Cross-flow and countercurrent flow liquid liquid extraction

D15. The equilibrium data for extraction of acetic acid (A) from water (D) into isopropyl ether (S) is given in Table 14-2. We have 1,000 kg/hr of a feed that is 40 % A and 60 % D. This feed is extracted with a total of 1,000 kg/hr of pure isopropyl ether in a two- stage system. a. If a cross-flow system is used with 500 kg/hr of isopropyl ether into each stage, find the extract compositions, the final raffinate composition and the raffinate flow rate leaving the system. b. If a two-stage counter current system is used with a solvent flow rate of 1,000 kg/hr, find the extract composition, the raffinate composition and the raffinate flow rate. If the difference point is off the page, tape another sheet of paper to the first sheet. c. Compare the cross-flow and countercurrent systems. Table 14-2. Equilibrium data for water-acetic acid-isopropyl ether at 20 C and 1 atm Water Layer, wt % Isopropyl Ether Layer, wt% Water Isopropyl Ether *S Acetic Acid *A Acetic Acid Water Isopropyl Ether y's 0.69 1.41 2.89 6.42 13.30 25.50 36.70 44.30 46.40 98.1 97.1 95.5 91.7 84.4 71.1 58.9 45.1 37.1 1.2 1.5 1.6 1.9 2.3 3.4 4.4 10.6 16.5 0.18 0.37 0.79 1.93 4.82 11.40 21.60 31.10 36.20 0.5 0.7 0.8 1.0 1.9 3.9 6.9 10.8 15.1 99.3 98.9 98.4 97.1 93.3 84.7 71.5 58.1 48.7 Points on the same horizontal line are in equilibrium. Source: Treybal (1968)