1. Vapor Fugacity
Pure Systems

2. Recap Fugacity is our new definition for equilibrium
With IG as a reference state
Fugacity coefficient defines relationship to IG state

3. Consider a pure system Your book uses: IG P (P=0) as reference state
Low P as ref state
BUT
This notation ONLY good for tabulated data

4. Vapor Fugacity From Steam Tables
How do I get g from a steam table?
In this notation, how would I get the reference g?

5. Vapor Fugacity for Steam Table Example
Determine the fugacity and fugacity coefficient for Steam at 200oC and 10 bar

6. Vapor Fugacity for Steam Table Example- Step 1
Look up h and s at the stated T and P

7. Vapor Fugacity for Steam Table Example- Step 2
Look up h and s at the stated T and P
Look up h and s at the stated T and the lowest P you can find (P=10 kPa)

8. Vapor Fugacity for Steam Table Example- Step 3
Look up h and s at the stated T and P
Look up h and s at the ref state
Calculate g and ref g

9. Vapor Fugacity for Steam Table Example- Step 4
Look up h and s at the stated T and P
Look up h and s at the ref state
Calculate g and ref g
Plug and/or chug

10. Pure Vapor Fugacity from Correlation Tables
When considering compressiblity (Z) gases correlate relative to their critical point
Tr=T/Tc
Pr=P/Pc

11. Pure Vapor Fugacity from Generalized Correlations
Find the fugacity and fugacity coefficient of water using generalized correlations at 212oC and 10 bar
Pc= bar
Tc=647.3 K
w=0.344

12. Pure Vapor Fugacity from Generalized Correlations - 2
Look up values
Done
Calculate reduced P and T

13. Pure Vapor Fugacity from Generalized Correlations - 3
Look up values
Calculate reduced P and T
Look up in table, interpolate if need be

14. Pure Vapor Fugacity from Generalized Correlations - 4
Look up values
Done
Calculate reduced P and T
Look up in table, interpolate if need be
Plug and chug

15. What about mixtures? No tables exist for mixtures EOS (later) –OR-
Generalized Correlation tables

16. Summary Vapor fugacity of pure steam Find h and s at state
Find h and s at ref state (10 kPa and same T)
Calculate g and ref g
Plug and chug
Formula is NOT for phi (multiply by low P not system P for f
Divide f by system P for phi

17. Summary Fugacity from correlation tables (pure and mixed)
Find or calculate critical info
Find reduced P and T
Look up values in tables (may need to interpolate)
Plug and chug
Reminder: log not ln in Koretsky tables