Soave Redlich Kwong

In [1]:

## Redlich_Kwong Equation - for Mixtures
import pandas as pd
import numpy as np
from pvtpy.compositional import Chromatography, Component, properties_df
from pvtpy.units import Pressure, Temperature

## Redlich_Kwong Equation - for Mixtures import pandas as pd import numpy as np from pvtpy.compositional import Chromatography, Component, properties_df from pvtpy.units import Pressure, Temperature

Liquid Hydrocarbon Mixture¶

In [2]:

d1 = {
    'comp': ['methane','ethane','propane','butane','pentane','n-hexane'],
    'mole_fraction':[0.45,0.05,0.05,0.03,0.01,0.01]
}

c7_plus = Component(
    name = 'C7+', 
    molecular_weight=215,
    mole_fraction=0.4,   
    critical_pressure=285,
    critical_pressure_unit='psi',
    critical_temperature=700,
    critical_temperature_unit='farenheit',
    params={'acentric_factor':0.52}
)

ch1 = Chromatography()
ch1.from_df(pd.DataFrame(d1),name='comp')
ch1.plus_fraction = c7_plus

ch1.df(columns=['mole_fraction','acentric_factor'])

d1 = { 'comp': ['methane','ethane','propane','butane','pentane','n-hexane'], 'mole_fraction':[0.45,0.05,0.05,0.03,0.01,0.01] } c7_plus = Component( name = 'C7+', molecular_weight=215, mole_fraction=0.4, critical_pressure=285, critical_pressure_unit='psi', critical_temperature=700, critical_temperature_unit='farenheit', params={'acentric_factor':0.52} ) ch1 = Chromatography() ch1.from_df(pd.DataFrame(d1),name='comp') ch1.plus_fraction = c7_plus ch1.df(columns=['mole_fraction','acentric_factor'])

Out[2]:

	mole_fraction	acentric_factor
methane	0.45	0.0115
ethane	0.05	0.0995
propane	0.05	0.1523
butane	0.03	0.2002
pentane	0.01	0.2515
n-hexane	0.01	0.3013
C7+	0.40	0.5200

In [3]:

p1 = Pressure(value = 4000, unit='psi')
t1 = Temperature(value = 160, unit='farenheit')

p1 = Pressure(value = 4000, unit='psi') t1 = Temperature(value = 160, unit='farenheit')

In [4]:

ch1.soave_redlich_kwong_components_coef(t1)


ch1.df(columns=['mole_fraction','srk_a','srk_b','srk_alpha', 'acentric_factor'])

ch1.soave_redlich_kwong_components_coef(t1) ch1.df(columns=['mole_fraction','srk_a','srk_b','srk_alpha', 'acentric_factor'])

Out[4]:

	mole_fraction	srk_a	srk_b	srk_alpha	acentric_factor
methane	0.45	8688.770713	0.478495	0.686593	0.0115
ethane	0.05	21041.202832	0.723177	0.923015	0.0995
propane	0.05	35409.568072	1.004698	1.051035	0.1523
butane	0.03	52350.514587	1.292135	1.164088	0.2002
pentane	0.01	72002.574726	1.608655	1.264327	0.2515
n-hexane	0.01	93955.330354	1.943280	1.358148	0.3013
C7+	0.40	232235.747155	3.782751	1.489631	0.5200

In [5]:

ch1.soave_redlich_kwong_mix_coef()

ch1.soave_redlich_kwong_mix_coef()

Out[5]:

(90381.12778928163, 1.8891001828303455)

In [6]:

ma = ch1.apparent_molecular_weight()
ma

ma = ch1.apparent_molecular_weight() ma

Out[6]:

100.264435

In [7]:

ch1.soave_redlich_kwong.alpha

ch1.soave_redlich_kwong.alpha

In [8]:

A,B = ch1.soave_redlich_kwong.coef_AB(p1,t1)

print(A,B)

A,B = ch1.soave_redlich_kwong.coef_AB(p1,t1) print(A,B)

8.177439904015678 1.1364616583602605

In [ ]:

In [9]:

poly = ch1.soave_redlich_kwong.cubic_poly(p1,t1)
print(type(poly))
print(poly)

poly = ch1.soave_redlich_kwong.cubic_poly(p1,t1) print(type(poly)) print(poly)

<class 'numpy.polynomial.polynomial.Polynomial'>
-9.293346914459027 + 5.749433144732464·x¹ - 1.0·x² + 1.0·x³

In [10]:

roots = poly.roots()
print(roots)
roots[np.isreal(roots)].real

roots = poly.roots() print(roots) roots[np.isreal(roots)].real

[-0.22557549-2.52056284j -0.22557549+2.52056284j  1.45115098+0.j        ]

Out[10]:

array([1.45115098])

In [11]:

ch1.soave_redlich_kwong.estimate_densities(p1,t1, ma)

ch1.soave_redlich_kwong.estimate_densities(p1,t1, ma)

Out[11]:

{'rho': array([41.56560542])}

Gas Hydrocarbon Mixture¶

In [12]:

d2 = {
    'comp': ['methane','ethane','propane','butane','pentane','n-hexane'],
    'mole_fraction':[0.86,0.05,0.05,0.02,0.01,0.005]
}

c7_plus2 = Component(
    name = 'C7+', 
    molecular_weight=215,
    mole_fraction=0.0005,   
    critical_pressure=285,
    critical_pressure_unit='psi',
    critical_temperature=700,
    critical_temperature_unit='farenheit',
    params={'acentric_factor':0.52}
)

ch2 = Chromatography()
ch2.from_df(pd.DataFrame(d2),name='comp')
ch2.plus_fraction = c7_plus2

ch2.df(columns=['mole_fraction'], normalize=True)

d2 = { 'comp': ['methane','ethane','propane','butane','pentane','n-hexane'], 'mole_fraction':[0.86,0.05,0.05,0.02,0.01,0.005] } c7_plus2 = Component( name = 'C7+', molecular_weight=215, mole_fraction=0.0005, critical_pressure=285, critical_pressure_unit='psi', critical_temperature=700, critical_temperature_unit='farenheit', params={'acentric_factor':0.52} ) ch2 = Chromatography() ch2.from_df(pd.DataFrame(d2),name='comp') ch2.plus_fraction = c7_plus2 ch2.df(columns=['mole_fraction'], normalize=True)

Out[12]:

	mole_fraction
methane	0.863887
ethane	0.050226
propane	0.050226
butane	0.020090
pentane	0.010045
n-hexane	0.005023
C7+	0.000502

In [13]:

ch2.soave_redlich_kwong_components_coef(t1)

ch2.df(columns=['mole_fraction','srk_a','srk_b'])

ch2.soave_redlich_kwong_components_coef(t1) ch2.df(columns=['mole_fraction','srk_a','srk_b'])

Out[13]:

	mole_fraction	srk_a	srk_b
methane	0.863887	8688.770713	0.478495
ethane	0.050226	21041.202832	0.723177
propane	0.050226	35409.568072	1.004698
butane	0.020090	52350.514587	1.292135
pentane	0.010045	72002.574726	1.608655
n-hexane	0.005023	93955.330354	1.943280
C7+	0.000502	232235.747155	3.782751

In [14]:

ma2 = ch2.apparent_molecular_weight()
ma2

ma2 = ch2.apparent_molecular_weight() ma2

Out[14]:

20.027368156705165

In [15]:

ch2.soave_redlich_kwong_mix_coef()

ch2.soave_redlich_kwong_mix_coef()

Out[15]:

(8741.036982505435, 0.5539290826470736)

In [16]:

A,B = ch2.soave_redlich_kwong.coef_AB(p1,t1)

print(A,B)

A,B = ch2.soave_redlich_kwong.coef_AB(p1,t1) print(A,B)

0.7908653761199639 0.3332375750109206

In [17]:

poly = ch2.soave_redlich_kwong.cubic_poly(p1,t1)
print(type(poly))
print(poly)

poly = ch2.soave_redlich_kwong.cubic_poly(p1,t1) print(type(poly)) print(poly)

<class 'numpy.polynomial.polynomial.Polynomial'>
-0.2635460600983164 + 0.34658051970988435·x¹ - 1.0·x² + 1.0·x³

In [18]:

poly.roots()

poly.roots()

Out[18]:

array([0.03418411-0.53077109j, 0.03418411+0.53077109j,
       0.93163177+0.j        ])

In [19]:

p2 = Pressure(value = 4000, unit='psi')
t2 = Temperature(value = 160, unit='farenheit')
ch2.soave_redlich_kwong.estimate_densities(p2,t2, ma2)

p2 = Pressure(value = 4000, unit='psi') t2 = Temperature(value = 160, unit='farenheit') ch2.soave_redlich_kwong.estimate_densities(p2,t2, ma2)

Out[19]:

{'rho': array([12.93240769])}

In [ ]: