Chapter 10, Problem 10.18P

(a)

Interpretation Introduction

Interpretation:

To estimate the fugacity of isobutylene gas at 280 ⁰C and 20 bar

Concept Introduction :

For the given conditions, we first find Reduced Temperature, T_r and Reduced Pressure, P_r$T_r=\frac{T}{T_C}$

and

  $P_r=\frac{P}{P_C}$

At lower pressures, Fugacity Coefficient can be found by Virial equation

  $\varphi =\exp \left[\frac{P_r}{T_r}(B^0+\omega B^1\right]$

where the values of $B^0$ and $B^1$ are found as below,

  $B^0=0.083-\frac{0.422}{T_r^{1.6}}$

  $B^1=0.139-\frac{0.172}{T_r^{4.2}}$

Where,

R = Universal Gas constant

T = Temperature = 280 C = 553.15 K

T_c = Critical Temperature

P_c = Critical Pressure

  $\varphi$ = Fugacity Coefficient = $\frac{f}{P}$

P = Pressure = 20 bar

f = Fugacity

(b)

Interpretation Introduction

Interpretation:

To Estimate the fugacity of isobutylene gas at 280 ⁰C and 100 bar

Concept Introduction :

For the given conditions, we first find Reduced Temperature, T_r and Reduced Pressure, P_r $T_r=\frac{T}{T_C}$

and

  $P_r=\frac{P}{P_C}$

At higher pressures, Fugacity can be found by Lee Kesler correlation as given below,

  $\varphi =({\varphi }^0){({\varphi }^1)}^{\omega }$

where the values of ${\varphi }^0$ and ${\varphi }^1$ are found in thermodynamic tables

Where,

R = Universal Gas constant

T = Temperature = 553.15 K

T_c = Critical Temperature

P_c = Critical Pressure

  $\varphi$ = Fugacity Coefficient = $\frac{f}{P}$

P = Pressure = 100 bar

f = Fugacity