The liquid–liquid extractor in Figure 8.1 operates at 100F and a nominal pressure of 15 psia. For the feed and solvent flows shown, determine the number of equilibrium stages to extract 99.5% of the acetic acid, using the NRTL equation for activity coefficients. The NRTL constants may be taken as follows, with: 1 = ethyl acetate; 2 = water; and 3 = acetic acid.

Compare the computed compositions of the raffinate and extract products to those of Figure 8.1.

I 1 1 2 J 23 3 Bij 166.36 643.30 -302.63 Bji 1190.1 -702.57 -1.683 ij 0.2 0.2 0.2