Structured reference of what NeqSim can do, organized by engineering discipline. Use this to quickly check if a capability exists before searching the source code.
Last updated: 2026-03-23
A. Thermodynamic Models (Equations of State)
Cubic EOS
| Class | Fluid Type | Mixing Rule | Notes |
|---|---|---|---|
SystemSrkEos |
Dry/lean gas, simple HC | "classic" |
Most common choice |
SystemPrEos |
General HC, oil systems | "classic" |
Better liquid densities than SRK |
SystemPrEos1978 |
HC with Peng-Robinson 1978 | "classic" |
Updated alpha function |
SystemPrEosvolcor |
PR with volume correction | "classic" |
Volume-translated PR |
SystemSrkEosvolcor |
SRK with volume correction | "classic" |
Volume-translated SRK |
SystemSrkPenelouxEos |
SRK with Peneloux correction | "classic" |
Volume shift |
SystemSrkMathiasCopeman |
SRK + Mathias-Copeman alpha | "classic" |
Better vapor pressure fit |
SystemPrMathiasCopeman |
PR + Mathias-Copeman alpha | "classic" |
Better vapor pressure fit |
SystemSrkTwuCoonEos |
SRK + Twu-Coon alpha | "classic" |
TST-type alpha function |
SystemRKEos |
Redlich-Kwong (original) | "classic" |
Historical / teaching |
SystemPrDanesh |
PR-Danesh variant | "classic" |
Oil recovery applications |
SystemPsrkEos |
Predictive SRK (group contribution) | — | No BIPs needed for some systems |
SystemSrkSchwartzentruberEos |
SRK + Schwarzentruber-Renon | "classic" |
Polar compounds |
Association & Polar EOS (CPA)
| Class | Fluid Type | Mixing Rule | Notes |
|---|---|---|---|
SystemSrkCPAstatoil |
Water, MEG, methanol, polar | 10 (numeric) |
Primary CPA choice |
SystemSrkCPA |
CPA (generic) | 10 |
Base CPA |
SystemSrkCPAs |
CPA simplified | 10 |
Faster CPA variant |
SystemPrCPA |
PR-based CPA | 10 |
PR + association |
SystemElectrolyteCPAstatoil |
Brines, salt solutions | 10 |
Electrolyte + CPA |
SystemElectrolyteCPA |
Electrolyte CPA | 10 |
Base electrolyte |
Reference EOS (High Accuracy)
| Class | Fluid Type | Notes |
|---|---|---|
SystemGERG2008Eos |
Natural gas (custody transfer) | ISO 20765, highest accuracy |
SystemGERG2004Eos |
Natural gas (older GERG) | Predecessor to 2008 |
SystemSpanWagnerEos |
Pure CO2 | CO2 reference EOS |
SystemLeachmanEos |
Pure hydrogen | H2 reference EOS |
SystemWaterIF97 |
Pure water / steam | IAPWS-IF97 |
SystemVegaEos |
LNG / cryogenic | Specialized for LNG |
SAFT Family
| Class | Fluid Type | Notes |
|---|---|---|
SystemPCSAFT |
Polymers, associating | PC-SAFT |
SystemPCSAFTa |
PC-SAFT variant | Alternative parameterization |
Other / Specialized
| Class | Fluid Type | Notes |
|---|---|---|
SystemBWRSEos |
Benedict-Webb-Rubin-Starling | Only CH4 + C2H6 parameterized |
SystemIdealGas |
Ideal gas law | Teaching / reference |
SystemBnsEos |
BNS EOS | Specialized |
SystemUMRPRUEos |
UMRPRU group contribution | Predictive mixing rules |
SystemNRTL |
Activity coefficient (NRTL) | Liquid-liquid equilibrium |
SystemUNIFAC |
Activity coefficient (UNIFAC) | Group contribution |
SystemSoreideWhitson |
Soreide-Whitson for oil/water | HC-water mutual solubility |
SystemKentEisenberg |
Acid gas treating | H2S/CO2 in amines |
SystemDesmukhMather |
Acid gas treating | Amine systems |
SystemDuanSun |
CO2 in brine | CO2 solubility |
SystemAmmoniaEos |
Ammonia systems | NH3-specific |
Package: neqsim.thermo.system
B. Flash Calculations (ThermodynamicOperations)
| Method | Class/Operation | Notes |
|---|---|---|
| TP flash | ops.TPflash() |
Standard pressure-temperature |
| PH flash | ops.PHflash() |
Pressure-enthalpy |
| PS flash | ops.PSflash() |
Pressure-entropy |
| TV flash | ops.TVflash() |
Temperature-volume |
| UV flash | ops.UVflash() |
Internal energy-volume |
| Dew point P | ops.dewPointPressureFlash() |
At given T |
| Dew point T | ops.dewPointTemperatureFlash() |
At given P |
| Bubble point P | ops.bubblePointPressureFlash() |
At given T |
| Bubble point T | ops.bubblePointTemperatureFlash() |
At given P |
| Phase envelope | ops.calcPTphaseEnvelope() |
Full PT envelope |
| Cricondenbar | ops.calcPTphaseEnvelope() → .get("cricondenbar") |
Max pressure on envelope |
| Cricondentherm | ops.calcPTphaseEnvelope() → .get("cricondentherm") |
Max temperature on envelope |
| Solid flash | ops.TPSolidflash() |
Wax, hydrate, ice, S8 precipitation |
| Hydrate T | ops.hydrateEquilibriumTemperature() |
Hydrate formation temperature |
| Hydrate P | ops.hydrateFormationPressure() |
Hydrate formation pressure |
| Wax T | ops.calcWAT() |
Wax appearance temperature |
| Freeze T | ops.freezingPointTemperatureFlash() |
Freeze-out temperature |
| Water dew point | ops.waterDewPointTemperature() |
Water content specification |
CRITICAL: After any flash, call fluid.initProperties() before reading
transport properties (viscosity, thermal conductivity, density).
Package: neqsim.thermodynamicoperations
C. Process Equipment
Separation
| Class | Type | Package |
|---|---|---|
Separator |
2-phase (gas/liquid) | process.equipment.separator |
ThreePhaseSeparator |
3-phase (gas/oil/water) | process.equipment.separator |
GasScrubber |
Gas scrubbing | process.equipment.separator |
GasScrubberSimple |
Simplified scrubber | process.equipment.separator |
NeqSeparator |
Non-equilibrium separator | process.equipment.separator |
Compression & Expansion
| Class | Type | Package |
|---|---|---|
Compressor |
Centrifugal / reciprocating | process.equipment.compressor |
CompressorChart |
Performance curves | process.equipment.compressor |
Expander |
Turbo-expander | process.equipment.expander |
Heat Transfer
| Class | Type | Package |
|---|---|---|
Heater |
Generic heater (duty specification) | process.equipment.heatexchanger |
Cooler |
Generic cooler (duty specification) | process.equipment.heatexchanger |
HeatExchanger |
Shell-and-tube (2 streams) | process.equipment.heatexchanger |
NeqHeater |
Non-equilibrium heater | process.equipment.heatexchanger |
Valves & Pressure Control
| Class | Type | Package |
|---|---|---|
ThrottlingValve |
Isenthalpic flash | process.equipment.valve |
Distillation & Absorption
| Class | Type | Package |
|---|---|---|
DistillationColumn |
Tray column | process.equipment.distillation |
Condenser |
Column condenser | process.equipment.distillation |
Reboiler |
Column reboiler | process.equipment.distillation |
SimpleTEGAbsorber |
TEG absorption | process.equipment.absorber |
SimpleAbsorber |
Generic absorber | process.equipment.absorber |
WaterStripperColumn |
Water stripper | process.equipment.absorber |
Mixing & Splitting
| Class | Type | Package |
|---|---|---|
Mixer |
Stream mixing | process.equipment.mixer |
StaticMixer |
In-line mixer | process.equipment.mixer |
Splitter |
Stream splitting | process.equipment.splitter |
ComponentSplitter |
Component-based split | process.equipment.splitter |
Pipelines & CO2 Well Analysis
| Class | Type | Package |
|---|---|---|
AdiabaticPipe |
Adiabatic pipe flow | process.equipment.pipeline |
PipeBeggsAndBrills |
Beggs & Brill correlation (+ formation temperature gradient) | process.equipment.pipeline |
TwoFluidPipe |
Transient two-fluid multiphase model (OLGA-like) with 7 conservation equations, AUSM+, boundary conditions | process.equipment.pipeline |
CO2InjectionWellAnalyzer |
CO2 injection well safety analysis | process.equipment.pipeline |
TransientWellbore |
Shutdown cooling / depressurization transient | process.equipment.pipeline |
CO2FlowCorrections |
CO2-specific two-phase flow corrections (static utility) | process.equipment.pipeline |
InterfacialFriction |
Interfacial friction closures (Taitel-Dukler, Andritsos-Hanratty, Wallis, Oliemans) | process.equipment.pipeline.twophasepipe.closure |
OnePhasePipeFlowNode |
Single-phase pipe | fluidmechanics |
TwoPhasePipeFlowNode |
Two-phase pipe | fluidmechanics |
Reactors
| Class | Type | Package |
|---|---|---|
GibbsReactor |
Gibbs energy minimization | process.equipment.reactor |
GibbsReactorCO2 |
CO2-focused Gibbs reactor | process.equipment.reactor |
StoichiometricReaction |
Stoichiometric reactions | process.equipment.reactor |
StirredTankReactor |
CSTR | process.equipment.reactor |
FurnaceBurner |
Combustion | process.equipment.reactor |
SulfurDepositionAnalyser |
S8 deposition analysis | process.equipment.reactor |
AmmoniaSynthesisReactor |
NH3 synthesis | process.equipment.reactor |
AnaerobicDigester |
Biogas production (AD) | process.equipment.reactor |
FermentationReactor |
Monod/Contois/substrate-inhibited kinetics | process.equipment.reactor |
BiogasUpgrader |
Biogas upgrading (membrane, PSA, amine, water scrub) | process.equipment.splitter |
BiomassGasifier |
Thermochemical gasification | process.equipment.reactor |
PyrolysisReactor |
Fast/slow/flash pyrolysis | process.equipment.reactor |
Biorefinery Modules (Pre-built)
| Class | Type | Package |
|---|---|---|
BiogasToGridModule |
AD → upgrading → compression → grid | process.processmodel.biorefinery |
GasificationSynthesisModule |
Biomass gasification + Fischer-Tropsch | process.processmodel.biorefinery |
WasteToEnergyCHPModule |
AD → gas engine CHP | process.processmodel.biorefinery |
Sustainability & Cost
| Class | Type | Package |
|---|---|---|
SustainabilityMetrics |
CO₂eq tracking, carbon intensity, EROI | process.util.fielddevelopment |
BiomassCharacterization |
Biomass properties (proximate, ultimate, HHV) | thermo.characterization |
BiorefineryCostEstimator |
CAPEX/OPEX for biorefinery equipment | process.mechanicaldesign |
Measurement Devices & Instrumentation
| Class | Type | Package |
|---|---|---|
ImpurityMonitor |
Phase-partitioned impurity tracker with alarms | process.measurementdevice |
PressureTransmitter |
Pressure measurement (PT) | process.measurementdevice |
TemperatureTransmitter |
Temperature measurement (TT) | process.measurementdevice |
LevelTransmitter |
Level measurement (LT) | process.measurementdevice |
VolumeFlowTransmitter |
Volume flow measurement (FT) | process.measurementdevice |
MassFlowTransmitter |
Mass flow measurement | process.measurementdevice |
WaterDewPointAnalyser |
Water dew point measurement | process.measurementdevice |
HydrocarbonDewPointAnalyser |
HC dew point measurement | process.measurementdevice |
WaterContentAnalyser |
Water content measurement | process.measurementdevice |
CO2waterAnalyser |
CO2 in water measurement | process.measurementdevice |
AlarmConfig |
Alarm HH/H/L/LL thresholds per IEC 61511 | process.measurementdevice |
AlarmState |
Current alarm state tracking | process.measurementdevice |
ProcessAlarmManager |
System-wide alarm management | process.measurementdevice |
InstrumentTagRole |
Tag role classification (INPUT/BENCHMARK/VIRTUAL) | process.measurementdevice |
ControllerDeviceBaseClass |
PID controller base | process.equipment.controller |
DynamicProcessHelper |
Auto-instruments and controls a ProcessSystem | process.equipment.util |
Pumps
| Class | Type | Package |
|---|---|---|
Pump |
Liquid pump | process.equipment.pump |
Subsea & Wells
| Class | Type | Package |
|---|---|---|
SubseaWell |
Subsea well model | process.equipment.subsea |
Utilities & Special
| Class | Type | Package |
|---|---|---|
Recycle |
Stream recycle convergence | process.equipment.util |
Adjuster |
Variable adjuster | process.equipment.util |
SetPoint |
Set point controller | process.equipment.util |
Calculator |
Custom calculator | process.equipment.util |
StreamSaturatorUtil |
Stream saturation | process.equipment.util |
GasGenerator |
Gas generation | process.equipment.util |
Flare |
Flare system | process.equipment.flare |
Filter |
Particle filter | process.equipment.filter |
Ejector |
Ejector / eductor | process.equipment.ejector |
Electrolyzer |
Water electrolysis | process.equipment.electrolyzer |
Tank |
Storage tank | process.equipment.tank |
Manifold |
Subsea manifold | process.equipment.manifold |
SimpleReservoir |
Simple reservoir model | process.equipment.reservoir |
Process System
| Class | Type | Package |
|---|---|---|
ProcessSystem |
Flowsheet container | process.processmodel |
ProcessConnection |
Equipment connections | process.processmodel |
D. PVT Simulations
| Class | Experiment | Package |
|---|---|---|
ConstantMassExpansion |
CME / CCE | pvtsimulation.simulation |
ConstantVolumeDepletion |
CVD | pvtsimulation.simulation |
DifferentialLiberation |
Differential liberation | pvtsimulation.simulation |
SeparatorTest |
Multi-stage separator test | pvtsimulation.simulation |
SwellingTest |
Gas injection swelling | pvtsimulation.simulation |
SaturationPressure |
Bubble/dew point P | pvtsimulation.simulation |
SaturationTemperature |
Bubble/dew point T | pvtsimulation.simulation |
SlimTube |
Slim tube / MMP | pvtsimulation.simulation |
ViscositySimulation |
Viscosity vs P | pvtsimulation.simulation |
GOR |
Gas-oil ratio vs P | pvtsimulation.simulation |
Flow Assurance (PVT module)
| Class | Assessment | Package |
|---|---|---|
DeWaardMilliamsCorrosion |
CO2/H2S corrosion rate | pvtsimulation.flowassurance |
Regression / Tuning
| Class | Purpose | Package |
|---|---|---|
ModelTuning |
EOS parameter fitting | pvtsimulation.modeltuning |
E. Gas Quality Standards
| Class | Standard | Package |
|---|---|---|
Standard_ISO6976 |
ISO 6976 — calorific value, Wobbe, density | standards.gasquality |
Standard_ISO6976_2016 |
ISO 6976:2016 update | standards.gasquality |
Standard_ISO6578 |
ISO 6578 — LNG custody transfer | standards.gasquality |
Standard_ISO15403 |
ISO 15403 — natural gas for vehicles | standards.gasquality |
Standard_EN16726 |
EN 16726 — European gas quality | standards.gasquality |
UKgasQuality |
UK gas quality specification | standards.gasquality |
GasChromatographData |
GC data processing | standards.gasquality |
BrackettedMolarComposition |
Molar composition bracketing | standards.gasquality |
Draft_GERG2004 |
GERG-2004 draft implementation | standards.gasquality |
SulfurSpecificationMethod |
H2S / total sulfur limits | standards.gasquality |
Oil Quality
| Class | Standard | Package |
|---|---|---|
Standard_ASTM_D6377 |
ASTM D6377 — vapor pressure | standards.oilquality |
Standard_ASTM_D2887 |
ASTM D2887 — simulated distillation | standards.oilquality |
Standard_ASTM_D4294 |
ASTM D4294 — sulfur in oil | standards.oilquality |
F. Mechanical Design
| Class | Equipment | Package |
|---|---|---|
MechanicalDesign |
Base class | process.mechanicaldesign |
SeparatorMechanicalDesign |
Separator vessel sizing, K-factor, demister config, nozzle sizing, liquid levels (HHLL/HLL/NLL/LLL/LLLL), inlet device, foam allowance, retention time, entrainment performance, design validation. Gateway for all separator physical configuration. Bridge methods: entrainment (setInletPipeDiameter, setInletDeviceType, addSeparatorSection, setGasLiquidSurfaceTension) and dynamic internals (setWeirHeightAbsolute, setWeirLength, setBootVolume, setMistEliminatorDpCoeff, setMistEliminatorThickness, applyDemistingInternal). |
process.mechanicaldesign.separator |
DemistingInternal |
Demisting internal sizing — Souders-Brown max gas velocity, Eu-number pressure drop, carry-over model. Types: wire mesh, vane pack, cyclone. | process.mechanicaldesign.separator.internals |
DemistingInternalWithDrainage |
Demisting internal with drainage section — reduces carry-over by drainage efficiency factor. | process.mechanicaldesign.separator.internals |
PrimarySeparation |
Inlet device base — inlet momentum (rho*v^2), momentum limit checking, liquid carry-over with degradation. | process.mechanicaldesign.separator.primaryseparation |
InletVane |
Inlet vane device (6000 Pa max momentum, 85% bulk efficiency). | process.mechanicaldesign.separator.primaryseparation |
InletVaneWithMeshpad |
Inlet vane + downstream mesh pad (92% + mesh pad capture). | process.mechanicaldesign.separator.primaryseparation |
InletCyclones |
Inlet cyclone cluster (8000 Pa max momentum, 95% bulk efficiency). | process.mechanicaldesign.separator.primaryseparation |
PipelineMechanicalDesign |
Pipeline wall thickness | process.mechanicaldesign.pipeline |
CompressorMechanicalDesign |
Compressor design | process.mechanicaldesign.compressor |
ValveMechanicalDesign |
Valve mechanical design | process.mechanicaldesign.valve |
HeatExchangerMechanicalDesign |
HX mechanical design with auto-selection (min area/weight/dP) | process.mechanicaldesign.heatexchanger |
CompressorDesignFeasibilityReport |
Compressor feasibility (design + cost + suppliers + curves) | process.mechanicaldesign.compressor |
HeatExchangerDesignFeasibilityReport |
HX/cooler/heater feasibility (design + cost + suppliers) | process.mechanicaldesign.heatexchanger |
ThermalDesignCalculator |
Tube/shell-side HTCs, overall U, pressure drops, zone analysis | process.mechanicaldesign.heatexchanger |
BellDelawareMethod |
Bell-Delaware shell-side HTC & dP with J-factor corrections | process.mechanicaldesign.heatexchanger |
LMTDcorrectionFactor |
LMTD F_t for multi-pass configurations (Bowman-Mueller-Nagle) | process.mechanicaldesign.heatexchanger |
VibrationAnalysis |
Flow-induced vibration screening per TEMA RCB-4.6 | process.mechanicaldesign.heatexchanger |
ShellAndTubeDesignCalculator |
Full TEMA-based S&T design with ASME VIII, NACE, thermal, cost | process.mechanicaldesign.heatexchanger |
WellMechanicalDesign |
Well casing design | process.mechanicaldesign.subsea |
WellDesignCalculator |
API 5C3 calculations | process.mechanicaldesign.subsea |
WellCostEstimator |
Well cost estimation | process.mechanicaldesign.subsea |
SURFCostEstimator |
Subsea CAPEX | process.mechanicaldesign.subsea |
SubseaCostEstimator |
Regional cost factors | process.mechanicaldesign.subsea |
FieldDevelopmentDesignOrchestrator |
Full field design | process.mechanicaldesign |
MotorMechanicalDesign |
Motor foundation, vibration, cooling, bearings, noise, enclosure | process.mechanicaldesign.motor |
EquipmentDesignReport |
Combined mech + elec + motor design report with verdict | process.mechanicaldesign |
Engineering Deliverables
| Class | Purpose | Package |
|---|---|---|
StudyClass |
Enum (CLASS_A/CLASS_B/CLASS_C) defining required deliverables per study tier | process.mechanicaldesign |
EngineeringDeliverablesPackage |
Orchestrates generation of all deliverables for a study class | process.mechanicaldesign |
ProcessFlowDiagramExporter |
Graphviz DOT export of ProcessSystem topology | process.processmodel |
ThermalUtilitySummary |
Cooling water, LP/MP/HP steam, fuel gas, instrument air | process.mechanicaldesign |
AlarmTripScheduleGenerator |
Alarm/trip setpoints per IEC 61511 / NORSOK I-001 | process.mechanicaldesign |
InstrumentScheduleGenerator |
ISA-5.1 tagged instrument schedule with live MeasurementDevice bridge | process.mechanicaldesign |
SparePartsInventory |
Recommended spare parts by equipment type with lead times | process.mechanicaldesign |
FireProtectionDesign |
Jet fire, BLEVE, pool fire scenario assessment (API 521) | process.mechanicaldesign.designstandards |
NoiseAssessment |
Equipment noise + ISO 9613-2 atmospheric attenuation | process.mechanicaldesign.designstandards |
Electrical Design
| Class | Purpose | Package |
|---|---|---|
ElectricalDesign |
Base class — sizes motor, VFD, cables, switchgear | process.electricaldesign |
ElectricalMotor |
AC induction motor model (IEC 60034, IEEE 841) | process.electricaldesign.components |
VariableFrequencyDrive |
VFD with topology, harmonics, efficiency | process.electricaldesign.components |
ElectricalCable |
Cable sizing with derating (IEC 60502) | process.electricaldesign.components |
Transformer |
Power transformer model (IEC 60076) | process.electricaldesign.components |
Switchgear |
MCC / switchgear bucket (IEC 61439) | process.electricaldesign.components |
HazardousAreaClassification |
Zone / Ex marking (IEC 60079) | process.electricaldesign.components |
CompressorElectricalDesign |
Compressor-specific with auxiliary loads | process.electricaldesign.compressor |
PumpElectricalDesign |
Pump-specific design | process.electricaldesign.pump |
SeparatorElectricalDesign |
Separator auxiliary loads | process.electricaldesign.separator |
HeatExchangerElectricalDesign |
Electric heater / air cooler / S&T detection | process.electricaldesign.heatexchanger |
PipelineElectricalDesign |
Heat tracing, cathodic protection | process.electricaldesign.pipeline |
SystemElectricalDesign |
Plant-wide load aggregation, transformer sizing | process.electricaldesign.system |
ElectricalLoadList |
Load list with demand/diversity factors | process.electricaldesign.loadanalysis |
G. Physical Properties
| Class | Property | Package |
|---|---|---|
PhysicalPropertyHandler |
Property dispatcher | physicalproperties |
| Viscosity models | Gas/liquid/mixing rule | physicalproperties.methods |
| Thermal conductivity | Gas/liquid | physicalproperties.methods |
| Diffusion coefficients | Binary diffusion | physicalproperties.methods |
Access pattern: After fluid.initProperties(), use:
fluid.getPhase("gas").getViscosity("kg/msec")fluid.getPhase("gas").getThermalConductivity("W/mK")fluid.getPhase("gas").getDensity("kg/m3")
H. Utility Classes
| Class | Purpose | Package |
|---|---|---|
FluidBuilder |
Fluent fluid construction | thermo.system |
HeatMaterialBalance |
Process-wide H&M balance | util.engineering |
SensitivityAnalysis |
Parametric sweeps | util.engineering |
MonteCarloSimulator |
Monte Carlo sampling | util.engineering |
ConvergenceDiagnostics |
Solver diagnostics | util.engineering |
HydrateRiskMapper |
Hydrate risk matrix | util.engineering |
EOSComparison |
Multi-EOS comparison | util.engineering |
PinchAnalyzer |
Pinch analysis (heat integration) | util.engineering |
DCFCalculator |
NPV / DCF economics | util.engineering |
DebottleneckAnalyzer |
Capacity bottleneck finding | util.engineering |
ProcessValidator |
Equipment validation | util.engineering |
CoolingWaterSystem |
Cooling water sizing | process.equipment.heatexchanger |
FiredHeater |
Fired heater modeling | process.equipment.heatexchanger |
I. Chemical Reactions
| Capability | Implementation | Notes |
|---|---|---|
| Gibbs energy minimization | GibbsReactor |
Newton-Raphson, element balanced |
| Stoichiometric reactions | StoichiometricReaction |
User-defined reactions |
| Combustion | FurnaceBurner |
Fuel gas combustion |
| Sulfur reactions | SulfurDepositionAnalyser |
Claus + corrosion reactions |
| Ammonia synthesis | AmmoniaSynthesisReactor |
Haber-Bosch |
| Chemical equilibrium DB | GibbsReactDatabase.csv |
Thermodynamic data |
I-bis. Bioprocessing & Bioenergy
| Capability | Implementation | Notes |
|---|---|---|
| Anaerobic digestion | AnaerobicDigester |
Substrate-specific biogas yields (food waste, sewage, manure, crop residue) |
| Fermentation kinetics | FermentationReactor |
Monod, Contois, substrate-inhibited; batch, fed-batch, continuous |
| Biogas upgrading | BiogasUpgrader |
Water scrubbing, amine, PSA, membrane; auto CH4/CO2 split |
| Biomass gasification | BiomassGasifier |
Air/oxygen/steam; syngas composition from biomass properties |
| Pyrolysis | PyrolysisReactor |
Fast, slow, flash; bio-oil, char, gas yields |
| Sustainability / LCA | SustainabilityMetrics |
CO₂eq (IPCC AR6 GWP), carbon intensity, EROI, renewable fraction |
| Biomass characterization | BiomassCharacterization |
Proximate, ultimate analysis; HHV correlations |
| Biorefinery costing | BiorefineryCostEstimator |
Equipment-level CAPEX/OPEX estimation |
| Biogas-to-grid chain | BiogasToGridModule |
Pre-built: AD → upgrading → compression → grid |
| Gasification + FT | GasificationSynthesisModule |
Pre-built: biomass → syngas → Fischer-Tropsch liquids |
| Waste-to-energy CHP | WasteToEnergyCHPModule |
Pre-built: AD → gas engine with electrical + thermal output |
I-ter. Equipment Diagnostics & Reliability
| Capability | Implementation | Notes |
|---|---|---|
| Root cause analysis | RootCauseAnalyzer |
Bayesian-inspired RCA with multi-source reliability priors |
| Symptom-based diagnosis | Symptom enum (12 symptoms) |
TRIP, HIGH_VIBRATION, SURGE, FOULING, etc. |
| Hypothesis generation | HypothesisGenerator |
Built-in libraries for compressor, pump, separator, HX, valve |
| Time-series evidence | EvidenceCollector |
Trend, threshold, rate-of-change, correlation, multi-parameter pattern |
| Simulation verification | SimulationVerifier |
Clone-perturb-compare with graduated severity |
| Reliability data | ReliabilityDataSource |
IOGP/SINTEF, CCPS, IEEE 493, Lees, OREDA (9 sources, 4 CSVs) |
| Equipment failure modes | EquipmentFailureMode |
MTBF/MTTR/failure rate calculations |
| Diagnostic reporting | RootCauseReport |
JSON, text, ranked hypotheses with confidence scores |
| Custom hypothesis registry | HypothesisGenerator.register() |
Domain-specific hypothesis extension |
Package: neqsim.process.diagnostics, neqsim.process.equipment.failure
J. Known Gaps and Limitations
Major Gaps (commonly requested but missing or incomplete)
| Gap | Description | Workaround |
|---|---|---|
| Rate-based distillation | No mass-transfer-rate column model | Use equilibrium stages with efficiency |
| Asphaltene modeling | Limited asphaltene precipitation | Use PC-SAFT with tuned parameters |
| Scale prediction | No mineral scale model | External tool (ScaleChem) |
| Erosion modeling | No erosion rate calculation | API RP 14E velocity check only |
| Detailed heat exchanger design | TEMA-level design with Bell-Delaware, vibration, ASME VIII | Full thermal-hydraulic + mechanical via ShellAndTubeDesignCalculator |
| Dynamic simulation | Limited transient capability | runTransient() on ProcessSystem |
| Reservoir coupling | Simple reservoir only | No full reservoir simulator |
| Control system simulation | PID controllers + AlarmConfig + InstrumentScheduleGenerator + DynamicProcessHelper | No DCS/SIS emulation |
| Amine sweetening | Basic Kent-Eisenberg / DM | No rate-based amine model |
| Membrane separation | Basic membrane model | No detailed permeation |
| BWRS EOS | Only CH4 + C2H6 parameterized | Use SRK/PR instead |
| NACE MR0175 material selection | No systematic material logic | Manual standard lookup |
| Detailed flare modeling | No radiation / noise model | Source term only |
| Full pipeline network | LoopedPipeNetwork: NR-GGA solver, 120+ wells, IPR (PI/Vogel/Fetkovich), chokes, tubing VLP, Beggs-Brill multiphase, compressors, regulators, artificial lift (gas lift/ESP/jet/rod pump), water handling, sand erosion (DNV RP O501), corrosion (de Waard-Milliams/NORSOK M-506), GHG emissions tracking | Full-featured production network |
EOS Limitations
| EOS | Known Limitation |
|---|---|
| SRK/PR | Poor near critical point; liquid density without volume correction |
| CPA | Slower convergence; limited component database for association |
| GERG-2008 | Only natural gas components (21 components) |
| PC-SAFT | Limited BIP database; slower than cubic EOS |
| BWRS | Only 2 components parameterized |
Component Database Limitations
| Component Type | Coverage |
|---|---|
| Light HCs (C1-C10) | ✅ Excellent |
| Heavy HCs (C11-C36) | ✅ Good (TBP fractions) |
| Common gases (N2, CO2, H2S, H2, O2) | ✅ Excellent |
| Water, MEG, methanol, TEG | ✅ Good (CPA parameterized) |
| Amines (MEA, DEA, MDEA) | ⚠️ Limited |
| Sulfur species (S8, SO2, COS) | ⚠️ Partial |
| Ionic species | ⚠️ Limited database |
| Polymers | ⚠️ Few PC-SAFT parameters |
| Refrigerants | ⚠️ Some available |
| Specialty chemicals | ❌ Case-by-case |
K. Reservoir & Production Properties
| Class | Purpose | Package |
|---|---|---|
GasPseudoCriticalProperties |
Pseudo-critical T, P | pvtsimulation.reservoirproperties |
CompositionEstimation |
Reservoir fluid estimation | pvtsimulation.reservoirproperties |
ZFactorCorrelations |
Z-factor (Standing, DAK, etc.) | pvtsimulation.reservoirproperties |
SimpleReservoir |
Material balance reservoir | process.equipment.reservoir |
Well |
Well inflow model | process.equipment.well |
Quick Lookup: "Can NeqSim do X?"
| Question | Answer | Class/Method |
|---|---|---|
| Phase envelope? | ✅ | ops.calcPTphaseEnvelope() |
| Hydrate temperature? | ✅ | ops.hydrateEquilibriumTemperature() |
| Wax appearance? | ✅ | ops.calcWAT() |
| CO2 corrosion rate? | ✅ | DeWaardMilliamsCorrosion |
| H2S sour classification? | ✅ | DeWaardMilliamsCorrosion.isSourService() |
| ISO 6976 calorific value? | ✅ | Standard_ISO6976 |
| Pipeline sizing? | ✅ | PipeBeggsAndBrills + PipelineMechanicalDesign |
| Compressor power? | ✅ | Compressor.getPower("kW") |
| NPV / DCF? | ✅ | DCFCalculator |
| Well casing design? | ✅ | WellDesignCalculator |
| TEG dehydration? | ✅ | SimpleTEGAbsorber |
| Sulfur deposition? | ✅ | SulfurDepositionAnalyser |
| JT cooling? | ✅ | ThrottlingValve |
| Depressurization? | ✅ | ProcessSystem.runTransient() |
| Monte Carlo? | ✅ | MonteCarloSimulator |
| Heat integration? | ✅ | PinchAnalyzer |
| Amine sweetening? | ⚠️ Basic | Kent-Eisenberg model |
| Biogas production? | ✅ | AnaerobicDigester |
| Fermentation kinetics? | ✅ | FermentationReactor (Monod/Contois) |
| Biogas upgrading? | ✅ | BiogasUpgrader (4 technologies) |
| Biomass gasification? | ✅ | BiomassGasifier |
| Sustainability / LCA? | ✅ | SustainabilityMetrics |
| Biogas-to-grid module? | ✅ | BiogasToGridModule |
| Waste-to-energy CHP? | ✅ | WasteToEnergyCHPModule |
| Rate-based column? | ❌ | Not available |
| Scale prediction? | ❌ | Not available |
| Detailed HX design? | ❌ | Use duty + LMTD |
| Full reservoir sim? | ❌ | SimpleReservoir only |
| CO2 injection well analysis? | ✅ | CO2InjectionWellAnalyzer |
| CO2 wellbore shutdown transient? | ✅ | TransientWellbore |
| CO2 flow corrections? | ✅ | CO2FlowCorrections |
| Impurity monitoring? | ✅ | ImpurityMonitor |
| Formation temperature gradient? | ✅ | PipeBeggsAndBrills.setFormationTemperatureGradient() |
| Motor sizing? | ✅ | ElectricalMotor.sizeMotor() |
| Motor foundation design? | ✅ | MotorMechanicalDesign |
| Motor vibration check? | ✅ | MotorMechanicalDesign.getVibrationZone() |
| Electrical load list? | ✅ | ElectricalLoadList |
| Combined design report? | ✅ | EquipmentDesignReport |
| VFD selection? | ✅ | VariableFrequencyDrive |
| Cable sizing? | ✅ | ElectricalCable |
| Hazardous area classification? | ✅ | HazardousAreaClassification |