Contents

• Overview
• Scenario 1: Relative solubility in a synthetic brine.
• Scenario 2: Relative Solubtility under Geological Conditions
  • Updating the Existing Chemsity Model
  • Importing the new model into Aspen PLUS
    • Old Model Cleanup
    • Importing the Model
• Scenario 3: Removing a species from the chemistry model
  • Creating the new model
  • Importing and updating the Aspen Chemistry Model
    • OLD Model Cleanup
    • Removing Unwanted Components
    • Importing the model
    • Additional File Cleanup before running
      

Overview

It has been asked many times, "Can you have more than one model in Aspen PLUS OLI?" The short answer is yes, you can. You can have multiple models incorporating both Aspen PLUS chemistries and OLI chemistries. The only requirement is that the blocks using the OLI property set be able to recognize the component entering the block.

We will make some assumptions for this tutorial. The basic assumption is that you understand how to access Aspen PLUS and run that program. We also assume that you can generate OLI chemistry models using either the OLI Chemistry Wizard or the OLI Chemistry Generator.

The Example Case

In this example case, our user wants to determine the relative solubility of calcium carbonate in a synthetic brine. Initially the user wants to consider the solubility under process conditions. Secondly the user wants to consider the solubility under geological conditions. Finally the user wants to remove a species from the chemistry model.

To do this, the user has used the OLI Chemistry Wizard and created three models and two BKP files. See the Getting Started with Aspen PLUS OLI tutorial for an overview on how this is accomplished.

Scenario 1: Relative solubility in a synthetic brine.

Use of the OLI Chemistry Wizard has been described elsewhere (see OLI Chemistry Wizard). For this example we are going to use the following chemistry:

Temperature	25 C
Pressure	1 Atmosphere
H2O	50 mole/hr
CO2	0.01 mole/hr
CaCl2	1.0 mole/hr
SrCl2	0.1 mole/hr
MgCl2	1.0 mole/hr
CaCO3	0.01 mole/hr

A FLASH2 block was used and set to isothermal conditions, the same as the stream. Here is a picture of the process:

Stream 1:

Block 1:

Here are the results

Stream 3: Liquid Stream

You can see that CaCO3-S (solid calcium carbonate is 5.7E-04 moles and we used 0.01 moles initially for a relative solubtilty of 0.01 - 0.00057 = 0.00943 moles.

Scenario 2: Relative Solubtility under Geological Conditions

Now the user wishes to simulate the same input stream under geological formation conditions. This means we will use the OLI Geochemical databank. We have created a new OLI model for use in Aspen Plus called MODEL2. This model has the same input species but different phases. We will now create this new model.

Updating the Existing Chemsity Model

Enter the name of the new model or open an existing model. We manually copied the MODEL1.CWA file to MODEL2.CWA using Microsoft's File Explorer.

We will now activate the Geochemical private databank. Highlight the desired databank and click the right arrow.

This moves the database to the selected column.

Click Next to continute. From here, the steps are the same as with a standard OLI Chemistry Wizard model generation.

If you copied the model from a saved model, then the orginal selected components should be displayed. If not, add them here. Click Next when done.

We are not adding any redox chemistry or hydrocarbon pseudocomponents. Click Next to continue.

We are not modifying the phase selections. Notice that a new species "Aragonite" has appeared. This is also CaCO3 but in a different cyrstal morphology. Click Next to continue.

Update the Aspen Component ID and Alias if required.

If you are updating an existing chemistry model Be Careful! By default we will create a BKP file with the same name of the chemistry model. If this was your original BKP file, it will be overwritten and your process lost. Enter a new name here to avoid this issue. Since our original BKP file was called MODEL1, we are avoiding this problem.

Finish generating the chemistry model.

The files have been updated.

 

Importing into Aspen PLUS

Before we import the updated chemisry model into Aspen PLUS we need to remove the original model. Note: If we are adding a model (as a second model) then this step is not required.

Old Model Cleanup

First select Data from the tools menu. Then select Setup

This will display the setup options in the Data Browser. Close the Setup tree and open the Properties | Parameters | Pure Compnent tree.

In our example, "MODEL1" was the name of the original OLI model. In the right-hand window click the small box to the left of MODEL1. Then select the Delete button.

This will delete the model "MODEL1" from the component paragraph in the process flowsheet. You will be asked to confirm the deletion. Select Yes.

Next open the Reactions | Chemistry tree.

As before, select MODEL1 and click the Delete button.

Confirm the deletion by clicking Yes

Importing the Model

We are now ready to import the new OLI chemistry model. Select File from the menu.

Now select Import...

Locate the new BKP file created when you created the new OLI Chemistry Model. In our example, this file is MODEL2.BKP. Please note that this BKP file and the associated DBS file must be in the same folder the current BKP file.

You will asked to resolve the ID conflicts.

Select all the components and properties (scroll to the bottom) and click the Replace button.

The component ID's have been replaced. Click the OK button.

You will be asked if you want to keep the existing Aspen PLUS databanks. Since we are using the OLI thermodynamic databases, either choice is acceptable.

Rerun the calcuation and see how the output changed.

Substream: MIXED
Mole Flow   mol/hr
H2O	49.99247
CO2	2.47E-03
HCL	2.12E-11
CACL2	1.23E-17
CACO3	2.65E-07
MGCO3	3.04E-07
SRCL2	0
CA2CL2O	0
CA2CL2W2	0
CACL2W1	0
CACL2W2	0
CACL2W4	0
CACL2W6	0
CAHCO32	0
CABCACAR	0
CAHCO3CL	0
CABCABCA	0
CAHCO3OH	0
CAMG2CL6	0
CAO	0
CAOH2	0
CAOHCLIN	0
H2CO3IN	0
MGCL2	0
MGCA2CL6	0
MGCL2W2	0
MGCL2W4	0
MGCL2W6	0
MGCL2CO3	0
MGCLHCO3	0
MGCLOH	0
MGCO3W3	0
MGHCO32I	0
MGBCCARB	0
MGHCO3CL	0
MGHCO32	0
MGHCO3OH	0
MGO	0
MGOH2	0
SRCL2W1	0
SRCL2W2	0
SRCL2W6	0
SRCO3	0
SRHCO3	0
SRO	0
SROH2	0
SROH2W1	0
SROH2W8	0
CACL2-S	0
CACO3-S	0
CAOH2-S	0
MGCL2-S	0
MGCLOH-S	0
MGCO3-S	0
MGOH2-S	0
SRCL2-S	0
SRCO3-S	0
SRHCO3-S	0
SROH2-S	0
OH-	1.46E-09
CAHCO3+	1.03E-03
CA+2	1.007622
CAOH+	6.24E-09
CL-	4.199888
CO3-2	2.11E-08
HCO3-	2.86E-04
H+	6.29E-06
MGHCO3+	0.013742
MG+2	0.98502
MGOH+	1.52E-07
CACL+	1.12E-04
SR+2	0.1
SROH+	2.83E-10
ARAGON	0
CAMG3C	0
DISDOL	0
DOLOMT	0
HMAGNE	0
MG2HD2CT	0
MGHDCTW3	0
ORDDOL	0
ARAGON-S	0
CAMG3C-S	0
CAO-S	0
DISDOL-S	0
DOLOMT-S	0
HMAGNE-S	0
MGO-S	0
ORDDOL-S	1.24E-03
Total Flow  mol/hr	56.30388
Total Flow  kg/hr	1.124256
Total Flow  l/min	0.015928
Temperature C	25
Pressure    atm	1
Vapor Frac	0
Liquid Frac	0.999978
Solid Frac	2.20E-05
Enthalpy    cal/mol	-68163.1
Enthalpy    cal/gm	-3413.68
Enthalpy    kcal/hr	-3837.84
Entropy     cal/mol-K	14.27448
Entropy     cal/gm-K	0.714881
Density     mol/cc	0.058916
Density     gm/cc	1.176404
Average MW	19.96764
Liq Vol 60F l/min	0.015602
*** LIQUID PHASE ***
PH	4.870288

Notice that there is a new solid, ORDDOL-S which is ordered dolomite: CaMg(CO3)2. If you are comparing to Scenario 1 you will notice that the relative solubility is 0.01 moles - 0.00124 moles = 0.00876 moles (down from 0.00943 moles - the relative solubility decreased).

Scenario 3: Removing a species from the chemistry model

In this scenario, the user not only wants to remove the species SrCl2 from the stream, the species must also be removed from the model. This is done frequently to reduce the size of the model which, in turn, will increase the speed of execution.

Creating the new model

For this model, we will copy the existing model to a new name - MODEL3. We will also remove the GeoChemical databank and create the chemistry model as we have done in the previous examples. Here is the updated screen for removing the component.

Click the Remove Button and generate as in previous examples.

Importing and updating the Aspen Chemistry Model

We will follow the same steps as in Scenario 2 but there will be some additional deletions before we import the model.

Old Model Cleanup

As before we are removing the old model. Here are the steps

Removing the Pure Component Data

Removing the Chemistry Paragraph

Removing the unwanted components

The species Strontium Chloride (SrCl2) is not wanted in the simulation. After removing the OLI portion we now need to remove the Aspen PLUS portion.

Expand the Components Tree. Locate SRCL2 and select the row.

Right-click the selected row and select Delete Row.

This removed the component SRCL2 from the simulation. Unfortunately we also need to remove all the other strontium (Sr) containing components. Sroll down the list to find them. Here are a few more. You can select multiple rows.

Right-click the selection and select Delete Rows.

Continue to scroll down and remove all the SR containing materials. Be vigilant, some components will contain SR but it will not be apparent by the name.

Importing the model

We will now import MODEL3 (in our example). The steps are nearly the same as before: Select File | Import

Locate the corresponding BKP file to the new model. In this case MODEL3.BKP

Select all the ID's and click the Replace button.

Click OK

Keep the existing databanks.

Additional File Cleanup before running

With the deletion of the strontium species we have left holes in the data structure. We need to clean them up. Open the data Browser via the Data Menu and look for al the error circles. These tend to occur in the Parameters | Pure Component section. In our example both CPIG-1 and PLXANT-1 have errors.

Select CPIG-1.

The error is usually a blank component ID with data present in the column. Scroll the window to the right to locate a blank column. In the example there are three displayed (but there are many more).

Highlight a column and then Right-Click. Select Delete Column. You may select more than one column at a time. Becareful not to delete a column that contains a comonent.

Repeat the process for all invalid columns. When you are done, Aspen PLUS updates with a blue check mark. Now move on to the next parameter and repeat the same steps to remove blank columns.

When all the columns are removed the blue check mark appears.

You can now run the process. You can see that all the Strontium species have been removed.

Substream: MIXED
Mole Flow   mol/hr
H2O	49.99065
CO2	6.49E-04
HCL	3.77E-12
CACL2	9.85E-18
CACO3	1.87E-06
MGCO3	2.08E-06
CA2CL2O	0
CA2CL2W2	0
CACL2W1	0
CACL2W2	0
CACL2W4	0
CACL2W6	0
CAHCO32	0
CABCACAR	0
CAHCO3CL	0
CABCABCA	0
CAHCO3OH	0
CAMG2CL6	0
CAO	0
CAOH2	0
CAOHCLIN	0
H2CO3IN	0
MGCL2	0
MGCA2CL6	0
MGCL2W2	0
MGCL2W4	0
MGCL2W6	0
MGCL2CO3	0
MGCLHCO3	0
MGCLOH	0
MGCO3W3	0
MGHCO32I	0
MGBCCARB	0
MGHCO3CL	0
MGHCO32	0
MGHCO3OH	0
MGO	0
MGOH2	0
CACL2-S	0
CACO3-S	6.45E-04
CAOH2-S	0
MGCL2-S	0
MGCLOH-S	0
MGCO3-S	0
MGOH2-S	0
OH-	7.90E-09
CAHCO3+	1.31E-03
CA+2	1.01E+00
CAOH+	3.18E-08
CL-	4.00E+00
CO3-2	1.50E-07
HCO3-	3.92E-04
H+	1.24E-06
MGHCO3+	1.70E-02
MG+2	9.83E-01
MGOH+	7.49E-07
CACL+	9.70E-05
ARAGON	0
CAMG3C	0
DISDOL	0
DOLOMT	0
HMAGNE	0
MG2HD2CT	0
MGHDCTW3	0
ORDDOL	0
ARAGON-S	0
CAMG3C-S	0
CAO-S	0
DISDOL-S	0
DOLOMT-S	0
HMAGNE-S	0
MGO-S	0
ORDDOL-S	0
Total Flow  mol/hr	56.00159
Total Flow  kg/hr	1.108403
Total Flow  l/min	0.015875
Temperature C	25
Pressure    atm	1
Vapor Frac	0
Liquid Frac	0.999989
Solid Frac	1.15E-05
Enthalpy    cal/mol	-6.82E+04
Enthalpy    cal/gm	-3443.68
Enthalpy    kcal/hr	-3816.99
Entropy     cal/mol-K	14.35812
Entropy     cal/gm-K	0.725438
Density     mol/cc	0.058793
Density     gm/cc	1.163643
Average MW	19.79235
Liq Vol 60F l/min	0.015575
*** LIQUID PHASE ***
PH	5.601825

 

 

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