Heat accumulations and fire accidents of waste piles

In order to prevent fires from waste storages and piles, heat generation and accumulation mechanism of waste piles were investigated by calorimetric and chemiluminescence (CL) studies. As measurement samples, we used refuse-derived fuel (RDF), car shredder dust (SD), and model materials such as papers and plastics. A primary heat generation and a heat accumulation were evaluated by using some calorimeters such as DSC (Mettler Toledo, Schweiz), ARC (Columbia Scientific Ind., USA) and C80 (Setaram, France). Self-ignition temperature was also evaluated by using HP-TG/DTA (Rigaku, Japan). However, these values of wastes vary with respect to each sample due to the heterogeneity of the wastes. For instance, the self-ignition temperature of SD was 154–186 °C and that of RDF was 174–224 °C. In this study, we chose the lowest value from the safety point of view. The results of ARC measurement indicated that the heat accumulation by self-heating started from 83 °C for RDF, and from 96 °C for SD, and the heat accumulation under adiabatic condition gave self-ignition eventually. We also studied the oxidation of them in the low temperature region (between room temperature and 130 °C) using CL analyzer (Tohoku Electronic Ind., Japan). The experimental data showed that RDF containing oxidized polymer and some organic peroxides initiated autoxidation reaction in the low temperature region.