crude oil unit simulation

[aady001]

Hello for every one .. When I need to do simulation of crude distillation unit by aspen hysys or aspen plus or any other simulator, which data i should use in the assay of the crude oil : the true boiling point data or simulated distilation data.
Thanks for All....

 

[EmmanuelTop]

Normally you would use true boiling point (TBP) data. You can choose which type of assay to use from the drop down list (Aspen HYSYS):

See also:

http://inside.mines.edu/~jjechura/Refining/Crude_Tower_Simulation-HYSYS_v8.6.pdf

http://inside.mines.edu/~jjechura/Refining/Crude_Tower_Simulation-AspenPlus_v8.6.pdf

Dejan IVANOVIC
Process Engineer, MSChE

 

[aady001]

Thank you for the reply, but the simulated distillation data in the assay report contains the detailed distillation ( e.g. 1,2,3......to about 90 % of crude with temp. , while the true boiling point data containes only the cuts (HN, LN, Kerosene.......) with temperature. Is this mean that used TBP will result less accurate or not?

 

[EmmanuelTop]

The "assay" by definition contains TBP distillation points observed in the laboratory during the actual experiment. This data is not obtained by process simulation - unless you are talking about someone else's simulation file.

TBP curve is a continuous curve, so it is possible to have tabular data expressed for each % distilled (if one wishes to). See below. You could assign the value of temperature for each % of distilled sample. The more values you enter in TBP characterization table, the more accurate simulation will be.

Cuts are cumulative yields of products estimated from TBP curve, however different in reality due to non-ideal separation in atmospheric crude towers. This non-ideality is usually expressed by 5% D86 temperature of heavier product minus 95% D86 temperature of the adjacent lighter product. You can read more in Watkins' and Jones' books, some info also in the link below.

https://www.ch2m.com/sites/default/...ss – Fundamental Concepts _no appendexes_.pdf

Dejan IVANOVIC
Process Engineer, MSChE

 

[EmmanuelTop]

See also pages 5, 6, and 7 of example assay:

http://www.maerskoil.com/about-us/documents/sales/alshaheenassay.pdf

Dejan IVANOVIC
Process Engineer, MSChE

 

[aady001]

Thank you for all reply. In my assay rport which data i select in the following

 

[EmmanuelTop]

Use the blue line from the chart - this is your TBP data. Pick temperatures and then read % distilled.

After entering TBP data, define the cuts in the simulator in the same way they are defined in the first table (i.e. IBP-70, 70-140, 140-190, etc.), and see how good predictions you get (compare cumulative yields from the simulator vs. yield from the first table above).

Dejan IVANOVIC
Process Engineer, MSChE

 

[aady001]

Thaaaanks