9 from the total condenser and xb 0625 the measured

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: LD/VB = 0.8. Combining this with Eq. (3), VB = 125 moles/100 moles of feed, which is close to the analytical value. Exercise 7.24 (continued) Exercise 7.25 Subject: Rectification of a mixture of benzene and chlorobenzene at total reflux. Given: Feed of 100 kmol of 20 mol% benzene and 80 mol% chlorobenzene. Column has 4 theoretical plates, a total condenser, a reflux drum, and a still to vaporize the feed. At an operating pressure of 1 atm, relative volatility of benzene with respect to chlorobenzene = = 4.13. Operate at total reflux with holdups only in the reflux drum and the still. Want liquid in the still with 0.1 mol% benzene. Assumptions: Perfect mixing to give uniform compositions in the reflux drum and the still. Find: Moles of liquid in the still at steady state. Analysis: This exercise can be solved analytically or graphically. Since benzene is the more volatile component, Eq. (7-3) gives the equilibrium relation at the still or any of the 4 plates, n, as, yn = xn 4.13xn = 1 + xn ( - 1) 1 + 313xn . (1) At total reflux, numbering stages up from the bottom,...
View Full Document

This note was uploaded on 09/08/2008 for the course CHE 244 taught by Professor Selebi during the Spring '06 term at Lehigh University .

Ask a homework question - tutors are online