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 furnace at different residence time of gases and temperatures and with a fuel-rich atmosphere and with an excess of oxygen. The yields of CO, CO2, six light hydrocarbons (methane, ethylene, etc.) and 31 semivolatile + volatile compounds (benzene, toluene, naphthalene, dibezofuran, etc,) were determined with stoichiometric: factors of the oxygen between 0.6 and 0.9, nominal temperatures of the reactor between 750-1050 degrees C and residence times of the volatiles evolved and formed between 2 and 6 s. The collection of the volatiles evolved was carried out with a Tedlar bag and by XAD-4 resin, comparing the data obtained in both cases. The maximum emission factors or yields of volatiles + semivolatiles were obtained at 850-950 degrees C, with values above 0.5% for benzene, naphthalene, acenaphthylene, phenantrene and fluoranthene. The thermal behaviour of different compounds was analysed. Naphthalene, benzene and toluene were also detected in the excess oxygen runs. (C) 2000 Elsevier Science B.V. All rights reserved.