New technology of efficient pulverization of simulated municipal solid waste based on low temperature heat treatment and properties of pulverized product for blast furnace injection

Abstract

The recovery of energy from municipal solid waste(MSW) is of great importance for the sustainable development of human society. Transforming MSW into fuel is a very good technology, where pulverization pretreatment is a key point for the massive utilization of MSW as solid fuel. In this paper, the representative components of MSW, such as polyvinyl chloride (PVC), polyethylene (PE) and biomass, were used as raw materials. PVC, PE, biomass and their mixtures were heated at different temperatures. Then the heat treatment products were crushed and the pulverization properties of the heat treatment products were analyzed. Finally, the de-chlorination ratio, lower heating value, powdery properties and combustion properties of the pulverized MSW were investigated. As the heat treatment temperature increased from 240 °C to 390 °C, the crushing performance of PVC and biomass were gradually improved, while PE was difficult to be crushed. PVC and biomass could improve the crushing performance of PE after mixing heat treatment with PE separately. PVC, PE and biomass were mixed to simulate the composition of MSW, and the ternary mixture had good crushing performance after heated at 330 °C for 30 min. The maximum de-chlorination ratio of 86.10 % was achieved, and the relative chlorine content in the product was 2.61 %. The volatile content of the pulverized MSW was 75.81 %, the fixed carbon content was 16.34 %, and the ash content was 7.85 %. The lower heating value of the pulverized MSW was 28829 kJ/kg. Compared with traditional injection coal, the pulverized MSW had good fluidity and strong jet flow. It also showed better combustion performance. The results show that the pulverized MSW obtained in this study could be used in blast furnace injection for the replacement of coal to some extent.