Volatilization characteristics of solid recovered fuels (SRFs)

The volatilization characteristics of three MSW-derived materials (FO, RT and FL) produced by local waste-management companies were investigated as potential solid recovered fuels (SRFs). FL was prepared from sorted domestic waste and consisted of non-recyclable plastics, refuse paper and biomass. RT and FO were obtained through active hygienization of unsorted MSW and refuse materials from selective waste-collection streams. RT was rich in plastics and had low biomass, whereas FO was mainly biomass and refuse paper. The rate of energy release during volatilization depended on the content of biomass and plastic, especially at a low conversion. Major contaminants had different rates of volatilization. Nitrogen and sulfur tended to accumulate in the charred solid, and were released as SO2 and nitrous oxides during both the volatilization–combustion stage and the char burning stage. Chlorine release was faster for the fuels rich in plastic waste. According to their ash melting characteristics and slagging indexes (Fs: 1188 °C for FO, 1192 °C for RT and 1234 °C for FL) the three fuels were equivalent to commercial SRFs. The three fuels showed potential as standardized SRF, although it would be desirable to reduce their chlorine content and, in the case of FO, to increase it’s heating value.