# Problem 14.01 Joule-Thomson Coefficient of Nitrogen Using the Virial Equation and the SRK EOS¶

What is the Joule-Thomson coefficient of nitrogen at 150 K and 10 atm? Use a) the Tsonopoulos virial method, and b) the SRK equation of state.

## Solution¶

This requires configuring both phase objects and calling the appropriate method only.

:

from scipy.constants import atm
from thermo import ChemicalConstantsPackage, SRKMIX, CEOSGas, VirialCSP, VirialGas
fluid = 'nitrogen'
constants, correlations = ChemicalConstantsPackage.from_IDs([fluid])

T = 150
P = 10*atm

:

model = VirialCSP(Tcs=constants.Tcs, Pcs=constants.Pcs, Vcs=constants.Vcs,
omegas=constants.omegas, B_model='VIRIAL_B_TSONOPOULOS',
C_model='VIRIAL_C_ZERO')
virial_gas = VirialGas(model=model, T=T, P=P, zs=, HeatCapacityGases=correlations.HeatCapacityGases)
print(f"The Joule Thomson coefficient of nitrogen for the virial prediction is {virial_gas.Joule_Thomson():g} K/Pa")

The Joule Thomson coefficient of nitrogen for the virial prediction is 9.48161e-06 K/Pa

:

eos_kwargs = dict(Tcs=constants.Tcs, Pcs=constants.Pcs, omegas=constants.omegas)
gas = CEOSGas(SRKMIX, HeatCapacityGases=correlations.HeatCapacityGases, eos_kwargs=eos_kwargs)
print(f"The Joule Thomson coefficient of nitrogen for the SRK prediction is {gas.Joule_Thomson():g} K/Pa")

The Joule Thomson coefficient of nitrogen for the SRK prediction is 2.13403e-06 K/Pa