Study On Flue Gas Desulphurization Of Medium And Small Sized Coal-Fired Boiler By Liquid Phase Catalytic Oxidation

Based on reviewing a lot of major-related literatures and summarizing our previous work, a liquid phase catalytic oxidation flue gas desulfurization (FGD) purification line, which used Mn²⁺ as a catalyst, was employed to investigate medium and small sized coal-fired boiler in this paper. In order to optimize the process parameters, a model which simulated practical operations was established to study the state of Mn²⁺ FGD in the laboratory. The results show that when the concentration of SO₂ is less than 2000mg/m³, the flue gas flow is 90L/h, the volume of liquid absorption is 20mL, the temperature is 28℃, the pH is 5-6 and the Mn²⁺ concentration is 0.12mol/L, the desulfurization efficiency can reach 85%.In order to further verify the feasibility of Mn²⁺ catalyst for FGD in medium and small sized coal-fired boiler, the boiler room of Qinhuangdao Environmental Management Academy was taken as the test location. The existing water bath dust extractor was used to do the coal-fired boiler test. During the heating period and in condition of the normal operation of the boiler, the concentration of Mn²⁺ solution was modified to inspect the desulfurization efficiency. It is concluded that when the concentration of Mn²⁺ reaches 0.1mol/L, the 70% desulfurization efficiency can be achieved and the national emission standards can be met, and FGD which uses Mn²⁺ as catalyst is effective for the medium and small sized coal-fired boiler.Comparing the results of the field experiments and the laboratory experiments, and combining the boiler characteristics of Qinhuangdao Environmental Management Academy, the boiler produced by Benxi Boiler Corp. was taken as an example, the reconstructive plan was proposed for the dust desulfurization process and the investment income was analyzed. The results show that the reconstruction for the existing desulfurization process isvaluable to alleviate the pollution of medium and small sized coal-fired boiler.In all, a liquid phase catalytic oxidation FGD purification line which uses Mn²⁺ as catalyst has an important guiding significance to solve the problems of existing medium and small sized coal-fired boilers.