Butanone Oxime Extraction From Aqueous Ammonium Sulfate Solution Using Ionic Liquid

In industry, butanone oxime is generally synthesized by the reaction between butanone and hydroxylamine. But aqueous ammonium sulfate solution that contains quite a little butanone oxime is also produced as a by-product. Thus it is necessary to find appropriate solvents to extract and recycle butanone oxime from the solution. Ionic Liquids(ILs) are considered to be the most promising alternatives to conventional organic solvents as "green solvents" and show a good application prospect in separation territory. In this study, the ionic liquid 1-Butyl-3-methylimidazolium hexfluorophosphate(Bmim][PF6]) is used to extract and recycle butanone oxime from ammonium sulfate aqueous solution to replace conventional organic solvents, decrease the cost of energy and the loss of extractant during the extraction process and improve the quality of ammonium sulfate.The main contents are as follows:1. A reliable analysis method of [Bmim][PF6] and butanone oxime in aqueous solution using HPLC(high performance liquid chromatography) is proposed. The liquid-liquid equilibrium(LLE) data for the system of [Bmim][PF6]+butanone oxime+water are determined at 303.15 K,313.15 K, and 323.15 K and atmospheric pressure. The distribution coefficient and selectivity of butanone oxime are also calculated from the experimental data. Moreover, the influences of temperature and the concentration of butanone oxime in the initial aqueous solution on extraction effect and mutual solubilities between [Bmim][PF6] and water are investigated. The reliability of experimental data are ascertained by using both Othmer-Tobias and Hand equations. Finally, the NRTL equation is used to correlate the LLE data and the correlation accuracy is analyzed.2. The LLE data for the system of [Bmim][PF6]+ammonium sulfate+water are determined at 303.15 K,313.15 K, and 323.15 K and atmospheric pressure. The influences of temperature and the concentration of ammonium sulfate in the initial aqueous solution on mutual solubilities between [Bmim][PF6] and water are investigated. The reliability of experimental data are ascertained by using both Othmer-Tobias and Bachman equations. Based on the binary interaction parameters of NRTL equation that correlated previously, the NRTL equation and Pitzer electrolyte solution model are used to predict the LLE data and the prediction accuracy is analyzed.3. A reliable analysis method of butanone oxime in ammonium sulfate aqueous solution using UV-Vis(ultraviolet and visible) spectrophotometry is proposed. The LLE data for the system of [Bmim][PF6]+butanone oxime+water+ammonium sulfate are determined at 303.15 K and atmospheric pressure. The distribution coefficient and selectivity of butanone oxime are also calculated from the experimental data. Moreover, the influences of extraction time and the concentration of butanone oxime and ammonium sulfate in the initial aqueous solution on extraction effect are investigated. The reliability of experimental data are ascertained by using both Othmer-Tobias and Bachman equations. Finally, the Eisen-Joffe equation that Rajendran improved is used to correlate the LLE data and the correlation accuracy is analyzed.4. The extraction process of butanone oxime from ammonium sulfate aqueous solution by using [Bmim][PF6] is designed. The amount of theoretical stages and [Bmim][PF6] that the extraction required are also determined. The flow diagram of extraction process is drawn. At last, box-type mixer settler is selected as the appropriate liquid-liquid extraction equipment, and its process design is accompolished.