Isomerization Unit¶

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Shortcut C5/C6 Isomerization unit. One light-naphtha inlet → two material outlets (isomerate, light ends) + mild endothermic heater duty on the energy connector. Both outlets are emitted as moles of a single surrogate compound each (isopentane / propane by default).

DWSIM.UnitOperations.Refining.Isomerization.IsomerizationUnitOperation
Assembly DWSIM.UnitOperations.Refining.dll · Object ← BaseClass ← UnitOpBaseClass ← IsomerizationUnitOperation

At a glance¶

Isomerization Unit in the example flowsheet

Port	Index	Connected in the example
Inlet, material	`0`	Light-naphtha
Inlet, energy	`1`	Heater-duty
Outlet, material	`0`	Isomerate
Outlet, material	`1`	Light-ends

Example¶

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

Python

# The isomerate leaves as isopentane and the light ends as propane (surrogates).
fs = (Flowsheet.Create("IsomerizationExample")
      .WithCompounds("Propane", "N-pentane", "Isopentane", "N-hexane", "Cyclohexane", "Benzene")
      .WithPropertyPackage(PropertyPackages.PengRobinson))

feed = fs.AddMaterialStream("Light-naphtha").At(Q.Celsius(40.0), Q.Bar(30.0))
for name, kg_s in {"N-pentane": 4.0, "Isopentane": 2.0, "N-hexane": 3.5,
                   "Cyclohexane": 0.3, "Benzene": 0.2}.items():
    feed.SetCompoundMassFlow(name, kg_s)                   # 10 kg/s in total
isomerate = fs.AddMaterialStream("Isomerate")
light_ends = fs.AddMaterialStream("Light-ends")
heater = fs.AddEnergyStream("Heater-duty")

iso = (fs.AddIsomerization("ISOM-1")
       .WithReactorTemperature(Q.Celsius(150.0))
       .WithReactorPressure(Q.Bar(30.0))
       .WithLHSV(2.0)
       .WithBaseIsomerateYield(0.97)
       .WithBaseLightEndsYield(0.03)
       .WithIsomerateRON(87.0)
       .ConnectFeed(feed, 0).ConnectEnergyFeed(heater, 1)
       .ConnectProduct(isomerate, 0).ConnectProduct(light_ends, 1))

fs.AutoLayout()
fs.Solve()

r = iso.Object.Results
print(f"Feed aromatics    = {r.FeedPNA.xA * 100.0:.1f} wt%")
print(f"Isomerate         = {isomerate.MassFlowKgPerSecond:.3f} kg/s ({isomerate.MassFlowKgPerSecond / r.FeedMassFlow * 100.0:.1f} wt%)")
print(f"Light ends        = {light_ends.MassFlowKgPerSecond:.3f} kg/s")
print(f"RON               = {r.FeedRON:.0f} -> {r.IsomerateRON:.0f}")
print(f"Heater duty       = {heater.EnergyFlowKW:.0f} kW")

Output

Feed aromatics    = 2.0 wt%
Isomerate         = 9.845 kg/s (98.5 wt%)
Light ends        = 0.155 kg/s
RON               = 70 -> 87
Heater duty       = 3145 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	Unit (SI)	Input
`Reactor Temperature`	K	yes
`Reactor Pressure`	Pa	yes
`LHSV`	1/h	yes
`Isomerate Yield`	NF	yes
`Isomerate RON`	NF	yes
`Heater Duty Per Kg Feed`	J/kg	yes
`Feed Mass Flow`	kg/s	result
`Isomerate Mass Flow`	kg/s	result
`Light Ends Mass Flow`	kg/s	result
`Isomerate RON Out`	NF	result
`Heater Duty`	kW	result
`Heater Duty Estimate`	kW	result
`Feed xP`	NF	result
`Feed xN`	NF	result
`Feed xA`	NF	result

Learn more¶

User guide
- Isomerization Unit
FluentAPI
- Refining.IsomerizationBuilder

API members¶

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

Constructors¶

IsomerizationUnitOperation()

C#VB.NET

public IsomerizationUnitOperation()

Public Sub New()

Properties¶

ComponentDescription: Gets or sets the CAPE-OPEN component description for this unit operation.

Gets or sets the CAPE-OPEN component description for this unit operation.

C#VB.NET

public override string ComponentDescription { get; set; }

Public Overrides Property ComponentDescription As String

Config: Gets or sets the isomerization configuration: reactor temperature and pressure, LHSV, heater duty per kg of feed...

Gets or sets the isomerization configuration: reactor temperature and pressure, LHSV, heater duty per kg of feed, base isomerate and light ends yields, feed PNA aromatics correction, feed and isomerate RON, sulfur and nitrogen partition fractions, and the surrogate compounds for the two outlets (Isopentane and Propane by default). Saved with the flowsheet.

C#VB.NET

public IsomerizationConfiguration Config { get; set; }

Public Property Config As IsomerizationConfiguration

IsRefining: Gets a value that is always true.

Gets a value that is always true. It marks this class as a refining unit operation, so the flowsheet object palettes (which read it by reflection) list it under the Refining category.

C#VB.NET

public bool IsRefining { get; }

Public ReadOnly Property IsRefining As Boolean

MobileCompatible: Gets a value indicating whether this unit operation is compatible with mobile interfaces.

Gets a value indicating whether this unit operation is compatible with mobile interfaces. Always false.

C#VB.NET

public override bool MobileCompatible { get; }

Public Overrides ReadOnly Property MobileCompatible As Boolean

ObjectClass: Gets the simulation object class category (Reactors).

Gets the simulation object class category (Reactors).

C#VB.NET

public override SimulationObjectClass ObjectClass { get; }

Public Overrides Property ObjectClass As SimulationObjectClass

Prefix: Gets the default name prefix for this unit operation ('ISO-').

Gets the default name prefix for this unit operation ("ISO-").

C#VB.NET

public string Prefix { get; }

Public ReadOnly Property Prefix As String

Methods¶

Calculate(object): Calculates the object.

Calculates the object.

Parameter	Type	Description
`args`	`Object`

C#VB.NET

public override void Calculate(object args = null)

Public Overrides Sub Calculate(args As Object = Nothing)

CloneXML(): Creates a deep copy of this object by round-tripping through XML serialization.

Creates a deep copy of this object by round-tripping through XML serialization.

C#VB.NET

public override object CloneXML()

Public Overrides Function CloneXML() As Object

CloseEditForm(): Closes the editor of this object, if it is open.

Closes the editor of this object, if it is open.

C#VB.NET

public override void CloseEditForm()

Public Overrides Sub CloseEditForm()

CreateConnectors(): Creates the graphic connector definitions on the flowsheet: the light naphtha inlet ('Light Naphtha') on the left...

Creates the graphic connector definitions on the flowsheet: the light naphtha inlet ("Light Naphtha") on the left edge, the heater duty energy port ("Heater Duty") on the bottom edge, and two material outlets on the right edge ("Isomerate", "Light Ends"). The standard energy connector is disabled.

C#VB.NET

public void CreateConnectors()

Public Sub CreateConnectors()

DeCalculate(): Decalculates the object.

Decalculates the object.

C#VB.NET

public override void DeCalculate()

Public Overrides Sub DeCalculate()

DisplayEditForm(): Opens the editor of this object.

Opens the editor of this object. A host that has no editor for it does nothing.

C#VB.NET

public override void DisplayEditForm()

Public Overrides Sub DisplayEditForm()

Draw(object): Draws the unit operation icon on the given SkiaSharp canvas.

Draws the unit operation icon on the given SkiaSharp canvas. Draw mode 2 uses the embedded PNG image (falling back to the vector icon if the image cannot be loaded), draw mode 1 draws the vector icon as a silhouette, and any other mode draws the vector icon.

Parameter	Type	Description
`g`	`Object`	The SkiaSharp canvas (`SKCanvas`).

C#VB.NET

public void Draw(object g)

Public Sub Draw(g As Object)

GetDisplayDescription(): Returns the description string for this unit operation type.

Returns the description string for this unit operation type.

C#VB.NET

public override string GetDisplayDescription()

Public Overrides Function GetDisplayDescription() As String

GetDisplayName(): Returns the display name for this unit operation type.

Returns the display name for this unit operation type.

C#VB.NET

public override string GetDisplayName()

Public Overrides Function GetDisplayName() As String

GetIconBitmapBytes(): Returns the raw bytes of the icon image for this unit operation.

Returns the raw bytes of the icon image for this unit operation.

C#VB.NET

public override byte[] GetIconBitmapBytes()

Public Overrides Function GetIconBitmapBytes() As Byte()

GetPreferredGraphicObjectHeight(): Returns the preferred height of the flowsheet graphic object, in pixels.

Returns the preferred height of the flowsheet graphic object, in pixels.

C#VB.NET

public override double GetPreferredGraphicObjectHeight()

Public Overrides Function GetPreferredGraphicObjectHeight() As Double

GetPreferredGraphicObjectWidth(): Returns the preferred width of the flowsheet graphic object, in pixels.

Returns the preferred width of the flowsheet graphic object, in pixels.

C#VB.NET

public override double GetPreferredGraphicObjectWidth()

Public Overrides Function GetPreferredGraphicObjectWidth() As Double

GetProperties(PropertyType): Get a list of all properties of the object.

Get a list of all properties of the object.

Parameter	Type	Description
`proptype`	`PropertyType`	Type of the property.

C#VB.NET

public override string[] GetProperties(PropertyType proptype)

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

GetPropertyUnit(string, IUnitsOfMeasure): Gets the units of a property.

Gets the units of a property.

Parameter	Type	Description
`prop`	`String`	Property identifier.
`su`	`IUnitsOfMeasure`	Units system to use. Null to use the default (SI) system.

C#VB.NET

public override string GetPropertyUnit(string prop, IUnitsOfMeasure su)

Public Overrides Function GetPropertyUnit(prop As String, su As IUnitsOfMeasure) As String

GetPropertyValue(string, IUnitsOfMeasure): Returns the value of a named property, converting from SI to the current unit system.

Returns the value of a named property, converting from SI to the current unit system. Falls back to extra properties if the property is not found in the base implementation.

Parameter	Type	Description
`prop`	`String`	The property identifier string.
`su`	`IUnitsOfMeasure`	Optional units-of-measure system used for conversion; uses the shared SI system when `Nothing`.

C#VB.NET

public override object GetPropertyValue(string prop, IUnitsOfMeasure su)

Public Overrides Function GetPropertyValue(prop As String, su As IUnitsOfMeasure) As Object

LoadData(List<XElement>): Restores the unit operation state from a list of XML elements previously produced by SaveData.

Restores the unit operation state from a list of XML elements previously produced by SaveData.

Parameter	Type	Description
`data`	`List<XElement>`	The list of `XElement` objects containing serialized state.

C#VB.NET

public override bool LoadData(List<XElement> data)

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

PopulateEditorPanel(object): Populates the cross-platform editor panel with controls.

Populates the cross-platform editor panel with controls. Only the Avalonia editor panel (AvaloniaEditorPanel) is filled; other container types are left unchanged.

Parameter	Type	Description
`ctner`	`Object`	The editor panel (layout container) to populate.

C#VB.NET

public void PopulateEditorPanel(object ctner)

Public Sub PopulateEditorPanel(ctner As Object)

ReturnInstance(string): Creates and returns a new instance for deserialization.

Creates and returns a new instance for deserialization.

Parameter	Type	Description
`typename`	`String`	The type name to instantiate. Not used; a new `IsomerizationUnitOperation` is always returned.

C#VB.NET

public object ReturnInstance(string typename)

Public Function ReturnInstance(typename As String) As Object

SaveData(): Serializes the unit operation state to a list of XML elements for persistence.

Serializes the unit operation state to a list of XML elements for persistence.

C#VB.NET

public override List<XElement> SaveData()

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

SetPropertyValue(string, object, IUnitsOfMeasure): Sets the value of a property.

Sets the value of a property.

Parameter	Type	Description
`prop`	`String`	Property identifier.
`propval`	`Object`	Property value to set at the specified units.
`su`	`IUnitsOfMeasure`	Units system to use. Null to use the default (SI) system.

C#VB.NET

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

Public Overrides Function SetPropertyValue(prop As String, propval As Object, su As IUnitsOfMeasure) As Boolean

UpdateEditForm(): Redraws the editor of this object with the current values, if it is open.

Redraws the editor of this object with the current values, if it is open.

C#VB.NET

public override void UpdateEditForm()

Public Overrides Sub UpdateEditForm()

Fields¶

_editorForm: The classic (WinForms) editor window open for this unit operation, if any.

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

C#VB.NET

public FormEditorIsomerization _editorForm

Public _editorForm As FormEditorIsomerization