3 replies to this topic

[muddu4]

hello friends,

i need your help, i want to know whether there is any relation between uop characterization factor, enthalphy and temperature, any equation connecting all these 3 factors or any kind of graph........ please make me through my problem

[Zauberberg]

Watson factor is purely for hydrocarbon characterization purpose: it is a measure of petroleum fraction (or crude oil) paraffinicity, with high values corresponding to high degrees of saturation.

I am not sure if I understood your question. Kw is constant (for a given petroleum cut), and enthalpy is function of temperature. Once when you identify Kw of your stream - based on mean average boiling point and specific gravity - you should look for enthalpy vs. temperature curves, for which I remember they are available in API data book (but maybe I am wrong, it was a long time ago).

Or, you can use software to do this for you: based on Kw and standard density of hydrocarbon, HYSYS is able to generate hydrocarbon assay based on internal TBP curve (Whitson molar distribution model). However, the accuracy of this approach is not very high, but it can give you some feeling about relative enthalpies at various temperature levels.

Hope this helps,

Calculation of Enthalphy is complecated process, the below picture is extracted from Crude Oil (edited by Technip) book, there are also other methods but this is the simplest one.


Cheers

[srfish]

There is an article by Lee-Kesler that has charts of temperature vs enthalpy. It has Watson K factors of 10.0, 11.0, 11.8 and 12.5. There are also equations for Pc,Tc and acentric factor. These can be used to calculate the Lee-Kesler equation of state to calculate enthalpy. The article is in Hydrocarbon Processing March 1976