Migration and transformation of sulfur and zinc during high-temperature flue gas pyrolysis of waste tires

Abstract

Waste tires (WT) are known as “black pollution”, and disposal of WT is an issue of concern. In addition, some coal-fired power plants have difficulty operating at full capacity. The use of high-temperature flue gas from coal-fired boiler for solid waste disposal was proposed as a solution. In this study, the weight loss properties of WT were investigated using TG-MS test. WT pyrolysis under simulated coal-fired flue gas was carried out, and the transformation characteristics of S and Zn during WT pyrolysis were performed. It indicated that the weight loss of WT was broken down into three main stages, which corresponded to the evaporation of water, the breakdown of the primary components, and secondary reactions. The principal sulfur-containing gas emitted throughout the weightless process was H2S. During WT pyrolysis in simulated flue gas, the temperature had a major impact on S and Zn enrichment in the solid product. At 750 °C, both exhibited high enrichment in the solid product. The addition of MgO promoted the enrichment of Zn. The addition of Fe2O3 resulted in the highest sulfur fixation in the solid product. Additionally, when flue gas pyrolysis was performed, all the sulfur in the solid product was sulfate. The research results of this paper can provide theoretical references for related pollutant control technologies.