Pulverization of municipal solid waste and utilization of pulverized product as alternative fuel for blast furnace injection

Abstract

In order to utilize municipal solid waste (MSW) in blast furnace ironmaking to realize synergistic reduction of pollution and carbon emissions, a novel method for pulverization of MSW by low temperature heat treatment and crushing, and evaluation of the properties of pulverized product for blast furnace injection were performed. In the present research work, residual waste obtained from MSW classification under the conditions of most Chinese cities was used as the representative raw material. The crushing performance of MSW can be improved by heat treatment. Considering the weight loss ratio, pulverization effect and density of heated MSW at different temperatures and durations, the optimal heat treatment parameters can be set as 300 °C and 20 min. The volatile content, fixed carbon content, ash content, S content, lower heating value of the pulverized product were 61.56 wt%, 19.02 wt%, 19.42 wt%, 0.39 wt% and 25.47 kJ/g, respectively. The pulverized product had worse fluidity and similar jet flow compared to industrial injection coal. Its decomposition heat for injection was 1732 kJ/kg. The initial combustion temperature and burnout temperature of the mixed fuel gradually decreased with the increasing of added pulverized product due to its much better combustion property. About 0.163 kg CO₂ can be reduced if 1 kg of raw MSW was injected into blast furnace. The experimental results demonstrates that the obtained pulverized MSW could be used for blast furnace ironmaking to some extent as an environmentally friendly, low-carbon, and economically substitute of fossil fuel.