K-Value Formula:
From: | To: |
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.
The calculator uses the Gamma-Phi formulation formula:
Where:
Explanation: The formula accounts for non-ideal behavior in both liquid (via activity coefficient) and vapor (via fugacity coefficient) phases.
Details: Accurate K-values are essential for designing distillation columns, flash drums, and other separation equipment in chemical processes.
Tips: Enter all required parameters - activity coefficient, saturated pressure, fugacity coefficient, and total pressure. All values must be > 0.
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 (Psat) 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 = Psat/PT.