Generalized products density correction algorythms??
Generalized products density correction algorythms??
(OP)
Hi!!
I am looking for an algorythm which corrects the density of petroleum products from physical temperature to 15oC.
I have heard that such thing is written in ASTM petroleum measurement tables volume X which I do not have.
I want to automate a process by entering in an excel file the volume and density of petroleum,without looking each time to the correction tables (ASTM tables53b-54b) in order to calculate the real volume in 15oC??
Any help would be appreciated!!
Thank you!!
I am looking for an algorythm which corrects the density of petroleum products from physical temperature to 15oC.
I have heard that such thing is written in ASTM petroleum measurement tables volume X which I do not have.
I want to automate a process by entering in an excel file the volume and density of petroleum,without looking each time to the correction tables (ASTM tables53b-54b) in order to calculate the real volume in 15oC??
Any help would be appreciated!!
Thank you!!





RE: Generalized products density correction algorythms??
RE: Generalized products density correction algorythms??
In general, paraffinic hydrocarbons have comparatively low densities, naphthenic and olefinic hydrocarbons intermediate densities, and aromatic hydrocarbons comparatively high densities.
Pure hydrocarbons happen to also have differing coefficients of cubic thermal expansion at the same temperature.
For example, at 25 deg C: benzene, 1.14; paraxylene, 1.0; pentane, 1.64; hexane, 1.41; cyclohexane, 1.15; heptane, 1.26; octane, 1.16; nonane, 1.08 x 10-3/oC.
For the paraffins it continues in dropping down with increasing molecular masses, as follows: C10, 1.02; C11, 0.97; C12, 0.93; C13, 0.90; C14, 0.87. Compare with water: 0.256 x 10-3/oC.
The coefficient increases with temperature in a different manner, for example, toluene at 20oC, 1.05, and at 50oC, 1.13x10-3/oC; hexane at 25oC, 1.41, whilst at 45oC its coefficient rises to 1.52x10-3/oC.
For these light hydrocarbons as well as for mixtures under pressure of propane and butane, see PERRY VI Chapter 3.
RE: Generalized products density correction algorythms??
There is also a factor called the viscosity gravity constant (VGC) that will help identify if a hydrocarbon is parrafinic or kerosene based (as i recall).
See ASTM D2501-91(2000) where there is also an equation for this.
RE: Generalized products density correction algorythms??
This file helped allot!!
Right now I've managed to combine the use of table 53B and 54B in an excel ,so when entering:
-real volume & temperature of fluid in tank
-observed density and observed temperature in hydrometer cylinder
I have the volume in 15 degrees C.
The only problem is when dealing with floating roofs , where I need to exclude from the total volume, the volume that occupies the roof;
which comes by dividing (the actual weight of the roof) by (the corrected density to the tank temperature).
How should I convert the observed density in the hydrometer , to density of fluid in the tank ????
Thank you all again for your precious time!!!
RE: Generalized products density correction algorythms??
RE: Generalized products density correction algorythms??
Actual volumes should consider the tank volume changes in L/mm at temperatures differing from 15 deg C, a temperature normally used for reference in calibration.
When dealing with heavy fuels, sometimes even with crude oils, sampling for density measurements should be "representative" of the tank contents, otherwise errors due to "layering" may occur. Often, samples are taken at different (top, middle, bottom) elevations to that end.
RE: Generalized products density correction algorythms??
RE: Generalized products density correction algorythms??
I then fitted a polynomial to the slopes and now have a method of calculating density at any temperature for temps upto 400C and densities at 15C ranging from 900 to 1100kg/m^3, which seems good enough for fuel oils.
athomas236
RE: Generalized products density correction algorythms??
http://www.viscoanalyser.com/downloads.html
JMW
www.viscoanalyser.com
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RE: Generalized products density correction algorythms??
but thanks for your help anyway guys...
I am after Table 54B Genral products correction of volume to 15'C against density at 15'C.
I wish to convert measured litres in our storage tanks to standard (at 15'C) liters.