Objective
This article provides a step-by-step guide for first-time users on how to utilize the OLI Chemistry Wizard to create the model files that can be integrated into various OLI applications, including OLI Regression, OLI Alliance products, OLI Engine API, OLI Corrosion API, and OLI ScaleChem API.
Disclaimer: The user interface, calculations, and results displayed in this article are from OLI Chemistry Wizard Version 12.0. Other software versions may appear different due to continual developments to the software.
When Should You Use the OLI Chemistry Wizard?
Launching OLI Chemistry Wizard
Step 4. Redox, Assay, and Pseudo Component Selection
Example with Redox, Assays, and Pseudo Components
When Should You Use the OLI Chemistry Wizard?
The OLI Chemistry Wizard is essential for generating model files that are used by OLI Alliance products and for performing regression analysis on private databases.
Typically, the OLI Regression workflow is as follows:
- Data Collection: Gather data from literature or experiments for your species of interest.
- Database Creation: Create a private database using OLI Databook.
- Model Generation: Use OLI Chemistry Wizard to generate model files for the species in your private database.
- Input File Preparation: Prepare regression input (.inr) files using a text editor.
- Run Regression: Execute the regression case in the OLI Regression Console.
- Iterate: Repeat steps 4-5 until the regressed output parameters meet your convergence satisfaction.
- Update Database: Update your private database in OLI Databook with the new regressed parameters.
While regression is a common use-case for OLI Chemistry Wizard, the generated model files can also be used with OLI Alliance products, OLI Engine API, OLI Corrosion API, and OLI ScaleChem API.
Launching OLI Chemistry Wizard
To start the Chemistry Wizard:
- Double-click the application icon on your desktop, or
- Navigate to: Start > All apps > OLI Regression > OLI Chemistry Wizard 12.0 for Regression
Step 1. Welcome Dialog
Upon launching, you will see the Welcome dialog, where you can:
- Specify a model name: Enter a name (no extension) for your model.
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Choose a save location: Select the folder to which you would like Chemistry Wizard to save the generated files.
- The program will default to a certain path, which can be adjusted with the Browse button. The Reset button will re-assign the default directory.
If you need to revisit an existing model, select Open Existing Model and choose from the available file types:
- OLI Chemistry Wizard Files (.cws) {Note: For Aspen Plus this file extension is .cwa}
- OLI Chemistry Model Files (.mod)
- OLI Chemistry Dbs Files (.dbs)
This allows you to return to a case you created in Chemistry Wizard, make revisions, and regenerate model files.
After you supply a model name, the Next button will activate. Click Next to proceed.
Step 2. Databanks
By default, the Chemistry Wizard will select MSE as the thermodynamic framework and its corresponding database.
- This means only private databases built on the MSE thermodynamic framework will be listed as Available.
- The user can switch the thermodynamic framework to AQ or MSE-SRK as needed.
- A private database can be selected from the Available list. Click the right arrow to move it to the Selected list.
- When 2 or more optional databanks are added to the Selected list, they can be re-sorted using the up and down arrows. The databanks are searched from top to bottom, with the baseline databank (MSE, MSE-SRK, or AQ) searched last.
In the example below, we have selected a private database, though this is not a requirement.
If you are searching for a private database that is not displayed in the Available list, you may need to adjust the file paths in Databank Preferences.
The Private databanks location is set by default by the system. However, you can change this with the Browse button > change file path > select OK > close Chemistry Wizard > re-open Chemistry Wizard > repeat the steps above.
The baseline OLI Systems-provided databanks (MSE, MSE-SRK, AQ) are stored in the Directory Path. It is strongly recommended that you do not change these settings.
When you are ready, please click Next.
Step 3. Component Selection
Here, you will see the components selected for your model. By default, water is always included.
- Add components: Click the Add button to search and select additional components by ID, Formula, or Name. The column being searched has a plum-colored arrow pointing up (ascending sort order) or down (descending sort order).
- Sort components: Components can be sorted by ID, Formula, or Name.
In this example, we will add NaCl, HCl, and NaOH:
- Type NaCl in the Search by ID field. If you press the Enter key or click the Add button, the highlighted species will be added to your list of selected components.
- Type HCl and press Enter.
- Type NaOH and press Enter.
- Now, close the dialog by clicking the Close button.
Note: We have not selected any components from the private database, but the same process would apply.
Your Selected Components page should now look like this:
Click Next to proceed.
Step 4. Redox, Assay, and Pseudo Component Selection
This dialog allows you to include reduction/oxidation (Redox) chemistry, assays, and pseudo components in your model. For now, we will skip these options, but they are reviewed later in this tutorial.
Click Next to proceed.
Step 5. Phase Selection
Select the phases to include in the equilibrium calculations:
- Default Phases: Aqueous, Vapor, and Solids.
- Optional Phase: Enable the Second Liquid phase if your model includes organic species.
- Inert Solids: You can specify the density and heat capacity of non-reactive components like ash or coal.
You can choose to exclude specific solid species that would otherwise be automatically loaded into your chemistry model. This helps to limit the size of your chemistry model and improves equilibrium calculation performance. We suggest that you include all solids until you are sure that you can safely ignore any in the temperature, pressure, and concentration region of interest.
Click Next to proceed.
Step 6. Summary
The Summary page displays all your selections.
If you click the Generate Files Now button, all the chemistry model files will be created in the background without leaving the application.
- It is also possible to return to previous pages, make changes, and regenerate model files.
- If your model files are generated successfully, the following dialog will appear:
When you click OK on this pop-up, followed by the Finish button, the files will be saved locally and the application will be closed.
The pop-up window indicated the folder to which the chemistry model files were written. The following files should now appear in your working directory:
These are each ASCII files that can be opened using a text editor such as Notepad.
Example with Redox, Assays, and Pseudo Components
Redox
If you would like to consider Redox chemistry in your simulations, you will need to enable the Enable Redox checkbox.
In Included Subsystems, click on the subsystems you would like to consider. In this example, we will consider some oxidation states for chlorine.
- Note: Redox will dramatically increase the number of components involved in the simulation and will impact calculation times. Be selective to minimize impact on calculation times.
Assay
An Assay can be added by clicking on the Add button in the dialog and selecting Assay.
You can define the assay by specifying the distillation data, average bulk density, and the number of cuts.
- The Distillation Data grid allows you to enter ordered pairs of distillation volume and temperature values. Rows can be inserted or deleted by right-clicking on the lefthand box next to a row in the grid.
Once all the data has been entered, you can click Calculate to view the list of components and their physical properties generated by Chemistry Wizard.
Click OK to save the assay definition.
Pseudo Components
Similarly, pseudo components can be added by selecting Add > Pseudo Component.
In the Pseudo Component Entry dialog, you can enter parameters such as normal boiling point, specific gravity, and molecular weight.
Click on Calculate to view the generated properties. Click OK to save the definition.
Conclusion
This article has provided a comprehensive guide to generating chemistry model files using the OLI Chemistry Wizard. These files are necessary for integrating OLI’s advanced chemistry models into simulations with Alliance products, OLI Cloud products, or for conducting regression analyses.