PR_WATER_K_VALUE

This function estimates a component equilibrium ratio against water using the Peng-Robinson water heuristic.

It applies:

K_i = 10^6\frac{P_{r,i}}{T_{r,i}}

where reduced properties are formed from system and critical conditions.

Excel Usage

=PR_WATER_K_VALUE(temperature, pressure, critical_temperature, critical_pressure)

temperature (float, required): System temperature (K).
pressure (float, required): System pressure (Pa).
critical_temperature (float, required): Component critical temperature (K).
critical_pressure (float, required): Component critical pressure (Pa).

Returns (float): Estimated hydrocarbon-water equilibrium K-value.

Example 1: Octane-like case near ambient pressure

Inputs:

temperature	pressure	critical_temperature	critical_pressure
300	100000	568.7	2490000

Excel formula:

=PR_WATER_K_VALUE(300, 100000, 568.7, 2490000)

Expected output:

76131.2

Example 2: Elevated pressure case

Inputs:

temperature	pressure	critical_temperature	critical_pressure
320	500000	568.7	2490000

Excel formula:

=PR_WATER_K_VALUE(320, 500000, 568.7, 2490000)

Expected output:

356865

Example 3: Light hydrocarbon-like case

Inputs:

temperature	pressure	critical_temperature	critical_pressure
280	1000000	305.3	4880000

Excel formula:

=PR_WATER_K_VALUE(280, 1000000, 305.3, 4880000)

Expected output:

223434

Example 4: Warmer process condition

Inputs:

temperature	pressure	critical_temperature	critical_pressure
360	200000	540.2	2736000

Excel formula:

=PR_WATER_K_VALUE(360, 200000, 540.2, 2736000)

Expected output:

109690

Python Code

Show Code

from chemicals.flash_basic import PR_water_K_value as chemicals_pr_water_k_value

def pr_water_k_value(temperature, pressure, critical_temperature, critical_pressure):
    """
    Estimate hydrocarbon-water equilibrium K-value with the Peng-Robinson heuristic.

    See: https://chemicals.readthedocs.io/chemicals.flash_basic.html#chemicals.flash_basic.PR_water_K_value

    This example function is provided as-is without any representation of accuracy.

    Args:
        temperature (float): System temperature (K).
        pressure (float): System pressure (Pa).
        critical_temperature (float): Component critical temperature (K).
        critical_pressure (float): Component critical pressure (Pa).

    Returns:
        float: Estimated hydrocarbon-water equilibrium K-value.
    """
    try:
        return chemicals_pr_water_k_value(temperature, pressure, critical_temperature, critical_pressure)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

temperature *

System temperature (K).

pressure *

System pressure (Pa).

critical_temperature *

Component critical temperature (K).

critical_pressure *

Component critical pressure (Pa).