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Definition: This calculator computes the reduced pressure using the Peng-Robinson equation of state, given reduced and critical parameters.
Purpose: It helps in thermodynamic calculations for real gases, particularly in petroleum and chemical engineering applications.
The calculator uses the Peng-Robinson equation:
Where:
Details: Reduced properties are crucial for corresponding states theory and help predict thermodynamic behavior of real gases.
Tips: Enter all required parameters. Ensure all values are positive. Critical parameters are substance-specific.
Q1: What are typical values for Peng-Robinson parameters?
A: These vary by substance. For example, for water: a ≈ 0.4572 Pa·m⁶/mol², b ≈ 1.49×10⁻⁵ m³/mol.
Q2: How do I obtain critical parameters?
A: Critical parameters are tabulated for most substances in thermodynamic databases.
Q3: What is the α-function?
A: It's a temperature-dependent function that accounts for deviations from ideal behavior.
Q4: Can this be used for all gases?
A: The Peng-Robinson equation works well for non-polar and slightly polar compounds.
Q5: Why use reduced properties?
A: They allow generalized correlations that work for many substances.