Study on Utilization Ratio of SO2 Sorbents in Semidry Flue Gas Desulfurization Technology

From the angle of chemical compositions of the desulfurization products, the utilization ratio of SO₂ sorbents in semidry flue gas desulfurzation (FGD) technology was discussed in this study. Five desulfuzation residue samples, which were got from the semidry FGD devices of five different power plants, were analyzed about the chemical compostions. It was found that CaCO₃ took up a big proportion among the desulfurzation products. Through calculation and deduction, the CaCO₃ should have been generated from the desulfurization process. This consequence does not accord with the routine researches in which the effect of CO₂ usually isn´t considered. Then experiments were carried out and it was proved that the competitive reactions with the sorbent Ca(OH)₂ between CO₂ and SO₂ do exist. Therefore, the problem that the sorbent utilization ratio is low in semidry FGD technology was put forward and given explanation. Measures must be taken to prevent the reaction between CO₂ and Ca(OH)₂ in order to improve the semidry FGD technology.