Toxic byproducts from the combustion of varnish wastes based on polyurethane in a laboratory furnace

Varnish wastes based on polyurethane were burnt in a laboratory scale furna ce at different residence time of gases and temperatures and with a fuel-ri ch atmosphere and with an excess of oxygen. The yields of CO, CO2, six ligh t hydrocarbons (methane, ethylene, etc.) and 31 semivolatile + volatile com pounds (benzene, toluene, naphthalene, dibezofuran, etc,) were determined w ith stoichiometric: factors of the oxygen between 0.6 and 0.9, nominal temp eratures of the reactor between 750-1050 degrees C and residence times of t he volatiles evolved and formed between 2 and 6 s. The collection of the vo latiles evolved was carried out with a Tedlar bag and by XAD-4 resin, compa ring the data obtained in both cases. The maximum emission factors or yield s of volatiles + semivolatiles were obtained at 850-950 degrees C, with val ues above 0.5% for benzene, naphthalene, acenaphthylene, phenantrene and fl uoranthene. The thermal behaviour of different compounds was analysed. Naph thalene, benzene and toluene were also detected in the excess oxygen runs. (C) 2000 Elsevier Science B.V. All rights reserved.