Research On The New Separation Method For2-Butanol-Water

2-Butanol（SBA）, as an important organic chemical raw material and industrialsolvent, is widely used as emulsifying agent, dehydrating agent, detergent andproduction of methyl ethyl ketone（MEK）. At atmospheric pressure, SBA can formazeotrope with water, which can’t be separated by conventional distillation. Inindustry, the azeotropic distillation to separate2-butanol from water consumesexcessive amounts of energy. This paper studies the separation of such binaryazeotrope by the salting-out extraction and extractive distillation. The researchcontents have been performed in this thesis as follows:1. Liquid-liquid equilibrium: First, the salting-out agent is selected by selectingsalt rule and experimental study. The inorganic salts include potassium fluoride,potassium carbonate and ammonium sulfate. Second, the research on liquid-liquidequilibrium for2-butanol-water-inorganic salt systems: The LLE data for system of2-butanol-water-KF,2-butanol-water-K₂CO₃and2-butanol-water-（NH₄）₂SO₄aremeasured at25℃. The results show that: The separation effect of KF is the best,followed by K₂CO₃. Finally, the LLE model research for2-butanol-water-inorganicsalts: A theoretical calculation of liquid-liquid equilibrium data was calculated byusing the Pitzer theory to get water activity in the water phase and by NRTL, Wilsonand UNQUAC for the organic phase. We can choose the most suitablethermodynamic model for the system of2-butanol-water-KF,2-butanol-water-K₂CO₃and2-butanol-water-（NH₄）₂SO₄, which can be used to direct the process design.2. Vapor-liquid equilibrium: The solvent is selected by extraction solventqualitative rule. On this basis, ethylene glycol, diethylene glycol and triethyleneglycol are selected as extractant for the separation of2-butanol-water system. Thevapor-liquid equilibrium data for2-butanol-water system are measured at normalpressure. Integral test is adopted to test the thermodynamics consistency. The VLEdata for system of2-butanol-water-solvents are determined at101.325kPa with themass ratios of solvent to2-butanol-water of0.5:1,1:1and2:1, respectively. Theresults show that, all of the solvents proposed in this thesis can increase the relative volatility of2-butanol-water obviously, especially the solvent of ethylene glycol.3. Simulation on separation of2-butanol-water azeotropic mixture: On the basisof liquid-liquid equilibrium and vapor-liquid equilibrium, the separation of2-butanol-water azeotropic mixture is simulated. The feasibility of separating of2-butanol-water azeotropic mixture is demonstrated by the salting-out extractionprocess with aqueous potassium carbonate. Meanwhile, the operating condition isdetermined. For the extractive distillation process using ethylene glycol as the solvent,the best technological parameters are selected by sensitivity analysis of Aspen Plussimulation software.