Effect of inorganic substances and ageing on air pollutant concentrations from polyurethane foam combustion

Polyurethane (PU) foams are widely used in various applications, yet their combustion presents significant environmental and safety concerns due to toxic emissions. This study examines how inorganic additives (CaCO₃ and CaCl₂) and thermal ageing influence the release of gaseous pollutants during PU combustion. Aged and non-aged foams were combusted between 650 and 900 °C, with detailed analysis of flue gas composition (NOₓ, SO₂, CO, and CO₂). The results showed that ageing increased SO₂ emissions by up to 45 % and CO₂ concentrations by 10–15 %, while CO levels decreased by 20–30 % compared to non-aged samples. The addition of 10 % CaCO₃ to aged samples reduced CO emissions by up to 40 %, while 5 % CaCl₂ decreased SO₂ by approximately 25 % at 800 °C. The impact of additives was temperature-dependent and influenced the radical reactions during combustion, thereby affecting oxidation pathways and pollutant formation. These findings provide a deeper understanding of the factors governing PU combustion emissions and offer valuable insights into mitigation strategies for pollutant reduction in industrial and waste management settings. • Ageing has a strong effect on the concentration of flue gas components during PU combustion. • The CaO enhances the PU oxidation reaction, thus increasing the NO x emission. • Volatile organic compounds significantly alter PU combustion reaction pathways.