software or tables of thermal properties for natural gas 2

[mickeymouse]

I am in need of thermal properties of natural gas at varying temperatures. They have given the specific gravity of .6, but I would like some direction on where to find software or tables.

Thanks for your help

 

[j2bprometheus]

mickey-

Do you want the properties at one temperature or many temperatures?

Do you want values for various compositions or just one composition? Natural gas composition varies.

Finding data like specific heat capacity for most components of natural gas is easy ( I just looked in a thermodynamics book and curve fits are available for each component). You then use the mole fractions of the components to find the specific heat capacity of the mixture. Lower heating value is done in a similar manner. I use a spreadsheet to do this.

There is an on-line calculator for pure substances at

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

AVL sells software that will calculate many properties of a given natural gas, if you provide the components of the natural gas. The software is called METHANE and it costs about $3,000. This is good for varying compositions but not good for varying temperatures.

 

[mbeychok]

Mickey:

How accurate do you need to be? Almost all natural gases are at least 90 volume percent methane. If you don't need any extreme accuracy, you could just use the thermal properties of methane.

As pointed out by j2bprometheus, the NIST website has a calculator where you can obtain the isobaric data by specifying a pressure (say 14.7 psia) and a temperature range (say 50 deg F to 200 deg F) in given increments (say 5 deg F), and obtain a table in HTML format of the gas density, specific heats (Cp and Cv), enthalpy, entropy, and thermal conductivity at each of those temperatures.



Milton Beychok
(Contact me at www.air-dispersion.com)

 

[LeSabre]

I think this link has every thing you need. Download ALLPROPS for Windows (v1.0).

http://www.webpages.uidaho.edu/~cats/software.htm

 

[gunnarhole]

I use an Excel addin to calculate gas mixure properties. It cost ~$200 and it is based on the Lee Kessler Equation of State. You probably wouldn't want to design an LNG facility with it but it is very handy for doing routine calculations. You can get it from Moongate Software.

Regards,

Gunnar

 

[j2bprometheus]

Hi-

An on-line calculator for heat of combustion of a natural gas type fuels is available at

http://www.processassociates.com/process/property/hc_gas.htm

j2bprometheus@aol.com