Treating Sulfur Dioxide Of Flue Gas By Polyamine Compounds In Aqueous Solution

Flue gas desulfurization (FGD) by using regenerative amine solution have some merits such as absorbing agent reusaging,not giving off waste material in system,economizing reclaimed sulfur dioxide, so it has widely practical perspective. Determining the shape of amine in aqueous solution is recently difficult problem. Three kinds of polyamine compounds are chosen to be the absorbing agent. On the base of studing on the property of polyamine compounds, the mechanism of polyamine compounds absorption of sulfur dioxide from polyamine compounds is investigated and the factors influencing absorption and desorption of sulfur dioxide are discussed by experiments.From the study of property of polyamine compounds, the protonated amines play the dominant role in the buffer action during the process of absorption and desorption sulfur dioxide. The experiment results are showed that the buffer capacity of polyamine compounds in aqueous solution is the strongest when pH=6～8. the optimal pH value of polyamine compounds in aqueous solution should be about 7 by jointly considering the process of absorption and desorption; the concentration of polyamine compounds in aqueous solution is 5/200 (ratio by volume of amine and water); the temperature is 20～50℃. Adding surfactants into the polyamine compounds in aqueous solution can lower the viscosity and surface tension of solution, and accelerate the desorption efficiency of sulfur dioxide. Dodecyl sodium sulfate is the best surfactants in this study.Simultaneously, the influence of absorption and desorption of sulfur dioxide by using two kinds of amines and water multivariate system is studied. Results show that the Diethylenetriamine/Triethylenetetramine solution (ratio by volume is 4/1) is the best mixture of absorbing medium if the total amine concentration is definite value.