This preview shows page 1. Sign up to view the full content.
Unformatted text preview: y= Calculations for other values of the benzene mole fraction in the bottoms can be made in the same manner. (f) At total reflux, there is no distillate, but there is a boilup. The moles of distillate per 100 moles of feed = 0. Exercise 7.13
Subject: Distillation of a mixture of benzene and toluene at 101 kPa for specified reflux ratio and product compositions. Given: Feed of 30 kg/h of saturated liquid feed containing 40 mass% benzene and 60 mass% toluene. Distillate to contain 97 mass% benzene and bottoms to contain 98 mass% toluene. Reflux ratio = 3.5 and feed is to optimal stage. Table of vapor-liquid equilibrium data in mole fractions. At 101 kPa. Assumptions: Total condenser and partial reboiler. Saturated liquid reflux. Constant molar overflow. Find: (a) Flow rates of distillate and bottoms. (b) Number of equilibrium stages needed. Analysis: First solve the material balance in mass units. Then convert to moles and mole fractions so that the McCabe-Thiele method can be used for part (b). Overall to...
View Full Document