Calculate gas deviation from ideal behavior with precision
Featured: Dranchuk-Abu-Kassem, Benedict-Webb-Rubin, Peng-Robinson
The Dranchuk-Abu-Kassem correlation is an analytical representation of the Standing-Katz Z-factor chart. It provides an accurate method for calculating the compressibility factor of natural gases based on reduced temperature and pressure.
Z = 1 + (A1 + A2/Tr + A3/Tr³)ρr + (A4 + A5/Tr)ρr² + A5A6ρr⁵/Tr + A7ρr²/Tr³(1 + A8ρr²)exp(-A8ρr²)
The BWR equation is an 8-parameter equation of state capable of representing both gas and liquid phases. It's particularly accurate for hydrocarbon systems and can predict vapor-liquid equilibria.
P = RTρ + (B0RT - A0 - C0/T²)ρ² + (bRT - a)ρ³ + aαρ⁶ + (cρ³/T²)(1 + γρ²)exp(-γρ²)
The Peng-Robinson EOS is a cubic equation of state widely used in chemical and petroleum engineering. It improves upon the Redlich-Kwong equation by providing better liquid density predictions.
P = RT/(V - b) - aα/[V(V + b) + b(V - b)]
where:
a = 0.45724 R²Tc²/Pc
b = 0.07780 RTc/Pc
α = [1 + κ(1 - √Tr)]²
κ = 0.37464 + 1.54226ω - 0.26992ω²
