Question number 4 only

3) One thousand pounds per hour of a 40 wt% acetone (A)-60 wt% water (W) solution is to be reduced to 5 wt% acetone with 400 lbs/hr of 1,1,2-trichloroethane (TCE) as a solvent in a counter-current multistage contact operation. a) Determine the number of stages required for the separation. b) Find the intermediate concentrations of acetone in the extract and raffinate leaving each stage. c) Determine the flowrates of extract (E) and raffinate (Rn) using the graphical method and a component balance of your choice. Confirm your calculated balances using another component balance. d) What fraction of acetone (as % of the amount fed) would be recovered in the extract after two stages? 4) Using the feed and conditions defined in problem #3 design a cross-current extraction system in which 100 lbs/hr of solvent is used in each stage, e.g. initially consider a maximum of four stages (i.e 400/4) however if additional stages are needed to reach the same overall final composition do so (using more solvent as necessary) a) Determine the percent (solute) extraction for each phase (Into Stage - Out of Stage) % and overall percentage of solute extracted in each stage (Overall In - Removed in Stage) %. b) Which approach appears to be better - counter-current or cross current? Explain