Physicochemical Properties Of Ethanolamine Lactate During SO₂ Absrption And Absorption Of SO₂ In Simulated Flue Gas With Ionic Liquid

Sulfur dioxide (SO2) is a kind of atmospheric pollutants. It can not only cause environmental pollution and also threaten the health of people. SO2 is a kind of very important chemical materials at the same time. SO2 is mainly emitted from the burning of fossil fuels and the smelting of metals. Therefore, there is an extreme significance for our survival and development to capture and reuse of SO2 from these industrial process. Ionic liquid (IL) is a kind of new absorbents, which has excellent absorbing properties to capture of SO2. However, nowdays the study about absorbing SO2 by ionic liquid is just a fundamental research in test tubes, there is no experiment about this process in a large-scale desulfurization device. In this work, a large-scale desulfurization device was designed and made to investigate the absorption of SO2 in simulated flue gas with ionic liquid at different conditions, in order to provide fundamental data and theoretical basis for applying these new absorbents in chemical industry. The results in this thesis are shown as follows:1. Viscosities and densities of ethanolamine lactate ([MEA]L) and water were measured. The Data of viscosity and density of the IL were used tto calculate excess molar volumes (VE) and viscosity deviations (Δη). The strong interactions between the IL and water were revealed at molecular level. In addition, viscosity and density of the binary mixtures with respect to the mixture composition and temperature were correlated by Jouyban-Acree model.2. The absorption capacities of [MEA]L with different water contents, 30%,50%,70%, were determined. Meanwhile, viscosities and densities of aqueous [MEA]L solutions after absorption SO2 were also determined. The result shows that the solubility of SO2 in the aqueous [MEA]L solution increased with the increase of water content in the absorbent, and the viscosities and densities of aqueous [MEA]L solutions after absorption SO2 increase slightly. It is showen that the interactions among these molecules increase slightly after absorption SO2.3. A large-scale desulfurization device was designed and made to investigate the absorption of SO2 in simulated flue gas with aqueous [MEA]L solutions at different conditions, such as different mass fractions of water in absorbent, Vapor/Liquid ratio, different SO2 concentrations in flue gas, C02 concentration in flue gas, different inhibitor concentrations in the absorbent. The results showed that the SO2 removal rate increased with an increase of water content of aqueous [MEA]L solution; the SO2 removal rate increased with a decrease of the molar ratio of gas to liquid absorbent GIL; CO2 in the flue gas had no effect on absorption SO2 with aqueous [MEA]L solutions; sodium thiosulfate in absorbent has good inhibition effect on sulfite oxidation, on the other hand, it has no effect on absorption efficiency.4. The optimum conditions were found and circulatory SO2 absorption-desorption experiment by [MEA]L was performed on the device. The results showed that the solution after SO2 absorption could be regenerated by stream stripping, and reused for absorbing SO2 with a high removal rate.