3 replies to this topic

[smg@2021]

Hi,

 

I was trying to figure out a way to convert TBP @760 mmHg LV% distillation to ASTM D86 or TBP wt% for Crude in Pro/II.

 

Could anybody help me to convert TBP cut points to ASTM D86 in Pro-II? 

 

I tried entering crude assay in a stream (say S1) for given assay (TBP @ 760 mmHg LV%) and added it in a mixer with an outlet stream (say S2). But the inlet stream (S1) final TBP @760 mmHg results are different from what I entered in crude petroleum assay. 

 

 

 

[SilverShaded]

Ok, it is completely unclear what your are trying to do.  Crude Assays can not be converted to D86.  Only atmospheric boiling streams can.  Final boiling points are allmost allways an extropolation and that be why you get a different number.  If its a typical atmospheric column stream then final boiling points cannnot be accurately measured or predicted.  Its common practice to use 99% boiling points instead.

[smg@2021]

Ok, it is completely unclear what your are trying to do.  Crude Assays can not be converted to D86.  Only atmospheric boiling streams can.  Final boiling points are allmost allways an extropolation and that be why you get a different number.  If its a typical atmospheric column stream then final boiling points cannnot be accurately measured or predicted.  Its common practice to use 99% boiling points instead.

 

Lets take another example. I have Naphtha distillation D86 cut points and I want it to convert it to TBP cutpoints. How should I do that? 

[SilverShaded]

 

Ok, it is completely unclear what your are trying to do.  Crude Assays can not be converted to D86.  Only atmospheric boiling streams can.  Final boiling points are allmost allways an extropolation and that be why you get a different number.  If its a typical atmospheric column stream then final boiling points cannnot be accurately measured or predicted.  Its common practice to use 99% boiling points instead.

 

Lets take another example. I have Naphtha distillation D86 cut points and I want it to convert it to TBP cutpoints. How should I do that? 

 

All simulation programs have standard methods built in, it just a case of reporting the correct values.  When you enter data as D86 the program allways converts it to TBP for internal calcualtions.  If your simulation converged than you should have the values for TBP somewhere in the results.

Alternatively its relatively simple to do it in a spreadhseet using one of the API or other conversion methods, Riazi's book give a few options.

Be aware that D86-TBP-D86 conversions for light naphtha are appallingly inaccurate.

Edited by SilverShaded, 16 September 2021 - 10:13 AM.