Absorption Column¶

Rigorous absorption column: a staged column without condenser or reboiler, solved by the equilibrium stage solvers of the Column base class. In extractor mode (OperationMode) it models a liquid-liquid extraction column.

DWSIM.UnitOperations.UnitOperations.AbsorptionColumn
Assembly DWSIM.UnitOperations.dll · Object ← BaseClass ← UnitOpBaseClass ← Column ← AbsorptionColumn

At a glance¶

Absorption Column in the example flowsheet

Port	Index	Connected in the example
Inlet, material	`0`	Lean water
Inlet, material	`1`	Solvent-laden air
Inlet, material	`2`
Inlet, material	`3`
Inlet, material	`4`
Inlet, material	`5`
Inlet, material	`6`
Inlet, material	`7`
Inlet, material	`8`
Inlet, material	`9`
Outlet, material	`0`	Clean gas
Outlet, material	`1`	Rich water
Outlet, material	`2`
Outlet, material	`3`
Outlet, material	`4`
Outlet, material	`5`
Outlet, material	`6`
Outlet, material	`7`
Outlet, material	`8`
Outlet, material	`9`

Example¶

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

Python

fs = (Flowsheet.Create("AbsorptionColumnExample")
      .WithCompounds("Water", "Acetone", "Nitrogen")
      .WithPropertyPackage(PropertyPackages.NRTL))

water = (fs.AddMaterialStream("Lean water")
         .At(Q.Celsius(25.0), Q.Bar(1.01325))
         .WithMolarFlow(Q.MolPerSecond(150.0))
         .SetCompoundMolarFlow("Water", 150.0))
gas = (fs.AddMaterialStream("Solvent-laden air")
       .At(Q.Celsius(30.0), Q.Bar(1.01325))
       .WithMolarFlow(Q.MolPerSecond(20.0))
       .SetCompoundMolarFlow("Acetone", 0.4)
       .SetCompoundMolarFlow("Nitrogen", 19.6))
clean_gas = fs.AddMaterialStream("Clean gas")
rich_water = fs.AddMaterialStream("Rich water")

column = (fs.AddAbsorptionColumn("ABS-1")
          .WithNumberOfStages(10)
          .WithFeed(water, "Stage1")       # liquid enters at the top
          .WithFeed(gas, "Stage10")        # gas enters at the bottom
          .WithTopProduct(clean_gas)
          .WithBottoms(rich_water)
          .WithTopPressure(Q.Bar(1.01325))
          .WithColumnPressureDrop(Q.Bar(0.0)))

fs.AutoLayout()
fs.Solve()

acetone_in = gas.MolarFlowMolPerSecond * gas.OverallMoleFraction("Acetone")
acetone_out = clean_gas.MolarFlowMolPerSecond * clean_gas.OverallMoleFraction("Acetone")
print(f"Acetone in clean gas = {clean_gas.OverallMoleFraction('Acetone') * 1e6:.0f} ppm (molar)")
print(f"Acetone recovery     = {100.0 * (1.0 - acetone_out / acetone_in):.2f} %")
print(f"Acetone in water     = {rich_water.OverallMoleFraction('Acetone'):.4f} (mole fraction)")
print(f"Clean gas T          = {clean_gas.TemperatureK - 273.15:.1f} C")
print(f"Rich water T         = {rich_water.TemperatureK - 273.15:.1f} C")

Output

Acetone in clean gas = 203 ppm (molar)
Acetone recovery     = 98.97 %
Acetone in water     = 0.0026 (mole fraction)
Clean gas T          = 25.0 C
Rich water T         = 23.9 C

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.

All 71 properties

ID	Name	Unit (SI)	Input
`PROP_AC_0`	Top Stage Pressure	Pa	yes
`PROP_AC_1`	Bottom Stage Pressure	Pa	yes
`PROP_AC_2`	Number of Stages		result
`Stage_Efficiency_1`			yes
`Stage_DowncomerLength_1`		m	yes
`Stage_DowncomerHeight_1`		m	yes
`Stage_TotalHoleArea_1`		m2	yes
`Stage_LiquidLevel_1`		m	yes
`Stage_Height_1`		m	yes
`Stage_Efficiency_2`			yes
`Stage_DowncomerLength_2`		m	yes
`Stage_DowncomerHeight_2`		m	yes
`Stage_TotalHoleArea_2`		m2	yes
`Stage_LiquidLevel_2`		m	yes
`Stage_Height_2`		m	yes
`Stage_Efficiency_3`			yes
`Stage_DowncomerLength_3`		m	yes
`Stage_DowncomerHeight_3`		m	yes
`Stage_TotalHoleArea_3`		m2	yes
`Stage_LiquidLevel_3`		m	yes
`Stage_Height_3`		m	yes
`Stage_Efficiency_4`			yes
`Stage_DowncomerLength_4`		m	yes
`Stage_DowncomerHeight_4`		m	yes
`Stage_TotalHoleArea_4`		m2	yes
`Stage_LiquidLevel_4`		m	yes
`Stage_Height_4`		m	yes
`Stage_Efficiency_5`			yes
`Stage_DowncomerLength_5`		m	yes
`Stage_DowncomerHeight_5`		m	yes
`Stage_TotalHoleArea_5`		m2	yes
`Stage_LiquidLevel_5`		m	yes
`Stage_Height_5`		m	yes
`Stage_Efficiency_6`			yes
`Stage_DowncomerLength_6`		m	yes
`Stage_DowncomerHeight_6`		m	yes
`Stage_TotalHoleArea_6`		m2	yes
`Stage_LiquidLevel_6`		m	yes
`Stage_Height_6`		m	yes
`Stage_Efficiency_7`			yes
`Stage_DowncomerLength_7`		m	yes
`Stage_DowncomerHeight_7`		m	yes
`Stage_TotalHoleArea_7`		m2	yes
`Stage_LiquidLevel_7`		m	yes
`Stage_Height_7`		m	yes
`Stage_Efficiency_8`			yes
`Stage_DowncomerLength_8`		m	yes
`Stage_DowncomerHeight_8`		m	yes
`Stage_TotalHoleArea_8`		m2	yes
`Stage_LiquidLevel_8`		m	yes
`Stage_Height_8`		m	yes
`Stage_Efficiency_9`			yes
`Stage_DowncomerLength_9`		m	yes
`Stage_DowncomerHeight_9`		m	yes
`Stage_TotalHoleArea_9`		m2	yes
`Stage_LiquidLevel_9`		m	yes
`Stage_Height_9`		m	yes
`Stage_Efficiency_10`			yes
`Stage_DowncomerLength_10`		m	yes
`Stage_DowncomerHeight_10`		m	yes
`Stage_TotalHoleArea_10`		m2	yes
`Stage_LiquidLevel_10`		m	yes
`Stage_Height_10`		m	yes
`Stream 'Lean water' Stage Index`			yes
`Stream 'Solvent-laden air' Stage Index`			yes
`Stream 'Clean gas' Stage Index`			yes
`Stream 'Rich water' Stage Index`			yes
`Estimated Height`		mm	yes
`Estimated Diameter`		mm	yes
`Number of Stages`			yes
`Sump_LiquidLevel`		m	yes

Dynamic mode¶

Extra properties used when the flowsheet runs in dynamic mode.

Name	Unit
Max. P change (%)
Max. L change (%)
Max. V change (%)
Time step discretization
Souders-Brown Coefficient
Flooding Alarm
Weeping Alarm
Apply Murphree Efficiency
Quasi-Steady Vapor
Calibrate Tray Coefficients
Start Empty
Initial Pressure
Initial Temperature
Initial Sump Level
Minimum Pressure
Coolant Temperature
Tray Weeping

Learn more¶

User guide
- Rigorous Absorption Column
FluentAPI
- AbsorptionColumnBuilder
- Columns

API members¶

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

Constructors¶

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

Initializes a new default instance of the AbsorptionColumn class.

C#VB.NET

public AbsorptionColumn()

Public Sub New()

AbsorptionColumn(string, string, IFlowsheet): Initializes a new instance of the AbsorptionColumn class with a name and description, creates the default stages and...

Initializes a new instance of the AbsorptionColumn class with a name and description, creates the default stages and sets every stage pressure to 101325 Pa.

Parameter	Type	Description
`name`	`String`	The name of this unit operation.
`description`	`String`	A brief description of this unit operation.
`fs`	`IFlowsheet`	The flowsheet that owns this column.

C#VB.NET

public AbsorptionColumn(string name, string description, IFlowsheet fs)

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

Properties¶

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 True.

C#VB.NET

public override bool MobileCompatible { get; }

Public Overrides ReadOnly Property MobileCompatible As Boolean

OperationMode: Gets or sets the operation mode: Absorber (0) for gas-liquid absorption, Extractor (1) for liquid-liquid extraction...

Gets or sets the operation mode: Absorber (0) for gas-liquid absorption, Extractor (1) for liquid-liquid extraction, where the solvers treat the two phases as two liquids.

C#VB.NET

public AbsorptionColumn.OpMode OperationMode { get; set; }

Public Property OperationMode As AbsorptionColumn.OpMode

Methods¶

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

ConnectBottoms(ISimulationObject): Connects the bottoms liquid product stream to the bottom stage of the column.

Connects the bottoms liquid product stream to the bottom stage of the column.

Parameter	Type	Description
`stream`	`ISimulationObject`	The material stream that receives the bottoms product.

C#VB.NET

public void ConnectBottoms(ISimulationObject stream)

Public Sub ConnectBottoms(stream As ISimulationObject)

ConnectFeed(ISimulationObject, int): Connects a feed to a stage by its zero-based index: 0 is the top stage (the condenser, which the editor calls...

Connects a feed to a stage by its zero-based index: 0 is the top stage (the condenser, which the editor calls Stage1), so the editor's StageN is index N - 1.

Parameter	Type	Description
`feed`	`ISimulationObject`
`stagenumber`	`Int32`

C#VB.NET

public void ConnectFeed(ISimulationObject feed, int stagenumber)

Public Sub ConnectFeed(feed As ISimulationObject, stagenumber As Integer)

ConnectFeed(ISimulationObject, string): Connects a feed to the stage named as the editor shows it, e.g.

Connects a feed to the stage named as the editor shows it, e.g. "Stage10" (Stage1 is the condenser when there is one).

Parameter	Type	Description
`feed`	`ISimulationObject`
`stageName`	`String`

C#VB.NET

public void ConnectFeed(ISimulationObject feed, string stageName)

Public Sub ConnectFeed(feed As ISimulationObject, stageName As String)

ConnectTopProduct(ISimulationObject): Connects the top product.

Connects the top product. This column's top product leaves stage 0 as the overhead stream V(0), so it is marked OverheadVapor - the same behaviour the UI stores. Distillate means a liquid drawn off stage 0 at rate LSS(0), which for an absorber is zero, and the product's flow would then be left out of the closing mass balance entirely.

Parameter	Type	Description
`stream`	`ISimulationObject`

C#VB.NET

public void ConnectTopProduct(ISimulationObject stream)

Public Sub ConnectTopProduct(stream As ISimulationObject)

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

Returns the localized description string for this unit operation type.

C#VB.NET

public override string GetDisplayDescription()

Public Overrides Function GetDisplayDescription() As String

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

Returns the localized 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()

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 = null)

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

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

GetReport(IUnitsOfMeasure, CultureInfo, string): Generates a plain-text results report for this unit operation: number of stages and the stage temperature, pressure...

Generates a plain-text results report for this unit operation: number of stages and the stage temperature, pressure, vapor flow and liquid flow profiles.

Parameter	Type	Description
`su`	`IUnitsOfMeasure`	The unit system used for formatting output values.
`ci`	`CultureInfo`	The culture info used for number formatting.
`numberformat`	`String`	A .NET numeric format string (e.g. "G6") applied to output values.

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

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 = null)

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

Fields¶

_opmode: Backing field for OperationMode.

Backing field for OperationMode. Default OpMode.Absorber.

C#VB.NET

public AbsorptionColumn.OpMode _opmode

Public _opmode As AbsorptionColumn.OpMode