NeqSim Documentation

Industrial Agentic Engineering with NeqSim — AI Agents for Engineering Task Solving in Industry. NeqSim (Non-Equilibrium Simulator) is a comprehensive Java library developed at NTNU.

🚀 Get Started 🔎 Search Documentation ⭐ Star on GitHub 📖 Reference Manual Index 📘 JavaDoc API

📚 Core Documentation

Getting Started
Installation and first steps
Getting Started with Java
Install, first calculations, developer setup
Build & Run with Docker
Build the container; use NeqSim from Java and Python
Modules Overview
Architecture and package structure
Reference Manual Index
Topic index for guides, workflows, and examples

🔬 Thermodynamics

Thermo Package
Equations of state, mixing rules, fluids
Thermodynamic Operations
Flash calculations, phase envelopes
Physical Properties
Viscosity, conductivity, diffusivity
Experimental CO₂ Impurity Kinetic Reactor
Balanced trace-reaction network, reactor usage, safeguards, and limitations

🏭 Process Simulation

Process Equipment
Separators, compressors, heat exchangers
Fluid Mechanics
Pipeline flow, pressure drop
Safety Systems
Relief valves, flare systems

🏗️ Engineering

Engineering Hub
Design cases, discipline calculations, safety, and handover
Engineering Guide
From a converged process model to review-ready deliverables
Current Capabilities
Implemented APIs, discipline coverage, readiness, and boundaries
DEXPI Engineering Guide
Plant, Process, Proteus, pyDEXPI, validation, and qualification

📊 Applications

PVT Simulation
Reservoir fluid characterization
Black Oil Models
Simplified correlations
Field Development
Integrated workflows

⚠️ Risk & Reliability

Risk Simulation
Equipment failure, Monte Carlo analysis
SIS/SIF Integration
IEC 61508/61511, LOPA, SIL verification
Bow-Tie Analysis
Barrier analysis, threat visualization

🤖 AI-Assisted Engineering

Solve an Engineering Task
From problem statement to validated report — no coding required
Task Solving Guide
Multi-agent workflow with validation and report generation

🎯 Optimization & Cost

Production Optimization
Throughput, multi-objective, Pareto
Cost Estimation
CAPEX, OPEX, financial metrics
External Optimizers
Python/SciPy integration

🌱 Emissions & Sustainability

Emissions Hub
Landing page for all emission documentation
Offshore Reporting Guide
Regulatory framework, methods, validation
Emissions Tutorial
CO₂, methane, nmVOC from produced water

⚡ Quick Start Example

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import neqsim.thermo.system.SystemInterface;
import neqsim.thermo.system.SystemSrkEos;
import neqsim.thermodynamicoperations.ThermodynamicOperations;

public final class NeqSimQuickStart {
  private static final Logger logger = LogManager.getLogger(NeqSimQuickStart.class);

  private NeqSimQuickStart() {}

  public static void main(String[] args) {
    SystemInterface gas = new SystemSrkEos(298.15, 50.0);
    gas.addComponent("methane", 0.90);
    gas.addComponent("ethane", 0.05);
    gas.addComponent("propane", 0.03);
    gas.addComponent("CO2", 0.02);
    gas.setMixingRule("classic");

    ThermodynamicOperations operations = new ThermodynamicOperations(gas);
    operations.TPflash();
    gas.initProperties();

    logger.info("Density: {} kg/m3", gas.getDensity("kg/m3"));
    logger.info("Compressibility: {}", gas.getZ());
  }
}

🆕 Quickstart & Learning Resources

⚡ Quickstart Guides

Get running in 5 minutes!

📖 Cookbook

Copy-paste recipes for common tasks

🎓 Learning Paths

Structured tracks by role

🔧 Troubleshooting

Solutions to common problems

📖 Documentation Sections

Section	Description
🧪 Thermodynamics	Equations of state, phase behavior, component properties
⚙️ Process Simulation	Unit operations, process systems, controllers
🏗️ Engineering	Design cases, equipment sizing, safety verification, deliverables, and lifecycle evidence
🔄 Dynamic Simulation	Transient simulation, time-stepping, depressurization
📊 Physical Properties	Transport properties, interfacial tension
🛢️ PVT Simulation	Reservoir fluid characterization, tuning
🌊 Fluid Mechanics	Pipeline flow, multiphase modeling
🎯 Optimization	Production optimization, multi-objective, constraints
⚠️ Risk & Reliability	Equipment failure, Monte Carlo, SIS/SIF, bow-tie
🛡️ Safety Systems	ESD, HIPPS, PSV, blowdown, alarms
🌱 Emissions & Sustainability	CO₂, methane, nmVOC virtual measurement, Norwegian methods
💰 Cost Estimation	CAPEX, OPEX, financial metrics (NPV, ROI)
💡 Examples	Tutorials, Jupyter notebooks, code samples
🤖 AI-Assisted Engineering	Multi-agent task solver: simulation, validation, and report generation
🔧 Development	Contributing guidelines, developer setup

📚 Reference Manual Index

The Reference Manual Index organizes the documentation collection by topic and links to current guides, examples, and package references:

✅ Topic-based navigation

✅ Setup, thermodynamics, process, and engineering guides

✅ Usage guides and verified examples

✅ Cross-referenced documentation

🐍 Python Integration

NeqSim is also available for Python through neqsim-python:

from neqsim import jneqsim

# Create and flash a natural gas
gas = jneqsim.thermo.system.SystemSrkEos(298.15, 50.0)
gas.addComponent("methane", 0.9)
gas.addComponent("ethane", 0.1)
gas.setMixingRule("classic")

operations = jneqsim.thermodynamicoperations.ThermodynamicOperations(gas)
operations.TPflash()
gas.initProperties()
print(f"Gas density: {gas.getDensity('kg/m3'):.2f} kg/m³")

🔗 Resources

📦 GitHub Repository
Source code & issues ☕ Maven Central
Latest releases 🐛 Issue Tracker
Report bugs 💬 Discussions
Community Q&A