4 replies to this topic

[mbeychok]

Chrisp:

Page D-212 of the "Handbook of Chemistry and Physics" (56th Edition) has a tabulation of hydrogen vapor pressures that covers the temperature range of 13.8 °K to 32.98 °K which corresponds to a vapor pressure range of 0.069 atmospheres to 12.76 atmospheres.

If that is the range you are interested in, then you could use linear regression of that data to obtain a set of Antoine constants.

[MrShorty]

Any reason you need Antoine constants versus other vapor pressure equation parameters? It's generally accepted that the Antoine equation isn't suitable above ~2 atm, where the above referenced data set extends to ~13 atmospheres. An Antoine correlation would be limited to the data between the melting point and 2 atm (a range of ~10 K), where a more robust equation could get you from the melting point to the critical point (~20 K span). It depends on what temperature range you need the vapor pressure for.

[gvdlans]

Antoine Vapor Pressure Equation: ln(Pvap) = A-B/(T+C)
Pvap is vapor pressure in mmHg, T is temperature in Kelvin
A=13.633
B=164.90
C=3.19

Valid between T= 14 K and T=25 K

Taken from Coulson and Richardson's Chemical Engineering, Volume 6, 2nd edition, Appendix D.

Same parameters can be found in the Fysical Properties Spreadsheet that can be downloaded from http://www.cheresources.com/data.xls

It should not have been "extremely difficult" to find this?