Vapor-Liquid Equilibrium

VLE calculations determine phase splits and compositions.

K-Value Calculation

Using Raoult's Law:

Ki = Psat_i(T) / P

Vapor Pressure (Antoine)

log₁₀(Psat) = A - B/(T + C)

export function getVaporPressure(componentId: string, T_K: number): number {
  const comp = componentData[componentId];
  if (!comp?.antoine) return 0;
  
  const [A, B, C] = comp.antoine;
  const T_C = T_K - 273.15;
  const P_mmHg = Math.pow(10, A - B / (T_C + C));
  return P_mmHg * 133.322; // Pa
}

Flash Calculation

Rachford-Rice equation:

Σ zi(Ki - 1) / (1 + V(Ki - 1)) = 0

Limitations

• Ideal liquid solution (γ = 1)
• Ideal gas phase (φ = 1)
• No azeotrope prediction