Viscosity of PropaneGas 1

[chem55]

Hi..!

I need to calculate viscosity of Propane gas at 10.21 atm pressure and 40C temp. I checked in Perry For prediction of the vapour viscosity of gaseous hydrocarbons but there are two equations and first one is for low pressure and second one is for high pressure.

Could you pls help me out which formula i can use?

regards,
chem55

 

[TD2K]

Gas viscosities are not strongly dependent on pressure except near the critical point and at reduced temperatures of 1 to 2 at high pressures based on "Properties of Gases and Liquids".

Pc is 618 psia and Tc is 205F for propane. For the temperature and pressure you give, I'd use the low pressure viscosity correlation.

 

[DickRussell]

I ran the quick calc through a process simulator (PD-PLUS); the viscosity is calculated with pressure correction, using the methods recommended by the API Technical Data Book and the DIPPR Data Prediction Manual. The viscosity of a low pressure gas is mostly temperature-dependent, but as pressure rises the effect is significant. This is what I got.

P (psia) Viscosity (cp)
15 0.00875
30 0.00879
50 0.00885
75 0.00892
100 0.00901
125 0.00911
150 0.00922 (this is your 10.21 atm)

Dick Russell

 

[Montemayor]

chem55 (Chemical)

Simply go to:

http://webbook.nist.gov/chemistry/fluid/

and find every thermodynamic property on Propane that you ever wanted. The viscosity can be given you in any of a variety of units: uPa*s, Pa*s, cP, or lbm/ft*s.

This is the official USA govenment site for the National Institute of Standards and Technology. It is the feeder for ASHRAE, universities, research centers, and many others - including tax-paying citizens. It is FREE thermodynamic data that is sanctioned because it is recognized, approved and has the blessing of the NIST. What else could you ask for?

I often download the data into spreadsheets for calculations and even regress the data into curves. It's easy and a fast way to handle the information.

This is such a frequently asked query (for a variety of compounds) that I think I'll write an FAQ on it.

Art Montemayor
Spring, TX

 

[chem55]

Hi TD2k & DickRussell: Thanks for your valuable suggestion..! I have calculated the viscosity which match with DickRussell value.

Dear Montemayor: The link which you have provided me is really extra ordinary. I think you are right, this is a valuable web site for all chemical engineers; you should write it on FAQ.

Do you know this kind of link for vapor pressure data?

Ronak