Pyrolysis and combustion characteristics of typical waste thermal insulation materials

Thermal insulation materials are important for building energy conservation, but their wastes have increased sharply. Furthermore, pyrolysis and combustion are increasingly utilized to dispose of solid wastes and convert them into value-added fuels. To better understand the pyrolysis and combustion characteristics of these materials, typical thermal insulation materials (expanded polystyrene (EPS) and extruded polystyrene (XPS)) were investigated by employing thermogravimetry and differential scanning calorimetry as well as cone calorimetry experiments. Pyrolysis behavior, kinetic parameters, pyrolysis index, thermodynamic parameters, endothermic properties and combustion parameters were estimated comprehensively. The results showed that EPS had better pyrolysis properties, while XPS had better combustion characteristics. Activation energies of EPS and XPS were 158.82 kJ/mol and 200.70 kJ/mol, respectively. Additionally, EPS had a higher pyrolysis stability index and comprehensive pyrolysis index, meaning a more intense reaction. Moreover, thermodynamic parameters indicated that the devolatilization products could be obtained easily from the two materials, and EPS and XPS could be converted into fuels. For the combustion, XPS had a smaller fire performance index and a larger fire growth index. These results can guide the reactor design and optimization for better converting polymer wastes into fuels and managing wastes.