Alkylation Unit¶

DWSIM Plus

Available with a DWSIM Plus (Patreon) subscription.

Shortcut Alkylation unit. Two inlets (iso-butane, olefin feed) → two outlets (alkylate, LPG purge). Mass balance is olefin-limited: reacted olefin × yield factor = alkylate mass; everything else goes to purge. Exothermic heat is rejected on the energy connector. Outlets are emitted as moles of a single surrogate compound each (Isooctane / n-Butane by default).

DWSIM.UnitOperations.Refining.Alkylation.AlkylationUnitOperation
Assembly DWSIM.UnitOperations.Refining.dll · Object ← BaseClass ← UnitOpBaseClass ← AlkylationUnitOperation

At a glance¶

Alkylation Unit in the example flowsheet

Port	Index	Connected in the example
Inlet, material	`0`	iC4
Inlet, material	`1`	Butenes
Outlet, material	`0`	Alkylate
Outlet, material	`1`	LPG-purge
Outlet, energy	`2`	Refrigeration

Example¶

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

Python

fs = (Flowsheet.Create("AlkylationExample")
      .WithCompounds("Isobutane", "1-Butene", "N-butane", "2,2,4-trimethylpentane")
      .WithPropertyPackage(PropertyPackages.PengRobinson))

# Isobutane (with recycle) and a butene feed, both liquid at 10 bar.
# The unit treats the whole olefin inlet as olefin, so feed it olefin only.
isobutane = (fs.AddMaterialStream("iC4").At(Q.Celsius(10.0), Q.Bar(10.0))
             .SetCompoundMassFlow("Isobutane", 6.0)                     # kg/s
             .SetCompoundMassFlow("N-butane", 0.3))
olefin = (fs.AddMaterialStream("Butenes").At(Q.Celsius(10.0), Q.Bar(10.0))
          .SetCompoundMassFlow("1-Butene", 1.0))
alkylate = fs.AddMaterialStream("Alkylate")
purge = fs.AddMaterialStream("LPG-purge")
cooling = fs.AddEnergyStream("Refrigeration")

alky = (fs.AddAlkylation("ALK-1")
        .WithOperatingTemperature(Q.Celsius(10.0))
        .WithOperatingPressure(Q.Bar(7.0))
        .WithOlefinConversion(0.98)
        .WithAlkylateYieldPerKgOlefin(1.78)     # kg alkylate per kg olefin reacted
        .WithAlkylateRON(95.0)
        .ConnectFeed(isobutane, 0).ConnectFeed(olefin, 1)
        .ConnectProduct(alkylate, 0).ConnectProduct(purge, 1))
# The reaction heat leaves through outlet port 2
alky.ConnectEnergyProduct(cooling, 2)

fs.AutoLayout()
fs.Solve()

r = alky.Object.Results
print(f"Alkylate          = {alkylate.MassFlowKgPerSecond:.3f} kg/s (RON {r.AlkylateRON:.0f})")
print(f"LPG purge         = {purge.MassFlowKgPerSecond:.3f} kg/s")
print(f"Olefin reacted    = {r.OlefinReactedMass:.3f} kg/s")
print(f"iC4/olefin ratio  = {r.IsoButaneOlefinRatio:.2f} mol/mol")
print(f"Refrigeration     = {cooling.EnergyFlowKW:.0f} kW")

Output

Alkylate          = 1.744 kg/s (RON 95)
LPG purge         = 5.556 kg/s
Olefin reacted    = 0.980 kg/s
iC4/olefin ratio  = 6.08 mol/mol
Refrigeration     = 1078 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
`Operating Temperature`	K	yes
`Operating Pressure`	Pa	yes
`Olefin Conversion`	NF	yes
`IsoButane/Olefin Ratio`	NF	yes
`Alkylate Yield Per Kg Olefin`	NF	yes
`Alkylate RON`	NF	yes
`Total Feed Mass`	kg/s	result
`Alkylate Mass Flow`	kg/s	result
`Purge Mass Flow`	kg/s	result
`Cooler Duty`	kW	result

Learn more¶

User guide
- Alkylation Unit
FluentAPI
- Refining.AlkylationBuilder

API members¶

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

Constructors¶

AlkylationUnitOperation()

C#VB.NET

public AlkylationUnitOperation()

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 configuration of this alkylation unit: the operating temperature and pressure, olefin conversion...

Gets or sets the configuration of this alkylation unit: the operating temperature and pressure, olefin conversion, iso-butane to olefin molar ratio, alkylate yield and heat release per kg of olefin, alkylate RON, and the alkylate and purge surrogate compounds.

C#VB.NET

public AlkylationConfiguration Config { get; set; }

Public Property Config As AlkylationConfiguration

IsRefining: Gets a value indicating that this unit operation belongs to the refining group.

Gets a value indicating that this unit operation belongs to the refining group. Always true; the object palette uses it to list the unit under the Refinery 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 ('ALK-').

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

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: two inlets (iso-Butane and Olefin Feed) on the left, two...

Creates the graphic connector definitions on the flowsheet: two inlets (iso-Butane and Olefin Feed) on the left, two outlets (Alkylate and Purge) on the right, and a Cooler Duty energy outlet.

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 it cannot be loaded), draw mode 1 draws the vector icon as a silhouette, and other modes draw 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, rendered from the vector icon at 64 x 64 pixels.

Returns the raw bytes of the icon image for this unit operation, rendered from the vector icon at 64 x 64 pixels.

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 (Avalonia) editor panel with controls: buttons that open the configuration and results...

Populates the cross-platform (Avalonia) editor panel with controls: buttons that open the configuration and results forms. Other container types are ignored.

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).

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 FormEditorAlkylation _editorForm

Public _editorForm As FormEditorAlkylation