a) Show that the problem of flash vaporization of a multicomponent ideal mixture can be reformulated as suggested by Rachford and Rice (Doherty and Malone, 2001):

Equation (6-109) is solved iteratively for \(\phi\); all other variables are calculated explicitly from equations (6-110) to (6-112).

(b) Solve Example 6.2 using the Rachford-Rice method.

Data From Example 6.2:-

A liquid containing 50 mol% benzene (A), 25 mol% toluene (B), and 25 mol% o-xylene (C) is flash-vaporized at 1 atm and 373 K. Compute the amounts of liquid and vapor products and their composition. These components form ideal mixtures. The vapor pressures of the three components at 373 K are P_A = 178.8 kPa, P_B = 73.6 kPa, and P_C = 26.3 kPa. Therefore, for a total pressure of 1 atm and a temperature of 373 K, m_A = 1.765, m_B = 0.727, m_C = 0.259.

Transcribed Image Text:

f(0)=2, (m-1) 1+o(m, -1) Zi P =0 where m (6-109) P x i=1,2,...,C (6-110) 1+6(m, -1) y=mx, i=1,2,...,C (6-111) D=OF W = (1-0) F (6-112)