Combustion characteristics of typical model components in solid waste on a macro-TGA

Abstract

The combustion characteristics of nine typical model components (PE, PET, PVC, PS, cellulose, hemicellulose, lignin, pectin and starch) in municipal solid waste were experimentally investigated on a custom-designed macro-thermal gravimetric analyzer (macro-TGA) at three heating rates of 10, 20 and 30 °C min−1. The combustion characteristics of biomass components (cellulose, hemicellulose, lignin, pectin and starch) were a little more complex than those of plastics (PET, PET, PVC and PS), which indicated that combustion was related to not only proximate analyses results, but also the chemical structure and specific chemical reactions. With the increase in the heating rates, the decomposition of all samples except for lignin was delayed. The main peak temperature of 20 °C min−1 was 30–55 °C higher than that of 10 °C min−1 and 20–40 °C and lower than that of 30 °C min−1 on macro-TGA. Some adjacent peaks in the differential thermogravimetric curves moved closer to each other or overlapped together. The residues of biomass components rose evidently with the increase in the heating rate from 10 to 20 °C min−1, while the plastic components almost burned out during combustion. The kinetics analysis based on Flynn–Wall–Ozawa method was used to calculate the activation energies of the samples. The activation energies of biomass components on the macro-TGA were mostly below 50 kJ mol−1, whereas those of plastic components were mainly between 40 and 140 kJ mol−1.