*Answers to problems with an asterisk are at the back of the book. D1. We are separating a mixture of methanol and water in a flash drum at 1.0 atm pres- sure. Equilibrium data are listed in Table 2-7. TABLE 2-7. Vapor-liquid equilibrium data for methanol water (p = 1 atm) (mol%) Methanol Vapor Temp., C Methanol Liquid 0 0 2.0 4.0 6.0 8.0 10.0 15.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 95.0 100.0 13.4 23.0 30.4 36.5 41.8 51.7 57.9 66.5 72.9 77.9 82.5 87.0 91.5 95.8 97.9 100.0 100 96.4 93.5 91.2 89.3 87.7 84.4 81.7 78,0 75.3 73.1 71.2 69.3 67.6 66.0 65.0 64.5 Source: Perry et al. (1963), p. 13-5. a. Feed is 60.0 mol% methanol, and 40.0% of the feed is vaporized. What are the vapor and liquid mole fractions and flow rates? Feed rate is 100 kmol/h. b. Repeat part a for a feed rate of 1500.0 kmol/h. c. If the feed is 30.0 mol% methanol and we desire a liquid product that is 20.0 mol% methanol, what VF must be used? For a feed rate of 1000.0 lbmol/h, find product flow rates and compositions. d. We are operating the flash drum so that the liquid mole fraction is 45.0 mol% methanol. L = 1500.0 kmol/h, and V/F = 0.2. What must the flow rate and compo- sition of the feed be? e. Find the dimensions of a vertical flash drum for Problem 2.Dic. Data: P. = 1.00 g/cm. Pre = 0.7914 g/cm", MW= 18.01, MW 32.04. Assume vapors are ideal gas. f. If z = 0.4, p = 1.0 atm, and T g. If F = 50.0 mol/h, z = 0.8, p = 1.0 atm, and ym = 0.892 mole fraction methanol, find m 77C, find V/F, X and ym drum V. L, and x. T osene. Problem Answers to Selected Problems Chapter 2 2.D1. a. y =0.77.x=0.48 b. V = 600.0 and L = 900.0 c. V/F = 0.25, y = 0.58 d. F= 37.5 kmol/h e. D = 1.705 ft. Use 2.0 ft. L ranges from 6.0 to 10.0 ft. f. V/F = 0.17 g. x = 0.756, V = 16.18 mol/h. L = 33.82 moh Hint Worth