Process Simulation Package

The process package provides process equipment, unit operations, controllers, and process system management for building complete flowsheets.

For controlled design cases, equipment and discipline sizing, safety verification, engineering deliverables, and handover, use the separate Engineering documentation.

Table of Contents

Overview

Location: neqsim.process

Purpose:

Documentation Structure

This documentation is organized into the following sections:

Section Description
equipment/ Equipment documentation (separators, compressors, etc.)
equipment/adsorption_bed.md Adsorption bed — transient simulation, LDF mass transfer, PSA/TSA cycles
lng_liquefaction.md LNG liquefaction — closed-loop SMR, C3MR, DMR, and nitrogen-expander templates with common KPIs and literature screening
mercury_removal.md Mercury removal guard beds — chemisorption (PuraSpec), bed loading, breakthrough, degradation, mechanical design, cost
bioprocessing.md Bio-processing — reactors, fermenters, solid-liquid separators, LLE, evaporators, dryers, crystallizers
neqsim-studio.md NeqSim Studio (Python) — newcomer-friendly process builder: natural language, templates, guided wizard, edit-by-chat, recipe gallery
processmodel/ ProcessSystem and flowsheet management
process_json_export_and_e300_fluids.md Process JSON export — self-contained ProcessSystem/ProcessModel JSON for MCP, including E300-equivalent component properties and volume correction
simulation-hooks-and-events.md Lifecycle hooks, event bus, auto-validation for ProcessSystem and ProcessModel
model-change-events.md Governed model revisions — versioned change events, idempotent publication, fingerprints, and durable replay
model-impact-analysis.md Cross-model impact analysis — configurable propagation rules, recalculation order, cycle detection, and reapproval work
safety/ Safety systems (PSV, ESD, blowdown)
controllers.md Process controllers and logic
unisim-to-neqsim-conversion.md UniSim/HYSYS conversion — convert .usc models to NeqSim with E300 full-fluid transfer and export back to UniSim
piping_route_builder.md STID/E3D line-list piping route builder — convert route tables into serial Beggs-and-Brill hydraulic models and water-hammer screening handoffs
water_hammer_implementation.md Water hammer/liquid hammer screening — fast valve closure, pump trip, STID route, tagreader event, and MCP runWaterHammer workflow
operational_evidence_package.md Operational evidence package — combine P&ID/STID references, tagreader values, scenario actions, and bottleneck detection
exergy-analysis.md Exergy analysis — plant-wide destruction hotspots for ProcessSystem and ProcessModel
production-allocation.md Production allocation — back-allocate metered production to wells/sources via a linear recovery-factor proxy network (handles recycle/reflux)
k-value-fast-simulation.md Cached K-value fast simulation — run one rigorous base-case process, freeze separator K-values and fallback splits, then execute fast source-rate scenarios without repeated EOS flashes
screening_calculators.md Screening and sizing calculators — flare radiation (API 521), line sizing/erosion LOF (API RP 14E), flow-induced vibration (AVIFF), pump NPSH, control-valve sizing/noise (IEC 60534), thermowell strength (ASME PTC 19.3), pipeline overpressure protection, orifice metering (GPSA), and crude desalting; with optional process-object bridges

Process Design Guide

Document Description
process_design_guide.md Complete guide to process design workflow using NeqSim

Design Framework (NEW) ✨

Document Description
DESIGN_FRAMEWORK.md Automated equipment sizing and optimization framework

Key Features:

Optimization and Constraints Framework (NEW) ✨

Document Description
optimization/OPTIMIZATION_AND_CONSTRAINTS.md COMPREHENSIVE: Complete guide to optimization algorithms, constraint types, bottleneck analysis
optimization/OPTIMIZATION_OVERVIEW.md When to use which optimizer
optimization/process-researcher.md Process researcher - generate and rank candidate flowsheets from feed/product targets, including reaction routes
CAPACITY_CONSTRAINT_FRAMEWORK.md Equipment capacity limits and utilization tracking

Key Features:

Corrosion Analysis ✨

Document Description
corrosion/ Corrosion analysis module overview — NORSOK M-506 CO2 corrosion rate + NORSOK M-001 material selection
corrosion/norsok_m506_corrosion_rate.md NORSOK M-506 API — CO2 corrosion rate prediction with fugacity, pH, correction factors
corrosion/norsok_m001_material_selection.md NORSOK M-001 API — Material grade recommendation, sour service, chloride SCC
corrosion/pipeline_corrosion_integration.md Pipeline integration — Automated corrosion analysis from process simulation

Electrical Design Documentation

Document Description
electrical-design.md Electrical design framework — motor sizing, VFD, cable, transformer, switchgear, hazardous area, equipment-specific designs, plant-wide load analysis

Dynamic Simulation

Document Description
dynamic-simulation.md Dynamic simulation helper — auto-instruments a sized steady-state process with transmitters and PID controllers for transient simulation

Key Features:

Instrument Design Documentation

Document Description
instrument-design.md Instrument design framework — ISA-5.1 identification, SIL-rated safety instruments, I/O counting, DCS/SIS cabinet sizing, cost estimation, equipment-specific designs (separator, compressor, heat exchanger, pipeline, valve), plant-wide SystemInstrumentDesign

Key Features:

Mechanical Design Documentation

Document Description
EQUIPMENT_DESIGN_PARAMETERS.md Equipment design parameters, autoSize vs MechanicalDesign guide
mechanical_design_standards.md Design standards (NORSOK, ASME, API, DNV, etc.)
standard_design_kernel_migration.md Migrate global editions, metadata factories, mutable calculators, and legacy case execution to typed kernels
mechanical_design_database.md Data sources, database schemas, and CSV configuration
pipeline_mechanical_design.md Pipeline mechanical design (wall thickness, stress, buckling, corrosion)
topside_piping_design.md Topside piping design (velocity, support, vibration per ASME B31.3)
riser_mechanical_design.md Riser design (catenary, VIV, fatigue per DNV-OS-F201)
well_mechanical_design.md Well casing/tubing design, barrier verification, cost estimation per NORSOK D-010, API 5CT
torg_integration.md Technical Requirements Documents (TORG) integration
field_development_orchestration.md Complete design workflow orchestration
mechanical_design/two_phase_heat_transfer.md Two-phase heat transfer — Shah condensation, Chen/Gungor-Winterton boiling, Friedel/MSH pressure drop, Ebert-Panchal fouling, incremental zone analysis, tube inserts

Cost Estimation Framework (NEW) ✨

Document Description
COST_ESTIMATION_FRAMEWORK.md Comprehensive capital and operating cost estimation, including scope-safe result reconciliation
COST_ESTIMATION_API_REFERENCE.md Detailed API reference for cost estimation classes and CostEstimateResult output maps

Key Features:

Equipment Categories

Category Documentation Classes
Streams streams.md Stream, EnergyStream, VirtualStream
Separators separators.md Separator, ThreePhaseSeparator, GasScrubber
Heat Exchangers heat_exchangers.md Heater, Cooler, HeatExchanger
Compressors compressors.md Compressor, CompressorChart, CompressorWashing
Compressor Deposit / Degradation compressor_deposit_degradation.md CompressorDeposit, DepositMechanism, DepositSource, CompressorDepositProfile, WashFluid, CompressorDepositWash
Compressor Anti-Surge Control compressor_antisurge_control.md AntiSurgeController, CompressorMonitor, ThrottlingValve, Recycle
Pumps pumps.md Pump, PumpChart
Expanders expanders.md Expander, TurboExpanderCompressor
Valves valves.md ThrottlingValve, SafetyValve, BlowdownValve
Choke Collapse Analysis choke-collapse.md ChokeCollapseAnalyzer — critical pressure ratio, flashing, cavitation
Inadvertent Valve Operation inadvertent-valve-operation.md InadvertentValveOperationAnalyzer — API 521 §4.4.13 / NORSOK P-002 IVO screening
Well Chokes well_choke_implementation.md Sachdeva, Gilbert choke models, ThrottlingValve integration
Distillation distillation.md DistillationColumn, SimpleTray
Absorbers absorbers.md SimpleAbsorber, SimpleTEGAbsorber
Ejectors ejectors.md Ejector
Membranes membranes.md MembraneSeparator
Flares flares.md Flare, FlareStack
Electrolyzers electrolyzers.md Electrolyzer, CO2Electrolyzer
Filters filters.md Particle, coalescing, strainer, and media filters with dynamic loading and mechanical design
H2S Scavengers H2S_scavenger_guide.md H2S chemical scavenging (triazine, glyoxal, iron sponge)
Sulfur Recovery sulfur_recovery.md Integrated Claus furnace, WHB, converters, sulfur condensers, TGTU recycle, incineration, and KPIs
Reactors reactors.md GibbsReactor
Pipelines pipelines.md Pipeline, AdiabaticPipe, TopsidePiping, Riser
Water Hammer Screening water_hammer_implementation.md WaterHammerPipe, WaterHammerStudy, MCP runWaterHammer
Piping Route Builder piping_route_builder.md PipingRouteBuilder for STID/E3D line-list route hydraulics
CO2 Well Analysis co2_injection_well_analysis.md CO2InjectionWellAnalyzer, ImpurityMonitor, TransientWellbore, CO2FlowCorrections
LNG Liquefaction lng_liquefaction.md LNGProcessBuilder, LNGProcessModel, LNGProcessBenchmark, LNGHeatExchanger
Hydrogen Production hydrogen_production.md SMR/ATR/POX route templates, ReformerFurnace, CatalyticTubeReformer, AutothermalReformer, PartialOxidationReactor, PSACascade, Electrolyzer
Looped Networks looped_networks.md LoopedPipeNetwork, Hardy Cross solver
Tanks tanks.md Tank, VesselDepressurization
Wells wells.md Well equipment
Subsea Trees subsea_trees.md SubseaTree, valve control
Subsea Manifolds subsea_manifolds.md SubseaManifold
Subsea Boosters subsea_boosters.md SubseaBooster, multiphase pumps
Umbilicals umbilicals.md Umbilical systems
Battery Storage battery_storage.md BatteryStorage
Heat Integration heat_integration.md PinchAnalysis, HeatStream
Power Generation power_generation.md GasTurbine, SteamTurbine, HRSG, CombinedCycleSystem, FuelCell, WindTurbine, SolarPanel
Failure Modes failure_modes.md EquipmentFailureMode, reliability
Mixers/Splitters mixers_splitters.md Mixer, Splitter
Utility util/ Adjuster, Recycle, Calculator

Package Structure

process/
├── SimulationBaseClass.java         # Base class for simulations
├── SimulationInterface.java         # Simulation interface
│
├── equipment/                        # Process equipment
│   ├── ProcessEquipmentBaseClass.java
│   ├── ProcessEquipmentInterface.java
│   ├── TwoPortEquipment.java         # Equipment with inlet/outlet
│   ├── EquipmentFactory.java         # Factory for creating equipment
│   │
│   ├── stream/                       # Streams
│   │   ├── Stream.java
│   │   ├── StreamInterface.java
│   │   ├── EnergyStream.java
│   │   └── VirtualStream.java
│   │
│   ├── separator/                    # Separators
│   │   ├── Separator.java
│   │   ├── ThreePhaseSeparator.java
│   │   ├── GasScrubber.java
│   │   └── SeparatorInterface.java
│   │
│   ├── heatexchanger/               # Heat transfer
│   │   ├── Heater.java
│   │   ├── Cooler.java
│   │   ├── HeatExchanger.java
│   │   ├── NeqHeater.java
│   │   └── Condenser.java
│   │
│   ├── compressor/                  # Compression
│   │   ├── Compressor.java
│   │   ├── CompressorInterface.java
│   │   └── CompressorChartInterface.java
│   │
│   ├── pump/                        # Pumps
│   │   ├── Pump.java
│   │   └── PumpInterface.java
│   │
│   ├── expander/                    # Expanders
│   │   ├── Expander.java
│   │   └── ExpanderInterface.java
│   │
│   ├── valve/                       # Valves
│   │   ├── ThrottlingValve.java
│   │   ├── ValveInterface.java
│   │   └── SafetyValve.java
│   │
│   ├── mixer/                       # Mixers
│   │   ├── Mixer.java
│   │   ├── StaticMixer.java
│   │   └── MixerInterface.java
│   │
│   ├── splitter/                    # Splitters
│   │   ├── Splitter.java
│   │   └── SplitterInterface.java
│   │
│   ├── distillation/                # Distillation
│   │   ├── DistillationColumn.java
│   │   ├── SimpleTray.java
│   │   ├── Condenser.java
│   │   └── Reboiler.java
│   │
│   ├── reactor/                     # Reactors
│   │   ├── Reactor.java
│   │   └── PFReactor.java
│   │
│   ├── absorber/                    # Absorption
│   │   ├── Absorber.java
│   │   └── SimpleTEGAbsorber.java
│   │
│   ├── pipeline/                    # Pipelines
│   │   ├── Pipeline.java
│   │   └── PipelineInterface.java
│   │
│   ├── well/                        # Wells
│   │   ├── SimpleWell.java
│   │   └── WellFlow.java
│   │
│   ├── tank/                        # Tanks and vessels
│   │   ├── Tank.java
│   │   └── ProcessVessel.java
│   │
│   ├── filter/                      # Filters
│   │   └── Filter.java
│   │
│   ├── membrane/                    # Membranes
│   │   └── Membrane.java
│   │
│   ├── ejector/                     # Ejectors
│   │   └── Ejector.java
│   │
│   ├── electrolyzer/                # Electrolyzers
│   │   └── PEM_Electrolyzer.java
│   │
│   └── util/                        # Utility equipment
│       ├── Adjuster.java
│       ├── Recycle.java
│       ├── Calculator.java
│       ├── Setter.java
│       └── MoleFractionSetter.java
│
├── processmodel/                    # Process system
│   ├── ProcessSystem.java
│   ├── ProcessModule.java
│   └── graph/                       # Graph-based execution
│       ├── ProcessGraph.java
│       └── ProcessGraphBuilder.java
│
├── controllerdevice/                # Controllers
│   ├── ControllerDevice.java
│   └── PIDController.java
│
├── measurementdevice/               # Measurements
│   ├── MeasurementDevice.java
│   ├── TemperatureMeasurement.java
│   ├── PressureMeasurement.java
│   └── FlowMeasurement.java
│
├── logic/                           # Process logic
│   ├── ProcessLogicController.java
│   └── ConditionalLogic.java
│
├── alarm/                           # Alarm system
│   └── ProcessAlarmManager.java
│
├── safety/                          # Safety systems
│   ├── PSV/
│   ├── ESD/
│   └── Blowdown/
│
├── calibration/                     # Equipment calibration
├── conditionmonitor/                # Condition monitoring
├── costestimation/                  # Cost estimation
├── mechanicaldesign/                # Mechanical design calculations
│   ├── separator/                   # Separator vessel design
│   ├── compressor/                  # Compressor design (API 617)
│   ├── valve/                       # Valve body, sizing, actuator
│   └── designstandards/             # ASME, API, IEC standards
├── mpc/                             # Model predictive control
├── ml/                              # Machine learning
└── streaming/                       # Data streaming

Mechanical Design Documentation

Equipment Documentation Standards
Separators See SeparatorMechanicalDesign ASME, BS 5500
Compressors CompressorMechanicalDesign.md API 617, API 672
Valves ValveMechanicalDesign.md IEC 60534, ANSI/ISA-75, ASME B16.34

ProcessSystem

The ProcessSystem class is the container for building and running process flowsheets.

Basic Usage

import neqsim.process.processmodel.ProcessSystem;
import neqsim.process.equipment.stream.Stream;
import neqsim.process.equipment.separator.Separator;
import neqsim.process.equipment.valve.ThrottlingValve;

// Create process system
ProcessSystem process = new ProcessSystem("Gas Processing Plant");

// Create feed stream
SystemInterface feed = new SystemSrkEos(300.0, 80.0);
feed.addComponent("methane", 0.85);
feed.addComponent("ethane", 0.08);
feed.addComponent("propane", 0.05);
feed.addComponent("n-butane", 0.02);
feed.setMixingRule("classic");

Stream feedStream = new Stream("Feed", feed);
feedStream.setFlowRate(1000.0, "kg/hr");

// Add equipment to process
process.add(feedStream);

// Letdown valve
ThrottlingValve valve = new ThrottlingValve("Inlet Valve", feedStream);
valve.setOutletPressure(40.0, "bara");
process.add(valve);

// Separator
Separator separator = new Separator("HP Separator", valve.getOutletStream());
process.add(separator);

// Run process (recommended - auto-optimized)
process.runOptimized();

// Get results
System.out.println("Separator gas rate: " +
    separator.getGasOutStream().getFlowRate("kg/hr") + " kg/hr");
System.out.println("Separator liquid rate: " +
    separator.getLiquidOutStream().getFlowRate("kg/hr") + " kg/hr");

Execution Strategies

NeqSim provides multiple execution strategies for optimal performance:

Method Best For Speedup
run() General use baseline
runOptimized() Recommended 28-40%
runParallel() Feed-forward (no recycles) 40-57%
runHybrid() Complex recycle processes 38% 
// Recommended - auto-selects best strategy
process.runOptimized();

// Or use specific strategies:
process.run();           // Sequential (default)
process.runParallel();   // Parallel (feed-forward only)
process.runHybrid();     // Hybrid (parallel + iterative)

Analyze Process Topology

// Check for recycles
boolean hasRecycles = process.hasRecycleLoops();

// Get detailed execution analysis
System.out.println(process.getExecutionPartitionInfo());

Key ProcessSystem Methods

Method Description
add(equipment) Add equipment to process
run() Run sequential simulation
runOptimized() Run with auto-optimized strategy
runParallel() Run with parallel execution
runHybrid() Run with hybrid execution
runTransient(time, dt) Run transient simulation
getUnit(name) Get equipment by name
hasRecycleLoops() Check for recycle loops
getExecutionPartitionInfo() Get execution analysis
copy() Clone the process system
getReport() Get process report
display() Display process summary

Equipment Categories

Streams

// Material stream
Stream gas = new Stream("Natural Gas", fluid);
gas.setFlowRate(5000.0, "Sm3/hr");
gas.setTemperature(25.0, "C");
gas.setPressure(100.0, "bara");
gas.run();

// Energy stream
EnergyStream heat = new EnergyStream("Heating Duty");
heat.setEnergyFlow(1000.0, "kW");

Separators

// Two-phase separator
Separator sep2p = new Separator("V-100", inletStream);
sep2p.run();
Stream gas = sep2p.getGasOutStream();
Stream liquid = sep2p.getLiquidOutStream();

// Three-phase separator
ThreePhaseSeparator sep3p = new ThreePhaseSeparator("V-200", inletStream);
sep3p.run();
Stream gas = sep3p.getGasOutStream();
Stream oil = sep3p.getOilOutStream();
Stream water = sep3p.getWaterOutStream();

Heat Exchangers

// Heater (duty specified)
Heater heater = new Heater("E-100", inletStream);
heater.setOutTemperature(80.0, "C");
heater.run();
System.out.println("Duty: " + heater.getDuty() + " W");

// Cooler
Cooler cooler = new Cooler("E-200", inletStream);
cooler.setOutTemperature(30.0, "C");
cooler.run();

// Shell-tube heat exchanger
HeatExchanger hx = new HeatExchanger("E-300", hotStream, coldStream);
hx.setUAvalue(5000.0);  // W/K
hx.run();

Compressors

// Compressor with polytropic efficiency
Compressor comp = new Compressor("K-100", inletStream);
comp.setOutletPressure(80.0, "bara");
comp.setPolytropicEfficiency(0.75);
comp.setUsePolytropicCalc(true);
comp.run();

System.out.println("Power: " + comp.getPower("kW") + " kW");
System.out.println("Outlet T: " + comp.getOutletStream().getTemperature("C") + " °C");

Valves

// Throttling valve (Joule-Thomson)
ThrottlingValve valve = new ThrottlingValve("FV-100", inletStream);
valve.setOutletPressure(50.0, "bara");
valve.run();

// Valve with Cv
valve.setCv(100.0, "US");
valve.setPercentValveOpening(50.0);

Distillation

// Simple distillation column
DistillationColumn column = new DistillationColumn("T-100", 10, true, true);
column.addFeedStream(feedStream, 5);
column.setCondenserTemperature(40.0, "C");
column.setReboilerTemperature(120.0, "C");
column.run();

Stream overhead = column.getGasOutStream();
Stream bottoms = column.getLiquidOutStream();

Controllers and Logic

Adjusters

Adjust a parameter to meet a specification.

// Adjust heater duty to achieve target temperature
Adjuster tempAdjuster = new Adjuster("TC-100");
tempAdjuster.setAdjustedVariable(heater, "duty");
tempAdjuster.setTargetVariable(heater.getOutletStream(), "temperature", 80.0, "C");
process.add(tempAdjuster);

Recycles

Handle recycle loops in the process.

Recycle recycle = new Recycle("Recycle");
recycle.addStream(recycleStream);
recycle.setOutletStream(recycleInletStream);
recycle.setTolerance(1e-6);
process.add(recycle);

Calculators

Perform custom calculations.

Calculator calc = new Calculator("MW Calculator");
calc.addInputVariable(stream);
calc.setOutputVariable(heater, "duty");
calc.setExpression("molarMass * 1000");
process.add(calc);

Safety Systems

Pressure Safety Valves

SafetyValve psv = new SafetyValve("PSV-100", vessel);
psv.setSetPressure(120.0, "bara");
psv.setBlowdownPressure(0.1);  // 10% blowdown
process.add(psv);

Blowdown Systems

See Safety Simulation Roadmap for detailed safety system documentation.

Dynamic Simulation

// Run transient simulation
double simulationTime = 3600.0;  // 1 hour
double timeStep = 1.0;           // 1 second

process.setTimeStep(timeStep);
for (double t = 0; t < simulationTime; t += timeStep) {
    process.runTransient();

    // Log data
    System.out.println(t + ", " +
        separator.getPressure() + ", " +
        separator.getGasOutStream().getFlowRate("kg/hr"));
}

Process Reports

// Get JSON report
String jsonReport = process.getReport_json();

// Get tabular report
String[][] table = process.getUnitOperationsAsTable();

// Display to console
process.display();

Best Practices

  1. Use unique names for all equipment
  2. Set flow rate and conditions before running
  3. Add equipment in flow order for clarity
  4. Use Recycle for recycle loops
  5. Check mass balance after simulation
  6. Clone streams before branching to avoid shared state

Future Infrastructure

NeqSim includes foundational infrastructure to support the future of process simulation:

Capability Documentation Description
Lifecycle Management lifecycle/ Model versioning, state export/import, lifecycle tracking
Emissions Tracking sustainability/ CO2e accounting, regulatory reporting
Advisory Systems advisory/ Look-ahead predictions with uncertainty
ML Integration ml/ Surrogate models, physics constraint validation
Safety Scenarios safety/scenario-generation.md Automatic failure scenario generation
Batch Studies optimization/batch-studies.md Parallel parameter studies

See Future Infrastructure Overview for complete documentation.