For parts (c) and (d), ethyl acetate is used to extract acetic acid from water as part of a process to create purified acetic acid. The feed to the liquid-liquid extraction process is 300 lb/h of a solution that is 65% acetic acid and 35% water. The solvent is pure ethyl acetate at a flowrate of 230 lb/h. The process produces an extract containing 40% acetic acid. Note that in the solvent and carrier liquids may be on opposite sides of the attached ternary phase diagram from where they typically are in our book. It won't make the problem any harder to solve. c) (10 points) How many equilibrium stages are required for this separation? d) (10 points) In this liquid-liquid extraction process, we produce an extract that contains a lower mass fraction of acetic acid than the feed contained. Since we are trying to purify acetic acid, why is this process beneficial? What further processing should be done to purify the acetic acid? (Hint: The normal boiling points of the 3 components are: 244.2°F for acetic acid, 170.8°F for ethyl acetate, and 212°F for water)
