# 3 kpa given feed contains 90 mol a and 10 mol b

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

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: te to contain 99.5 mol% anhydride and bottoms to contain 0.5 mol% acid. Vapor pressure data. Assumptions: Raoult's law to compute K-values from vapor pressure data. Constant molar overflow. Find: Number of theoretical plates needed if a reflux ratio, L/D = 1.6 times minimum. Analysis: First compute an equilibrium y, x curve using Raoult's law with the vapor pressure data. Eq. (2-44 ) applies, as well as the sum of the mole fractions in the phases in equilibrium. Thus, Ps T Ps T y y KA = A = A , KB = B = B (1, 2) xA P xB P yA + y B = 1 , xA + x B = 1 (3, 4) Equations (1) to (4) can be reduced to the following equations for the mole fractions of maleic anhydride (A) in terms of the K-values: 1 - KB (5, 6) , y A = KA x A KA - KB If the given vapor pressure data are fitted to Antoine equations, we obtain: xA = PAs = exp 16.6541 - PBs = exp 23.0155 - 4088.12 T + 203.924 9336.97 T + 321434 . (7) (8) Where vapor pressure is in torr and temperature is in oC. Solving, Eqs. (1) to (8), In solving the equations, P = 13.3...
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