PROBLEM 5 : Vapor Liquid Equilibria

Termodinamika Teknik Kimia, 20 April 2015

1. Read the paper on VLE Dont Gamble with Physical Properties for Simulations by Eric C. Carlson,

Chemical Engineering Progress, October 1996, p. 35-46. Categorize the models into one or more

following class of VLE Models : equation of state, specific correlation, activity coefficient model,

fugacity coefficient model, predictive model, ways to optimize the parameters in the model such as

using a binary interaction parameter, etc.

2. You are going use the van der Waals equation of state (VdW EoS) to generate the P-x,y diagram (P

as a function of vapor and liquid compositions) of propane and n-butane binary mixture at 303.15

K. You decided not to write a computer program, but you are going to learn an available computer

anyway. The procedure is as follows:

Prepare an algorithm for bubble point calculation

Derive fugacity coefficient for component i in the mixture using VdW EOS

Read the given FORTRAN computer program given to you. Please compare the fugacity coefficient

vs pressure as seen on problem 4.

Write a FORTRAN computer program for bubble point calculations, using Raoults law to obtain the

P and y estimates required for starting the iteration

Check the results of your calculation by plotting the calculated data points and compare them with

experimental data points reported by Seong et al. (J. Chem. Eng. Data, 2008, 53, 27832786).