© 2024 Jasper van Baten, AmsterCHEM


Welcome to the Excel CAPE-OPEN unit operation. This is a steady-state CAPE-OPEN unit operation that allows you to do calculation in Microsoft Excel. A CAPE-OPEN unit operation can be plugged in to CAPE-OPEN compliant simulation environments. Main-stream process simulators have support for CAPE-OPEN. As an example, you can use this unit operation in the free CAPE-OPEN flowsheet simulator COCO.

Getting started

To get started, insert the unit operation into a CAPE-OPEN based flowsheet environment. Then, edit the unit operation. Excel will open allowing you to edit the spread sheet that defines the unit operation's calculations.

On the feeds sheet, you can add and remove material feed streams. On the products sheet, you can add or remove product streams. Similarly, you can add and remove in- and output parameters on the input parameters and output parameters sheets.

To define a working unit operation, you will need to specify formulas that calculate the product streams and output parameters. At this point it is useful that the unit operation knows about the thermodynamics. It only knows this once you have connected at least one stream to a feed or product port. So now that you have configured feed and product ports, close Excel and return to the simulation environment. At this point, connect one or more streams to the unit operation. Make sure that thermodynamic have already been configured in the simulation environment, so that the streams will tell the unit operation about which chemical compounds are present.

Go back to editing the unit. Excel will re-open. At this point you should see the feed conditions, as far as they have been specified. The feeds and products sheets will also list the compounds that are present.

For each product, you will need to specify formulas to calculate the product stream. Specify a formula for the stream's composition and the total flow. Also, 2 out of 3 of pressure, temperature and enthalpy must be specified; two specifications of these variables are requires in order for the unit operation to be able to calculate the thermodynamic equilibrium.

You can also at this point specify formulas to calculate the output parameter values.

In your formulas, you can use functions for thermodynamic calculations. A short summary of these functions is provided on the control sheet. This sheet also allows you to inspect which thermodynamic properties and phases are supported. Click the appropriate button for more information.

Only help

To access this help from with Excel, click the Help Help button on the Unit Operation ribbon.


The Excel CAPE-OPEN Unit Operation requires a working version of Microsoft Excel, version 2010 or higher, to be installed at your system.

The Excel unit operations requires User Defined Functions (UDFs). These are stored in the AmsterCHEM Excel CAPE-OPEN Unit Operation UDF Add-In, which is by default installed and activated. Without this Add-In, the calculations will not work properly. To make sure the Add-In is installed and active, click Excel Options from the Office menu, go to the Add-Ins tab, select to manage Excel Add-Ins:

Excel Add-Ins

If the Add-In is not registered, please re-install the Excel CAPE-OPEN Unit Operation software.

Also shown in the above is the Excel Solver Add-in, which may come in handy for solving non-explicit equations. If the solver is not available, you can located it from the Excel library folder using Browse.

Your Excel model is saved as xlsx file, which means you cannot use Macros in your Excel book. If you need to use Macros, you need to supply your own XLS add-in (e.g. a .xlam file).

Missing references will be resolved, but you might be prompted

If you have saved your unit operation using Excel 2010, the next time you open it on a different machine, you may find that the reference to the Add-In has not been stored properly. Excel may ask you to do something about it when opening the document:

Update links

Please answer No; the Excel Unit Operation will fix the links immediately after loading the workbook.

If you are loading the Excel unit Operation on a different system with Excel 2010, you may get warned about something similar to:

Update links

Please answer Disable; the Excel Unit Operation will fix the links immediately after loading the workbook.

Once a fixed workbook is stored, the messages will no longer appear.

The Excel CAPE-OPEN unit operation was developed by AmsterCHEM.

Micosoft Excel and VBA are registered trademarks of Microsoft Corporation in the United States and other countries.

aggregation state
available properties
compound names
unit of measure
compound constants
control sheet
defined phases
equilibrium calculations
Excel solver
Export Model
flash calculations
getting started
Import Model
input parameters
Loading and storing models
output parameters
overall properties
pressure dependent properties
property calculations
quick reference
run-time error
single phase properties
state of aggregation
temperature dependent properties
thermodynamic equilibrium calculations
thermodynamic property calculations
two-phase properties
unit operation name
Update links
 Ports and streams
 Function reference
 The control sheet
 Using the Excel solver
 Using Macros
 Loading and storing models
 Persistence in AspenPlus