A feed mixture containing 50 wt% n-heptane and 50 wt% methylcyclohexane (MCH) is to be separated by liquid-liquid extraction into one product containing 92.5 wt% methylcyclohexane and another containing 7.5 wt% methylcyclohexane, both on a solvent-free basis. Aniline will be used as the solvent. Using the equilibrium data given below and the graphical method of Maloney and Schubert:

(a) What is the minimum number of theoretical stages necessary to effect this separation?

(b) What is the minimum extract reflux ratio?

(c) If the reflux ratio is 7.0, how many theoretical contacts arerequired?

Transcribed Image Text:

LIQUID-LIQUID EQUILIBRIUM DATA FOR THE SYSTEM n-HEPTANE/METHYLCYCLOHEXANE/ ANILINE AT 25"CAND AT I ATM (101 kPa) Solvent Layer Hydrocarbon Layer Pounds Weight Percent Pounds Weight Percent Aniline/ Pound Aniline/ Мсн, Solvent- Pound Мсн, Solvent- Solvent- Solvent- Free Mixture Free Mixture Free Basis Free Basis 0.0799 0.0 0.0 15.12 13.72 0.0836 I1.8 9.9 20.2 0.087 33.8 11.5 11.34 0.0894 37.0 23.9 0.094 50.6 9.98 36.9 0.0952 60.0 9.0 44.5 0.0989 0.1062 67.3 8.09 50.5 76.7 6,83 66.0 74.6 0.1111 84.3 6.45 6.0 0.1135 88.8 79.7 90.4 5.9 82.1 0.116 0.1272 0.135 96.2 5.17 93.9 100.0 4.92 100.0