Gibbs Reactor

Represents a Gibbs Reactor that determines the equilibrium product composition by minimising the total Gibbs free energy of the system. Two solving approaches are available: direct minimisation (elemental balance constraints) and reaction-extent minimisation.

DWSIM.UnitOperations.Reactors.Reactor_Gibbs
Assembly DWSIM.UnitOperations.dll · Object ← BaseClass ← UnitOpBaseClass ← Reactor ← Reactor_Gibbs

At a glance

Port	Index	Connected in the example
Inlet, material	0	Feed
Inlet, energy	1	Q
Outlet, material	0	Syngas
Outlet, material	1	Liquid

Example

This code runs on every build of this site, and the output below is what it printed.

Python

compounds = ["Methane", "Water", "Carbon monoxide", "Carbon dioxide", "Hydrogen"]
fs = (Flowsheet.Create("GibbsReactorExample")
      .WithCompounds(*compounds)
      .WithPropertyPackage(PropertyPackages.PengRobinson))

# methane and steam, steam to carbon ratio 3
feed = (fs.AddMaterialStream("Feed")
        .At(Q.Celsius(850.0), Q.Bar(15.0))
        .WithMolarFlow(Q.MolPerSecond(4.0))
        .SetCompoundMolarFlow("Methane", 1.0)
        .SetCompoundMolarFlow("Water", 3.0))
syngas = fs.AddMaterialStream("Syngas")
liquid = fs.AddMaterialStream("Liquid")          # empty here, but the port must be connected
duty = fs.AddEnergyStream("Q")

reformer = (fs.AddGibbsReactor("R-1")
            .Isothermal()
            .WithPressureDrop(Q.Bar(0.0))
            .ConnectFeed(feed, 0)
            .ConnectProduct(syngas, 0)
            .ConnectProduct(liquid, 1)
            .ConnectEnergyFeed(duty, 1))
# compounds that take part in the minimization; the element matrix is built from the feed
ids = List[String]()
for c in compounds:
    ids.Add(c)
reformer.Object.ComponentIDs = ids
reformer.Object.CreateElementMatrix()

fs.AutoLayout()
fs.Solve()

y = {c: syngas.OverallMoleFraction(c) for c in compounds}
p_bar = 15.0
k_smr = y["Carbon monoxide"] * y["Hydrogen"] ** 3 * p_bar ** 2 / (y["Methane"] * y["Water"])
print(f"CH4 conversion       = {100.0 * reformer.Object.ComponentConversions['Methane']:.1f} %")
print(f"Syngas H2 / CO       = {100.0 * y['Hydrogen']:.2f} / {100.0 * y['Carbon monoxide']:.2f} mol %")
print(f"Syngas CH4           = {100.0 * y['Methane']:.2f} mol %")
print(f"Kp reforming         = {k_smr:.0f} bar2 (ln K = 30.114 - 26830/T: {math.exp(30.114 - 26830.0 / 1123.15):.0f} bar2)")
print(f"Heat supplied        = {reformer.HeatDutyKW:.1f} kW")

Output

CH4 conversion       = 89.1 %
Syngas H2 / CO       = 51.69 / 9.95 mol %
Syngas CH4           = 1.89 mol %
Kp reforming         = 529 bar2 (ln K = 30.114 - 26830/T: 506 bar2)
Heat supplied        = 191.3 kW

DWSIM 10.2.11.0, generated 2026-10-08.

Properties

IDs accepted by GetPropertyValue, SetPropertyValue, the sensitivity analysis, the optimizer, the Adjust block and dynamic events. Units are SI; pass another unit system to GetPropertyValue to get them converted.

ID	Name	Unit (SI)	Input
PROP_GR_0	Pressure Drop	Pa	yes
PROP_GR_1	Outlet Temperature	K	yes
Calculation Mode	Select the calculation mode of this reactor.		result
Initial Gibbs Energy		kW	result
Final Gibbs Energy		kW	result
Element Balance Residue			result
Methane: Conversion		%	result
Water: Conversion		%	result
Carbon monoxide: Conversion		%	result
Carbon dioxide: Conversion		%	result
Hydrogen: Conversion		%	result

Dynamic mode

Extra properties used when the flowsheet runs in dynamic mode.

Name	Unit
Operating Pressure (Dynamics)	Pa
Liquid Level	m
Volume	m3
Height	m
Minimum Pressure	Pa
Initialize using Inlet Stream
Reset Contents

Learn more

• User guide

  ---

  • Gibbs Reactor

• FluentAPI

  ---

  • GibbsReactorBuilder

API members

Public members declared by this class. Inherited members are documented on the base classes.

Constructors

Reactor_Gibbs(): Initializes a new default instance of the Reactor_Gibbs class.

Initializes a new default instance of the Reactor_Gibbs class.

C#VB.NET

public Reactor_Gibbs()

Public Sub New()

Reactor_Gibbs(string, string): Initializes a new instance of the Reactor_Gibbs class with a name and description.

Initializes a new instance of the Reactor_Gibbs class with a name and description.

Parameter	Type	Description
name	String	The display name of the Gibbs reactor.
description	String	A brief description of the Gibbs reactor.

C#VB.NET

public Reactor_Gibbs(string name, string description)

Public Sub New(name As String, description As String)

Properties

AlternateSolvingMethod: Gets or sets whether the alternate (Lagrange multiplier) solving method is used.

Gets or sets whether the alternate (Lagrange multiplier) solving method is used.

C#VB.NET

public bool AlternateSolvingMethod { get; set; }

Public Property AlternateSolvingMethod As Boolean

ComponentIDs: Gets or sets the list of compound IDs used in direct minimisation.

Gets or sets the list of compound IDs used in direct minimisation.

C#VB.NET

public List<string> ComponentIDs { get; set; }

Public Property ComponentIDs As List(Of String)

ComponentIDs_RE: Gets or sets the list of compound IDs used in reaction-extent mode.

Gets or sets the list of compound IDs used in reaction-extent mode.

C#VB.NET

public List<string> ComponentIDs_RE { get; set; }

Public Property ComponentIDs_RE As List(Of String)

DampingLowerLimit: Gets or sets the lower bound for the damping factor.

Gets or sets the lower bound for the damping factor.

C#VB.NET

public double DampingLowerLimit { get; set; }

Public Property DampingLowerLimit As Double

DampingUpperLimit: Gets or sets the upper bound for the damping factor.

Gets or sets the upper bound for the damping factor.

C#VB.NET

public double DampingUpperLimit { get; set; }

Public Property DampingUpperLimit As Double

DerivativePerturbation: Gets or sets the relative perturbation used for numerical derivative estimation.

Gets or sets the relative perturbation used for numerical derivative estimation.

C#VB.NET

public double DerivativePerturbation { get; set; }

Public Property DerivativePerturbation As Double

ElementBalance: Gets or sets the relative element balance error after convergence.

Gets or sets the relative element balance error after convergence.

C#VB.NET

public double ElementBalance { get; set; }

Public Property ElementBalance As Double

ElementMatrix: Gets or sets the element–compound formula matrix used for elemental balance constraints.

Gets or sets the element–compound formula matrix used for elemental balance constraints.

C#VB.NET

public double[,] ElementMatrix { get; set; }

Public Property ElementMatrix As Double(,)

Elements: Gets or sets the array of chemical element symbols involved in the minimisation.

Gets or sets the array of chemical element symbols involved in the minimisation.

C#VB.NET

public string[] Elements { get; set; }

Public Property Elements As String()

EnableDamping: Gets or sets whether damping is applied to the Newton step during the Lagrange method iteration.

Gets or sets whether damping is applied to the Newton step during the Lagrange method iteration.

C#VB.NET

public bool EnableDamping { get; set; }

Public Property EnableDamping As Boolean

FinalGibbsEnergy: Gets or sets the final total Gibbs free energy after minimisation.

Gets or sets the final total Gibbs free energy after minimisation.

C#VB.NET

public double FinalGibbsEnergy { get; set; }

Public Property FinalGibbsEnergy As Double

HasPropertiesForDynamicMode: Gets a value indicating whether this reactor exposes dedicated dynamic-mode properties.

Gets a value indicating whether this reactor exposes dedicated dynamic-mode properties.

C#VB.NET

public override bool HasPropertiesForDynamicMode { get; }

Public Overrides ReadOnly Property HasPropertiesForDynamicMode As Boolean

InitialEstimates: Gets or sets the list of user-supplied initial estimates for the minimisation variables.

Gets or sets the list of user-supplied initial estimates for the minimisation variables.

C#VB.NET

public List<double> InitialEstimates { get; set; }

Public Property InitialEstimates As List(Of Double)

InitialGibbsEnergy: Gets or sets the initial total Gibbs free energy before minimisation.

Gets or sets the initial total Gibbs free energy before minimisation.

C#VB.NET

public double InitialGibbsEnergy { get; set; }

Public Property InitialGibbsEnergy As Double

InitializeFromPreviousSolution: Gets or sets whether the solver initialises from the previous converged solution.

Gets or sets whether the solver initialises from the previous converged solution.

C#VB.NET

public bool InitializeFromPreviousSolution { get; set; }

Public Property InitializeFromPreviousSolution As Boolean

InternalTolerance: Gets or sets the convergence tolerance for the inner minimisation loop.

Gets or sets the convergence tolerance for the inner minimisation loop.

C#VB.NET

public double InternalTolerance { get; set; }

Public Property InternalTolerance As Double

LagrangeCoeffsEstimationTemperature: Gets or sets the temperature (K) used to estimate initial Lagrange coefficients.

Gets or sets the temperature (K) used to estimate initial Lagrange coefficients.

C#VB.NET

public double LagrangeCoeffsEstimationTemperature { get; set; }

Public Property LagrangeCoeffsEstimationTemperature As Double

MaximumInternalIterations: Gets or sets the maximum number of iterations for the inner minimisation loop.

Gets or sets the maximum number of iterations for the inner minimisation loop.

C#VB.NET

public int MaximumInternalIterations { get; set; }

Public Property MaximumInternalIterations As Integer

MobileCompatible: Gets a value indicating whether this reactor is compatible with mobile/cross-platform interfaces.

Gets a value indicating whether this reactor is compatible with mobile/cross-platform interfaces.

C#VB.NET

public override bool MobileCompatible { get; }

Public Overrides ReadOnly Property MobileCompatible As Boolean

PreviousSolution: Gets or sets the list of variable values from the previous solution, used for warm-starting.

Gets or sets the list of variable values from the previous solution, used for warm-starting.

C#VB.NET

public List<double> PreviousSolution { get; set; }

Public Property PreviousSolution As List(Of Double)

ReactionExtents: Gets the dictionary of calculated reaction extents, keyed by reaction ID.

Gets the dictionary of calculated reaction extents, keyed by reaction ID.

C#VB.NET

public Dictionary<string, double> ReactionExtents { get; }

Public ReadOnly Property ReactionExtents As Dictionary(Of String, Double)

ReactivePhaseBehavior: Gets or sets the reactive-phase behaviour for the Gibbs minimisation.

Gets or sets the reactive-phase behaviour for the Gibbs minimisation.

C#VB.NET

public Reactor_Gibbs.ReactivePhaseType ReactivePhaseBehavior { get; set; }

Public Property ReactivePhaseBehavior As Reactor_Gibbs.ReactivePhaseType

SupportsDynamicMode: Gets a value indicating whether this reactor supports dynamic simulation mode.

Gets a value indicating whether this reactor supports dynamic simulation mode.

C#VB.NET

public override bool SupportsDynamicMode { get; }

Public Overrides ReadOnly Property SupportsDynamicMode As Boolean

TotalElements: Gets or sets the array of total element amounts (mol) in the feed.

Gets or sets the array of total element amounts (mol) in the feed.

C#VB.NET

public double[] TotalElements { get; set; }

Public Property TotalElements As Double()

UseIPOPTSolver: Gets or sets whether the IPOPT solver is used for the Gibbs minimisation.

Gets or sets whether the IPOPT solver is used for the Gibbs minimisation.

C#VB.NET

public bool UseIPOPTSolver { get; set; }

Public Property UseIPOPTSolver As Boolean

Methods

Calculate(object): Performs the Gibbs reactor calculation, delegating to either direct minimisation or Lagrange multiplier method...

Performs the Gibbs reactor calculation, delegating to either direct minimisation or Lagrange multiplier method depending on the selected solving approach.

Parameter	Type	Description
args	Object	Optional. If True, indicates a dynamic-mode call.

C#VB.NET

public override void Calculate(object args = null)

Public Overrides Sub Calculate(args As Object = Nothing)

Calculate_GibbsMin(object): Solves the Gibbs minimisation using IPOPT or simplex subject to elemental balance constraints.

Solves the Gibbs minimisation using IPOPT or simplex subject to elemental balance constraints.

Parameter	Type	Description
args	Object

C#VB.NET

public void Calculate_GibbsMin(object args = null)

Public Sub Calculate_GibbsMin(args As Object = Nothing)

Calculate_Lagrange(object): Solves the Gibbs minimisation using the Lagrange multiplier (simultaneous correction) method.

Solves the Gibbs minimisation using the Lagrange multiplier (simultaneous correction) method.

Parameter	Type	Description
args	Object

C#VB.NET

public void Calculate_Lagrange(object args = null)

Public Sub Calculate_Lagrange(args As Object = Nothing)

CheckCompoundIDs(): Validates and updates the compound ID list, removing compounds no longer present in the simulation.

Validates and updates the compound ID list, removing compounds no longer present in the simulation.

C#VB.NET

public void CheckCompoundIDs()

Public Sub CheckCompoundIDs()

CloneXML(): Creates a deep copy of this reactor via XML serialization.

Creates a deep copy of this reactor via XML serialization.

C#VB.NET

public override object CloneXML()

Public Overrides Function CloneXML() As Object

CloseEditForm(): Closes and disposes the editing form.

Closes and disposes the editing form.

C#VB.NET

public override void CloseEditForm()

Public Overrides Sub CloseEditForm()

CreateDynamicProperties(): Registers the dynamic properties for dynamic simulation mode.

Registers the dynamic properties for dynamic simulation mode.

C#VB.NET

public override void CreateDynamicProperties()

Public Overrides Sub CreateDynamicProperties()

CreateElementMatrix(): Builds the element–compound formula matrix from the compound database, identifying which chemical elements are...

Builds the element–compound formula matrix from the compound database, identifying which chemical elements are present and their stoichiometric counts per compound.

C#VB.NET

public void CreateElementMatrix()

Public Sub CreateElementMatrix()

DeCalculate(): Clears the calculated results from the outlet material streams.

Clears the calculated results from the outlet material streams.

C#VB.NET

public override void DeCalculate()

Public Overrides Sub DeCalculate()

DisplayDynamicsEditForm(): Opens or activates the dynamics property editor form for this reactor.

Opens or activates the dynamics property editor form for this reactor.

C#VB.NET

public override void DisplayDynamicsEditForm()

Public Overrides Sub DisplayDynamicsEditForm()

DisplayEditForm(): Opens or activates the editing form for this reactor.

Opens or activates the editing form for this reactor.

C#VB.NET

public override void DisplayEditForm()

Public Overrides Sub DisplayEditForm()

GetDisplayDescription(): Returns the localised display description for this reactor.

Returns the localised display description for this reactor.

C#VB.NET

public override string GetDisplayDescription()

Public Overrides Function GetDisplayDescription() As String

GetDisplayName(): Returns the localised display name for this reactor.

Returns the localised display name for this reactor.

C#VB.NET

public override string GetDisplayName()

Public Overrides Function GetDisplayName() As String

GetIconBitmapBytes(): Returns the icon bitmap as a byte array.

Returns the icon bitmap as a byte array.

C#VB.NET

public override byte[] GetIconBitmapBytes()

Public Overrides Function GetIconBitmapBytes() As Byte()

GetProperties(PropertyType): Returns an array of property identifiers for the specified property type.

Returns an array of property identifiers for the specified property type.

Parameter	Type	Description
proptype	PropertyType

C#VB.NET

public override string[] GetProperties(PropertyType proptype)

Public Overrides Function GetProperties(proptype As PropertyType) As String()

GetPropertyDescription(string): Returns a human-readable description of the specified property.

Returns a human-readable description of the specified property.

Parameter	Type	Description
p	String

C#VB.NET

public override string GetPropertyDescription(string p)

Public Overrides Function GetPropertyDescription(p As String) As String

GetPropertyUnit(string, IUnitsOfMeasure): Returns the unit string for the specified property.

Returns the unit string for the specified property.

Parameter	Type	Description
prop	String
su	IUnitsOfMeasure

C#VB.NET

public override string GetPropertyUnit(string prop, IUnitsOfMeasure su = null)

Public Overrides Function GetPropertyUnit(prop As String, su As IUnitsOfMeasure = Nothing) As String

GetPropertyValue(string, IUnitsOfMeasure): Returns the value of the specified property, converted to the given unit system.

Returns the value of the specified property, converted to the given unit system.

Parameter	Type	Description
prop	String
su	IUnitsOfMeasure

C#VB.NET

public override object GetPropertyValue(string prop, IUnitsOfMeasure su = null)

Public Overrides Function GetPropertyValue(prop As String, su As IUnitsOfMeasure = Nothing) As Object

GetReport(IUnitsOfMeasure, CultureInfo, string): Generates a plain-text report of the reactor results using the specified units and format.

Generates a plain-text report of the reactor results using the specified units and format.

Parameter	Type	Description
su	IUnitsOfMeasure
ci	CultureInfo
numberformat	String

C#VB.NET

public override string GetReport(IUnitsOfMeasure su, CultureInfo ci, string numberformat)

Public Overrides Function GetReport(su As IUnitsOfMeasure, ci As CultureInfo, numberformat As String) As String

GetStructuredReport(): Generates a structured report of the reactor results as a list of typed tuples.

Generates a structured report of the reactor results as a list of typed tuples.

C#VB.NET

public override List<Tuple<ReportItemType, string[]>> GetStructuredReport()

Public Overrides Function GetStructuredReport() As List(Of Tuple(Of ReportItemType, String()))

LoadData(List<XElement>): Restores the reactor state, including element matrices and initial estimates, from XML.

Restores the reactor state, including element matrices and initial estimates, from XML.

Parameter	Type	Description
data	List<XElement>

C#VB.NET

public override bool LoadData(List<XElement> data)

Public Overrides Function LoadData(data As List(Of XElement)) As Boolean

RunDynamicModel(): Executes one dynamic simulation time step for the Gibbs reactor.

Executes one dynamic simulation time step for the Gibbs reactor.

C#VB.NET

public override void RunDynamicModel()

Public Overrides Sub RunDynamicModel()

SaveData(): Serializes the reactor state, including element matrices and compound lists, to XML.

Serializes the reactor state, including element matrices and compound lists, to XML.

C#VB.NET

public override List<XElement> SaveData()

Public Overrides Function SaveData() As List(Of XElement)

SetPropertyValue(string, object, IUnitsOfMeasure): Sets the value of the specified property from the given value and unit system.

Sets the value of the specified property from the given value and unit system.

Parameter	Type	Description
prop	String
propval	Object
su	IUnitsOfMeasure

C#VB.NET

public override bool SetPropertyValue(string prop, object propval, IUnitsOfMeasure su = null)

Public Overrides Function SetPropertyValue(prop As String, propval As Object, su As IUnitsOfMeasure = Nothing) As Boolean

UpdateEditForm(): Refreshes the editing form with updated data.

Refreshes the editing form with updated data.

C#VB.NET

public override void UpdateEditForm()

Public Overrides Sub UpdateEditForm()

Validate(): Validates that inlet and outlet streams are connected before calculation.

Validates that inlet and outlet streams are connected before calculation.

C#VB.NET

public override void Validate()

Public Overrides Sub Validate()

Fields

f: The classic (WinForms) editor window open for this reactor, if any.

The classic (WinForms) editor window open for this reactor, if any. Not saved with the flowsheet.

C#VB.NET

public object f

Public f As Object