GPSA Method · Rachford-Rice · Wilson Correlation
Solves the Rachford-Rice equation iteratively:
β = vapor fraction (V/F), zi = feed composition
Understand flash calculations principles, calculations, and industry applications
Component Tc, Pc, and ω values from NIST Chemistry WebBook and DIPPR database, validated against GPSA Table 23-3.
| Wilson: | P < 500 psia, Tr < 0.9 |
| Raoult: | P < 100 psia, ideal mixtures |
| Components: | C₁ through nC₄ paraffins |
For higher pressures or near-critical conditions, use equation of state methods (SRK, PR).
| Comp | Tc (°R) | Pc (psia) | ω |
|---|---|---|---|
| C₁ | 343.0 | 667.8 | 0.012 |
| C₂ | 549.8 | 708.3 | 0.100 |
| C₃ | 665.7 | 617.4 | 0.152 |
| nC₄ | 765.3 | 551.1 | 0.200 |
Source: NIST/DIPPR, verified against GPSA Table 23-3