Q1. Aniline is used to extract methylcyclohexane (MCH) from a binary solution with 70% heptane by a single-stage extractor: Show all of your work, including on the attached LLE diagram.
a) If enough aniline is added to dilute the heptane by a factor of 7, what are the compositions of the two phases resulting from the LLE phase split in the stage?
b) If you started with 100 kg of the MCH-heptane solution, how much MCH comes out with the raffinate?
Q2. Air fed at 150 psia is separated with a hollow-fiber membrane with oxygen selectivity of 8 for 60% recovery at 40% concentration using a vacuum pump. The feed is introduced to the bore (Side) of the fibers where is cannot be well-mixed, and the permeate moves radially in the outward direction.
a) Draw and label clearly, then find the retentate (i.e., reject) concentrations.
b) Estimate the change in performance if the pump fails, when the membrane module operates as a counter-current system though still not perfectly mixed on the permeate side.
Q3. A packed column 3.5 m high with 1.5 m2 cross-section scrubs SO2 (1.6 vol%) from air entering at 0.062 kmol/s with pure water at 2.2 kmolis, giving ya = 0.004. If the sulfur dioxide partition (or distribution) coefficient is 40, find:
a) Number of overall gas-based transfer units.
b) Overall height of a gas-based transfer unit.
Q4. Ten ideal stages in a continuous counter-current process are sufficient to recover 98% of copper sulfate from a copper ore (inert carrier solids) slurry. The feed begins with 1.7 tons/hr of 70% solution (aqueous salt, plus inert solids retained in addition to that) and retains 20 tons of solution/hr. The aqueous solution product of copper sulfate exits 10%.
