Molar Volume gas mixture using Peng-Robinson Equation of State

#matlab #pengrobinson #thermodynamics #fugacity
Calculate the molar volume of a gas mixture consisting of 50 mol % propane (1), 20% n-butane (2), and 30% n-pentane (3) at 40 bar and 480 K using the Peng-Robinson equation of state.
Ismail Tosun (2021) , the thermodynamic of phase and reaction equilibria p.227
clc;clear;close all;
R=83.14; %cm3.bar/mol/K
P=40; %bar
T=480; %K
%propane(1)-nbutane(2)-npentane(3)
Tc=[369.9 425 469.8]; %Kelvin
Pc=[42.5 38 33.6]; %Bar
w=[0.153 0.199 0.251]; %acentric factor
x=[0.5 0.2 0.3]; %mole fraction
kij=[0 6.628e-4 1.937e-3;
6.628e-4 0 3.399e-4;
1.937e-3 3.399e-4 0];
kappa=0.37464+1.54226.*w-0.26992.*w.^2;
a=(1+kappa.*(1-(T./Tc).^0.5)).^2.*(0.45724.*R.^2.*Tc.^2)./Pc;
b=0.07780.*R.*Tc./Pc;