Excel library for process calc's including distillation

[carlo.stenali]

yes,
you have to change only the constant of conversion.

[stawad]

I wish to calculate the speed of sound for a vapor + liquid mixture,
the application would be the Mach number in a flare network,
I know that Prode Properties has a specific method for calculating the speed of sound in mixed phases,
which are the basis of that method ?

[carlo.stenali]

PRODE PROPERTIES calculates the speed of sound in mixed (vapor + liquid) phase
with HEM (Homogeneous Equilibrium Model)

HEM method is reliable for a large range of applications including flare networks,

note that PRODE PROPERTIES has methods to design/rate pipes / pipelines which can be utilized to simulate a flare network.

[stawad]

thanks Carlo,
does HEM method (as coded in PRODE PROPERTIES) assume the same or different velocities for vapor and liquid phases ?

[carlo.stenali]

yes,
in HEM (Homogeneous Equilibrium Model) vapor and liquid phases form a homogeneous mixture traveling at same speed,

if you wish to model a fluid forming a non-homogeneous mixture use HNE (Homogeneous Non-equilibrium Model) instead,

Carlo

[acar]

Carlo,
I have to calculate the speed of sound for a vapor + liquid mixture and I think to use Extended Peng Robinson Model available in PRODE PROPERTIES,
does that model give consistent results for a natural gas mixture (C1-C9 + CO2..) ?

[carlo.stenali]

yes,
for natural gas mixtures I would select the Extended Peng Robinson or the Extended Soave Redlich Kwong versions available in PRODE PROPERTIES,
you may also consider BWR or (when water-alcohools as methanol etc.) present the different variants of CPA.

For calculating the speed of sound the procedure needs to evaluate density, enthalpy and entropy
so when selecting the model you should consider the accuracy
given by the different models for these properties.

[cbadia]

Carlo,
I see that predicted speed of sound is (very) sensible to selected models for enthalpy and entropy,
what happens if I mix different models as, say,
Peng Robinson for fugacity and Lee Kesler for enthalpy ?

[cbadia]

Carlo,
I see that predicted speed of sound is (very) sensible to selected models for enthalpy and entropy,
what happens if I mix different models as, say,
Peng Robinson for fugacity and Lee Kesler for enthalpy ?

[carlo.stenali]

you can mix models if you think that a model gives better accuracy on some property,
in PRODE PROPERTIES you can define packages to include
different models for Fg,H,S,V,Visc, etc.this allows a great flexibility
to manage mixtures with non-standard behaviour,
for hydrocarbons I usually select the extended versions (5 parameters) of
Peng Robinson and Soave Redlich Kwong but other EOS
can be defined as well.

[carlo.stenali]

you can mix models if you think that a model gives better accuracy on some property,
in PRODE PROPERTIES you can define packages to include
different models for Fg,H,S,V,Visc, etc.this allows a great flexibility
to manage mixtures with non-standard behaviour,
for hydrocarbons I usually select the extended versions (5 parameters) of
Peng Robinson and Soave Redlich Kwong but other EOS
can be defined as well.

[cbadia]

thanks Carlo,
some papers suggest Lee Kesler for enthalpies of natural gas mixtures,
so I wish to compare and see the results