3 replies to this topic

[CHEMSTRONG]

Dear Sir,

Can anyone help me in getting normalisation formula for Composition in ASPEN HYSYS/PLUS or any high fidelity simulator. hwo does it work generally ?

Please help me in this.

 

Regards,

Chetan Chavan 

[PaoloPemi]

if you mean the normalization of feed fractions  in many simulators these are normalized to 1.0 or 100 or ...(depending from selected range) with

 

z1(norm) = z1 / (z1 = z2 + z3 ... +zn)

 

but i suppose you question is different, can you provide additional details ?

[CHEMSTRONG]

Dear Sir,

 

Thanks a lot for your reply.

 

In any simulator, once we got to composition of any feed stream tab, we can enter component mol/vol/wt fractions and if sum of all these component values does not equal to 1, then we can normalise the composition by pressing normalise button . i want to know how this normalisation is done. i know that it will distribute rest of the percent to all other fractions with provision that higher the preent of current component , it will get higher weightage .let me know on this.

[PaoloPemi]

in most cases you specify weight fractions or molar fractions,

to convert from mole fraction to weight fractions calculate average molar weight (for that mixture), then wf(1) = mf(1) * mw(1) / mwm  etc. 

yes you can enter volume fractions but these are simply converted to molar (or weight) fractions via ideal gas law at normal or standard T,P conditions, 

in general real volumes (calculated from a EOS or similar systems at specified operating consitions) are available (as enthalpies and other properties)  as output  (I attach a simple example showing the stream editor in Prode Properties, of course different simulators can show different information)

 stream.jpg   96.19KB   1 downloads

Edited by PaoloPemi, 29 June 2020 - 04:06 AM.