1. What is K-Value in Gamma-Phi Formulation?

Definition: The K-value is defined as the ratio of vapor-phase mole fraction to the liquid-phase mole fraction of a component in a mixture.

Purpose: It's a crucial parameter in vapor-liquid equilibrium calculations for distillation and separation processes.

2. How Does the Calculator Work?

The calculator uses the Gamma-Phi formulation formula:

Where:

• \( K \) — K-value (dimensionless)
• \( \gamma_{Raoults} \) — Activity coefficient in Raoult's law
• \( P^{sat} \) — Saturated pressure (Pa)
• \( \phi_{Raoults} \) — Fugacity coefficient in Raoult's law
• \( P_T \) — Total system pressure (Pa)

Explanation: The formula accounts for non-ideal behavior in both liquid (via activity coefficient) and vapor (via fugacity coefficient) phases.

3. Importance of K-Value Calculation

Details: Accurate K-values are essential for designing distillation columns, flash drums, and other separation equipment in chemical processes.

4. Using the Calculator

Tips: Enter all required parameters - activity coefficient, saturated pressure, fugacity coefficient, and total pressure. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does a K-value greater than 1 mean?
A: A K-value > 1 indicates the component is more concentrated in the vapor phase than in the liquid phase.

Q2: What's a typical range for activity coefficients?
A: Activity coefficients typically range from 0.5 to 2.0 for most systems, though extreme values are possible.

Q3: When would the fugacity coefficient differ significantly from 1?
A: At high pressures or for polar/non-ideal gases, fugacity coefficients can deviate substantially from 1.

Q4: How does temperature affect K-values?
A: Temperature primarily affects the saturated pressure (P^sat) term, with higher temperatures generally increasing K-values.

Q5: What's the ideal case for this formula?
A: For ideal systems, both γ and φ become 1, simplifying to Raoult's Law: K = P^sat/P_T.