2019 Volume 98 Issue 4 Pages 44-51
SO2 and HF emitted from coal-combustion is a serious problem of indoor air pollution in China. Powdery coal mixed with Ca(OH)2, which is called coal-briquette, was suggested to control SO2 and HF emissions from coal combustion, but it is thought that desulfurization and defluorination occur at the same time during the combustion of coal-briquette. The objective of this study is to clarify the interaction of desulfurization and defluorination reactions during the coal-briquette combustion. This research work focuses on the removal of SO2 and HF from coal combustion. Carbonaceous graphite, muscovite and FeS2 are used to make simulated briquettes, as carbonaceous graphite provides carbon, muscovite contains fluorine and FeS2 contains sulfur. Ca(OH)2 is used as an additive to the simulated coal-briquettes to remove SO2 and HF. As the result, it was found that HF generation is a first-order reaction and that existing sulfur in the simulated coal-briquettes has an influence on defluorination efficiency. The experimental result showed that the emitted SO2 concentration increased with an increase of fluoride content in the simulated coal-briquettes. Further, our data showed that if pyrolysis of fluoride (muscovite) proceeds in the simulated coal-briquettes combustion, desulfurization efficiency decreases.
