"""Rachford-Rice flash calculation example.
This example demonstrates vapor-liquid equilibrium calculations
using the Rachford-Rice equation for phase behavior analysis.
"""
import asyncio
from fastmcp.client import Client
from pyrestoolbox_mcp import mcp
async def rachford_rice_example():
"""Rachford-Rice flash calculation examples."""
# Client context
async with Client(mcp) as client:
print("=" * 80)
print("Rachford-Rice Flash Calculation Examples")
print("=" * 80)
# Example 1: Simple binary system
print("\nExample 1: Binary System (Methane + Propane)")
print("-" * 80)
flash1 = await client.call_tool(
"rachford_rice_flash",
{
"zis": [0.6, 0.4], # Overall composition: 60% C1, 40% C3
"Kis": [3.0, 0.3], # K-values at P, T
},
)
print(f"Overall Composition: C1={0.6:.1%}, C3={0.4:.1%}")
print(f"K-values: K_C1={3.0:.2f}, K_C3={0.3:.2f}")
print(f"\nResults:")
print(f" Vapor Fraction (β): {flash1['vapor_fraction']:.4f}")
print(f" Liquid Fraction: {1 - flash1['vapor_fraction']:.4f}")
print(f"\n Liquid Composition:")
for i, xi in enumerate(flash1["liquid_composition"]):
comp = "C1" if i == 0 else "C3"
print(f" {comp}: {xi:.4f}")
print(f"\n Vapor Composition:")
for i, yi in enumerate(flash1["vapor_composition"]):
comp = "C1" if i == 0 else "C3"
print(f" {comp}: {yi:.4f}")
# Example 2: Three-component system
print("\nExample 2: Three-Component System")
print("-" * 80)
flash2 = await client.call_tool(
"rachford_rice_flash",
{
"zis": [0.5, 0.3, 0.2], # C1, C2, C3
"Kis": [2.5, 1.2, 0.4],
},
)
components = ["C1", "C2", "C3"]
print(f"Overall Composition: {', '.join([f'{c}={z:.1%}' for c, z in zip(components, [0.5, 0.3, 0.2])])}")
print(f"K-values: {', '.join([f'K_{c}={k:.2f}' for c, k in zip(components, [2.5, 1.2, 0.4])])}")
print(f"\nResults:")
print(f" Vapor Fraction: {flash2['vapor_fraction']:.4f}")
print(f"\n Liquid Composition:")
for comp, xi in zip(components, flash2["liquid_composition"]):
print(f" {comp}: {xi:.4f}")
print(f"\n Vapor Composition:")
for comp, yi in zip(components, flash2["vapor_composition"]):
print(f" {comp}: {yi:.4f}")
# Example 3: Near-critical conditions
print("\nExample 3: Near-Critical Conditions")
print("-" * 80)
flash3 = await client.call_tool(
"rachford_rice_flash",
{
"zis": [0.7, 0.2, 0.1], # High C1 content
"Kis": [1.1, 0.9, 0.8], # K-values near 1.0
},
)
print(f"Overall Composition: C1=70%, C2=20%, C3=10%")
print(f"K-values: K_C1=1.1, K_C2=0.9, K_C3=0.8 (near critical)")
print(f"\nResults:")
print(f" Vapor Fraction: {flash3['vapor_fraction']:.4f}")
print(f" Note: Near-critical conditions result in small phase split")
# Example 4: Separator flash calculation
print("\nExample 4: Separator Flash Calculation")
print("-" * 80)
# Typical separator conditions: 100 psia, 80 degF
# K-values would be calculated from EOS or correlations
separator_flash = await client.call_tool(
"rachford_rice_flash",
{
"zis": [0.65, 0.20, 0.10, 0.05], # C1, C2, C3, nC4
"Kis": [8.5, 2.2, 0.6, 0.15], # K-values at separator conditions
},
)
sep_components = ["C1", "C2", "C3", "nC4"]
print(f"Feed to Separator:")
print(f" Composition: {', '.join([f'{c}={z:.1%}' for c, z in zip(sep_components, [0.65, 0.20, 0.10, 0.05])])}")
print(f"\nSeparator Conditions: 100 psia, 80 degF")
print(f"K-values: {', '.join([f'K_{c}={k:.2f}' for c, k in zip(sep_components, [8.5, 2.2, 0.6, 0.15])])}")
print(f"\nResults:")
print(f" Vapor Fraction (Gas): {separator_flash['vapor_fraction']:.4f}")
print(f" Liquid Fraction (Oil): {1 - separator_flash['vapor_fraction']:.4f}")
print(f"\n Separator Gas Composition:")
for comp, yi in zip(sep_components, separator_flash["vapor_composition"]):
print(f" {comp}: {yi:.4f} ({yi*100:.2f}%)")
print(f"\n Separator Oil Composition:")
for comp, xi in zip(sep_components, separator_flash["liquid_composition"]):
print(f" {comp}: {xi:.4f} ({xi*100:.2f}%)")
# Example 5: Sensitivity to K-values
print("\nExample 5: Sensitivity to K-Values")
print("-" * 80)
z_feed = [0.6, 0.4]
k_scenarios = [
[2.0, 0.5],
[3.0, 0.3],
[4.0, 0.2],
[5.0, 0.15],
]
print(f"Feed Composition: C1=60%, C3=40%")
print(f"\n{'K_C1':>8} | {'K_C3':>8} | {'Vapor Frac':>12} | {'y_C1':>10} | {'x_C1':>10}")
print("-" * 55)
for k_vals in k_scenarios:
flash_sens = await client.call_tool(
"rachford_rice_flash",
{
"zis": z_feed,
"Kis": k_vals,
},
)
y_c1 = flash_sens["vapor_composition"][0]
x_c1 = flash_sens["liquid_composition"][0]
print(
f"{k_vals[0]:8.2f} | {k_vals[1]:8.2f} | {flash_sens['vapor_fraction']:12.4f} | "
f"{y_c1:10.4f} | {x_c1:10.4f}"
)
print("\n" + "=" * 80)
print("Rachford-Rice Flash Examples completed successfully!")
print("=" * 80)
if __name__ == "__main__":
asyncio.run(rachford_rice_example())
