Fugacity Formula:
From: | To: |
Definition: Fugacity is a thermodynamic property that effectively represents the "escaping tendency" of a component from a phase. For liquid phase species, it's calculated using the Poynting factor correlation.
Purpose: This calculation is essential in chemical engineering for phase equilibrium calculations, particularly in distillation, absorption, and other separation processes.
The calculator uses the formula:
Where:
Explanation: The formula accounts for deviations from ideal gas behavior through the fugacity coefficient and pressure effects through the Poynting factor (exponential term).
Details: Accurate fugacity calculations are crucial for predicting phase equilibria in chemical processes, designing separation systems, and modeling non-ideal fluid behavior.
Tips: Enter all required parameters with consistent units. Default values are provided for demonstration. Temperature must be in Kelvin, pressures in Pascals, and volume in cubic meters.
Q1: What is the physical meaning of fugacity?
A: Fugacity represents the effective pressure of a real gas or liquid that would give the same behavior as an ideal gas at the same conditions.
Q2: When is the Poynting correction significant?
A: The Poynting factor becomes important when system pressure differs significantly from the saturation pressure.
Q3: What's a typical range for φsat?
A: For many substances near their normal boiling point, φsat ranges from 0.9 to 1.1, but can vary more widely at extreme conditions.
Q4: How do I find Vl for my substance?
A: Liquid molar volumes can be found in chemical engineering handbooks or estimated from density data.
Q5: Can this be used for mixtures?
A: This calculates pure component fugacity. For mixtures, activity coefficients would also be needed.