抄録
A large amount of PVC (polyvinyl chloride) insulation material used as main covering of electric cables is mostly disposed in landfills. To utilize PVC insulation wastes as fuel gas, fuel oil and refuse-derived fuel, it is important to study the influence of some additives such as lead stabilizer (PbSO4) on their pyrolysis behavior and to estimate the interaction of Cl, S compounds with Pb compounds. In the present study, the evolution behavior of these compounds involved in PVC waste during pyrolysis was investigated. In the experiment, a mixture of PVC and PbSO4 was used as a model sample of PVC insulation waste. Pyrolysis was done in a gas flow type tubular reactor in the temperature range of 673-1073K in N2 atmosphere and H2O (10%) atmosphere. The amount of HCl and SO2 emitted during the pyrolysis of the sample was measured by a Fourier Transform Infrared Spectroscopy (FTIR). It was found that the rate of HCl emission increased with an increase in temperature. At 1073K, about 85% of chlorine in sample was released as HCl. At this temperature, emission of HCl was improved further in the pyrolysis with H2O. On the other hand, the amount of SO2 emitted from the sample decreased with an increase in temperature. Under the present condition employed, SO2 was changed into H2S. Sulfur compounds remaining in the solid residue decreased, when H2O was present in the pyrolysis atmosphere. It was also found that the amount of lead contained in solid residue after PVC-PbSO4 pyrolysis was larger at 873K and 1073K than at 673K.
