Hydrate formation temperature with Prode Properties 1

[OldDoc]

In some cases I need to calculate hydrate formation temperature ( or hydrate formation pressure ) for natural gas mixtures + inhibitors as methanol , glycol etc.
I have the base version of Prode Properties 1.2C4 which includes two models (PRX-NRTL-HV + PRX-CPA-NRTL-HV) for hydrates,
Prode works well but includes hydrate BIPs only for a few inhibitors, do you know how to add BIps for new inhibitors ?

 

[apetri]

those BIPs are difficult to calculate and I suspect the data regression utility can't help...
probably you already know there are versions with different hydrate models, maybe these include more inhibitors...

 

[PaoloPemi]

OldDoc, unfortunately the base version doesn't include a data regression utility for hydrates,
the only way (which I know) to calculate those values (with base version) is to run an external minimizer, could be Excel, Matlab, Mathcad etc.
the function to minimize could be the sum of errors (for a certain number of points)
|calculated hydrate temperature - measured hydrate temperature|
the variables are the different BIPs which you can modify (programmatically) via VBA or another language,
according my experience it is very slow.

 

[georgeverghese]

Very likely I wont be able to help; which inhibitor are you looking at to study? All of the inhibitors I know of have -OH or -O- functional groups.

 

[OldDoc]

thanks all,

apetri, if possible I would stay with base version which probably includes more than I need (except for inhibitors)

PaoloPemi, thanks for advice, I'll test the method.

georgeverghese, I wish to evaluate a few polar compounds (alcohols and glycols which work as inhibitors by bonding to water molecules) I have some P, T data and use Prode to extrapolate.

 

[georgeverghese]

Some companies sell proprietory hydrate inhibitors to the large multinationals generically called LDKHI - low dosage kinetic hydrate inhibitors. They claim large hydrate formation depression dT for low doses - these do not inhibit hydrate formation permanently but retard the reaction rate - very expensive.

 

[OldDoc]

no experience with polymers etc. injected into water phase (LDHI),
we use mainly (traditional) methanol or glycol based inhibitors ...