Characterization Of Acetamide Based Eutectic Ionic Liquids And Their Application In SO₂Absorption

With the development of flue gas desulfurization technology, ionic liquids showunique advantagesas as a new type of SO2absorbent. In this study, based on the existingresearch of ionic liquids, a series of acetamide-inorganic salt based eutectic ionic liquids(acetamide-inorganic salt EILs) are prepared, and their properties and applications in fluegas desulfurization are studied.In this paper, the prepared acetamide-inorganic salt EILs include acetamide-KSCN,acetamide-NaSCN, acetamide-NH4SCN, acetamide-LiCl, acetamide-ZnCl2. The physicaland chemical properties of these acetamide-inorganic salt EILs were determined,including melting point, thermal decomposition temperature, density, conductivity andviscosity. The optimum proportion of acetamide-inorganic salt EILs was determined andthe property change rules were analyzed and summed up as the corresponding equations.The SO2absorption performance and cycle performance of these acetamide-inorganicsalt EILs were studied, then the mechanism of absorption was analyzed. The results showthat the SO2absorption of acetamide-inorganic salt EILs dramatically decreased with theincreasing of temperature. The absorption amounts of acetamide-thiocyanate based EILswere higher than that of acetamide-metal halide based EILs. Among theseacetamide-inorganic salt EILs, acetamide-KSCN EILs are considered as promising SO2absorption agent because of the good performance of SO2absorption（20℃，0.588g/g）,low viscosity, good recycling performance and so on.Water is not only recognized as green solvents, but also indispensable impurities inionic liquids, affecting the chemical and physical properties of the ionic liquid. So thephysical and chemical properties of the aqueous solution of acetamide-KSCN EILs werestudied, including density, viscosity and electrical conductivity. The influence of water onthe SO2absorption performance and cycle performance are discussed. The resultsindicated that the aqueous solution of acetamide-KSCN EILs show good SO2absorptionperformance and physical properties when the mole fraction of water is0.428, and hasgood application prospect as a SO2absorption agent.