Try NeqSim in a clean Google Colab runtime. The setup cell installs the current PyPI release; the examples below then run without a local Java or Python setup.

One-Click Start

Click to open a ready-to-run notebook:

Open In Colab

Quick Setup Cell

If starting from a blank notebook, run this cell first:

# Install NeqSim (takes ~30 seconds)
!pip install neqsim -q

# Import NeqSim and report the installed version
from importlib.metadata import version
from neqsim import jneqsim

print(f"NeqSim {version('neqsim')} ready!")

Your First Calculation

from neqsim import jneqsim

# Create a natural gas at 25°C and 50 bar
fluid = jneqsim.thermo.system.SystemSrkEos(273.15 + 25, 50.0)
fluid.addComponent("methane", 0.85)
fluid.addComponent("ethane", 0.10)
fluid.addComponent("propane", 0.05)
fluid.setMixingRule("classic")

# Flash calculation
ops = jneqsim.thermodynamicoperations.ThermodynamicOperations(fluid)
ops.TPflash()
fluid.initProperties()

# Results
print(f"Phases: {fluid.getNumberOfPhases()}")
print(f"Density: {fluid.getDensity('kg/m3'):.2f} kg/m³")
print(f"Z-factor: {fluid.getZ():.4f}")

Example Notebooks

The repository notebooks below do not repeat the installation command. In a fresh Colab runtime, run the Quick Setup Cell above as the first cell before running their NeqSim imports.

Notebook Description Open
Introduction Getting started examples Open
Reading Properties Init levels, density, units Open
PVT Simulation Fluid characterization, tuning Open
Gathering Network Solver Multi-well pressure-flow allocation Open
ESP Pump Electric submersible pump Open

Quick Process Example

from neqsim import jneqsim

# Aliases for cleaner code
SystemSrkEos = jneqsim.thermo.system.SystemSrkEos
ProcessSystem = jneqsim.process.processmodel.ProcessSystem
Stream = jneqsim.process.equipment.stream.Stream
Separator = jneqsim.process.equipment.separator.Separator
Compressor = jneqsim.process.equipment.compressor.Compressor

# Create a two-phase feed at 30°C and 50 bara
fluid = SystemSrkEos(273.15 + 30, 50.0)
fluid.addComponent("methane", 0.70)
fluid.addComponent("ethane", 0.10)
fluid.addComponent("propane", 0.10)
fluid.addComponent("n-butane", 0.05)
fluid.addComponent("n-pentane", 0.05)
fluid.setMixingRule("classic")

# Build process
process = ProcessSystem()

feed = Stream("Feed", fluid)
feed.setFlowRate(10000.0, "kg/hr")
feed.setTemperature(30.0, "C")
feed.setPressure(50.0, "bara")
process.add(feed)

sep = Separator("Separator", feed)
process.add(sep)

comp = Compressor("Compressor", sep.getGasOutStream())
comp.setOutletPressure(100.0, "bara")
comp.setIsentropicEfficiency(0.75)
process.add(comp)

# Run
process.run()

# Results
print(f"Gas rate: {sep.getGasOutStream().getFlowRate('kg/hr'):.0f} kg/hr")
print(f"Liquid rate: {sep.getLiquidOutStream().getFlowRate('kg/hr'):.0f} kg/hr")
print(f"Compressor power: {comp.getPower('kW'):.1f} kW")

With NeqSim 3.16.0, this case gives approximately 7,588 kg/h gas, 2,412 kg/h liquid, and 202.2 kW compressor power. Small differences can occur between releases, but both separator products and the compressor power must be positive and the two product mass flows must close to the 10,000 kg/h feed.

Visualization in Colab

import matplotlib.pyplot as plt
import numpy as np
from neqsim import jneqsim

# Phase envelope calculation
fluid = jneqsim.thermo.system.SystemSrkEos(273.15 + 25, 50.0)
fluid.addComponent("methane", 0.80)
fluid.addComponent("ethane", 0.10)
fluid.addComponent("propane", 0.05)
fluid.addComponent("n-butane", 0.05)
fluid.setMixingRule("classic")

ops = jneqsim.thermodynamicoperations.ThermodynamicOperations(fluid)
ops.calcPTphaseEnvelope()

# Extract data
dew_temps = list(ops.get("dewT"))
dew_press = list(ops.get("dewP"))
bub_temps = list(ops.get("bubT"))
bub_press = list(ops.get("bubP"))

# Plot
plt.figure(figsize=(10, 6))
plt.plot(
    [temperature - 273.15 for temperature in dew_temps],
    dew_press,
    "b-",
    label="Dew line",
    linewidth=2,
)
plt.plot(
    [temperature - 273.15 for temperature in bub_temps],
    bub_press,
    "r-",
    label="Bubble line",
    linewidth=2,
)
plt.xlabel("Temperature (°C)")
plt.ylabel("Pressure (bara)")
plt.title("Phase envelope")
plt.legend()
plt.grid(True, alpha=0.3)
plt.show()

Tips for Colab

  1. Runtime disconnects: Colab may disconnect after idle time. Re-run the install cell if needed.

  2. Review warnings: Do not hide warnings from flashes or process equipment; they can indicate convergence or validity problems. To reduce only Python gateway logging, use:

    import logging

logging.getLogger("jpype").setLevel(logging.WARNING)

  3. Save results: Download results to your Google Drive:

    from google.colab import drive
drive.mount('/content/drive')
# Save files to /content/drive/MyDrive/

Next Steps