| SO2 existed in almost all industrial enterprises would bring about the serious damage to the body and animal and plants and the whole ecosystem. So it is nessary and important to remove SO2 before emission of flue gas, to bring down the pollution to the environment. Technology to desulfurization of sulfur dioxide is applied extensively. Among these technologies the wet oxidation desulfurization for sulfur dioxide are widely used in many industrial production. The aqueous catalyzed oxidation desulfurization based on metal ions as catalyst is one of the wet oxidation desulfurization for sulfur dioxide, it own many advantages, such as high desulfurization performance and faster reaction rate, however, the reaction is taking place in aqueous phase causes many problems, it is difficult to separate the product after desulfurization reaction from catalyst in the reactant, what is more, the value of the byproduct is lower. Meanwhile it is necessary to add bases and fresh desulfurization agent continuously. It results in a great quantity loss of the catalyst. Therefore, it is of great significant to explore new green process of wet flue gas desulfurization process.Based on the designability of ionic liquids, the Fe-based ionic liquid was composed in this work. Based the Fe-based ionic liquid (Fe-IL), the system which own Fe-IL,water and ethanol is established, and used to the craft of flue gas desulfurization. The Fe-IL was synthesized directly by mixing 1:2 mole ratio of 1-butyl-3-methylimidazolium([Bmim]Cl) and FeCl3·6H2O at room temperature. The Fe-IL characterized by FT-IR illustrated its hydrophobicity. By elemental analysis the structure of the Fe-IL was [Bmim]Fe0.9Cl4.7. Raman spectrum indicated that the iron in the Fe-IL exists in the shape of FeCl4-Flue gas desulfurization process was carried out in the ternary system of Fe-IL,water and ethanol. The influence of the flow, sulfur dioxide concentration, pH, reaction temperature, liquid water content and oxygen was investigated, which puts more significant influence on desulfurization efficiency. The results show that when the entrance flow rate is 150mL/min, sulfur dioxide concentration 2270 ppm, The pH 2.0 and liquid water content 22.7%, the desulfurization efficiency is best. Reaction kinetics study present that reaction series to concentration of the Fe(Ⅲ) and Fe(Ⅱ) are-0.5, the increasing of Fe(Ⅲ)/Fe(Ⅱ) concentration put negative effect on desulfurization reaction. Reaction activation energy is 63.26 kJ/mol. The optimal pH in this condition is 2.0.After desulfurization the reactant solution was heated to remove ethanol, a two-separated phase between the Fe-IL and water was formed and the product of desulfurization was dissolved in the water phase, which realized to separate the product of desulfurization and catalyst. FT-IR spectrum indicte that the Fe-IL keep the similar chemical structures, and can be used desulfurization characterized by FT-IR illustrated did not change,it can be reused.In general, the Fe-IL could be used as catalyst to application to desulfurization of sulfur dioxide, and it is a green flue gas desulfurization technology. |
PDF Full Text Request