6 replies to this topic

[chem101]

Hi,

I hope you all are fine and healthy. I need some one to help me with following issue. 

If you have followings composition

C1   85

C2   5

C3   4

C4   3

C5   1.5

C6+  1.5

How would one need to enter C6+ composition in Hysys Simulation?

 

Thank you for anyone help in advance

SS

[PaoloPemi]

depending from data type and specifications (for example C6+ could be the result of GC measurement) 

I utilize a rule to convert C6+ to real components ,

for example GPA 2261 suggest to split the C6+ fraction into several components, typically 50% n-Hexane, 25% n-Heptane, 25% n-Octane,

here you can find an example about how to split a C6+ value from GC measurement

 

www.prode.com/docs/proind.pdf

 

you may follow a similar procedure with Hysys

Edited by PaoloPemi, 28 August 2013 - 09:13 AM.

[equilibrium]

Refer to "Characterizing Hydrocarbon Plus Fractions, Whitson, 1983"

 

The values in the above paper take into consideration the presence of parrafin, napthene, and aromatic (PNA) contributions and data is available from C6+ to C45+.

 

I have also compared Whitson to GPA 2261 in regards to the C6+ fraction only and they are both very comparable to the other.

[Propacket]

You need to generate a hypo component in Hysys. Minimum properties required to generate the hypo component are any two of density, mol weight and and normal boiling point.  

[gegio1960]

The suggestion from Propacket (and the other Members) is correct, but in the real world you usually don't have the 2 additional parameters.

It is up to the sensibility of the designer (and, of course, the nature of the process and the relative amount of unknown) to understand/decide which are the kind of possible C6+ components that could have more impact on the design.

In case of uncertainties that could compromise the design, it is better to insist to obtain a better characterization and/or to declare the assumptions made.

That's required to avoid mistakes and to justify the design in case of claims.

Good luck!

[Pilesar]

Natural streams usually have a normal distribution of components. But a stream from another processing facility may be artificially formed. Using a rule of thumb to get a normal distribution may bite you depending on what you are doing with it. Try modeling your system with the C6+ as all hexane. Then change the characterization to all octane. Does it make a difference? If so, use the conservative choice. This is a very minor component in your stream and your design should be robust enough to handle reasonable variations.

[Propacket]

Actually this type of characterization (C6+, C7+ etc.) is performed in wellhead fluid analysis reports. You should study this report for your wellhead fluid. You will find that the report will provide the complete split of C6+. In addition the report will also give you the parameters i was referring.