental reference for the co-combustion of MW, FW and thier blends in terms of potential feasibility, pollutant emission control, optimization, value added product for practical co-incineration application.