Example 05.22a VLE of Hexane-Butanone-2 Via UNIFAC - Step by Step

Calculate the vapor-liquid equilibrium of the system n-hexane (1) - 2-butanone (2) at 60°C for a mole fraction of x1 = 0.5 with the help of the UNIFAC method assuming ideal behavior of the vapor phase.

System: n-hexane (1) - 2-butanon (2)

Definitions:

System temperature:

Pure component vapor pressures:

Composition:

Structural information:

Groups:

Subgroup 1 CH3

Subgroup 2 CH2

Subgroup 3 CH3CO

Maingroup 1 CH3

Maingroup 2 CH2CO

Subgroup i belongs to maingroup nordi:

Number of subgroups of type i

in component j (ni,j):

R- and Q-values for subgroups:

Interaction parameters between

maingroups:

Calculation of the combinatorial part (Guggenheim and Stavermann):

Relative van der Waals volume

and surface of the components:

Calculation of the residual part:

Mixture:

Calculation of group fractions in the mixture:

Calculation of group surface fractions

in the mixture:

Group activity coefficients in the mixture:

Pure Components:

Calculation of group fractions in the

pure components:

Calculation of group surface fractions

in the pure components:

Group activity coefficients in the

pure components:

Calculation of the activity coefficients:

Calculation of the total pressure:

Calculation of the vapor composition:

Calculation of the K-factors:

Calculation of the separation factors: