Overview

Infrequently, OLI will rename a species. While this is not usually a problem in the stand-alone OLI software, it can cause problems in our alliance partner software. In this case, OLI previously had a piperazine component in our AQ thermodynamic framework. The OLI Tag name was "PIPERAZINE," which is the name we would find in UniSim® Design.

Disclaimer: The examples here used UniSim®Design version R510 and OLI Engine versions 11.0 and 12.0

Video Tutorial

Video Text

Hi, today's video is about replacing a component from the OLI electrolyte model with an existing component already available in UniSim Design.

Let's consider a scenario that occurred in this particular case. I have a case here that is quite simple. You can see a basic stream, and if I expose its composition, you'll notice that it contains water, carbon dioxide, and piperazine. We have the following mole fraction concentrations: 95 mole% water, 1% carbon dioxide, and 5% piperazine.

In a later version of the software, specifically version 11 of the OLI Engine and version R510 of UniSim Design, OLI changed the name of piperazine. The reason for this change is unclear, but it does present a problem. As you can see, the current simulation runs smoothly and has successfully converged.

Let's navigate to the basis environment and check our fluid package. In the trace window, we can view the electrolytes listed here. You'll notice piperazine appears multiple times in this list. However, since the name has been changed in a later version, we will need to open it. I will close the current version without saving and then reopen it.

We're reopening version R510, but this time using the new OLI Engine. I have already configured the tool within the software. Additional videos on this process are available in our knowledge base. Now, R510 is linked to version 11 of the OLI Engine, and I will link it to version 12. That's all that needs to be done here. Now, I will start the software.

After opening the same case as before, you'll see some error messages in the trace window. According to the error dialog, the initialization of the OLI Electrolyte property package failed. Let's take a look at the trace window. It indicates that piperazine is no longer available. Why? Because OLI renamed piperazine. Again, the reason for this is unclear, but it certainly poses a challenge.

Let's explore our fluid package and examine the components. Here’s piperazine. I know that OLI renamed it PIP. However, when I search for PIP in the OLI data books, I don’t see anything that starts with those letters, but I know it is there.

To facilitate the quick generation of that list, OLI employs indexing values. Some index files on your computer will need to be temporarily deleted so they can be rebuilt. I have the file folder open; it will be located in your Documents folder under UniSim Design, within the version number you are interested in, and finally in a User folder: \Documents\Unisim Design R510\User\

You’ll find two files: OLI ADB (AQUEOUS Database) and OLI MDB (MSE Database). These should be deleted; they will be rebuilt dynamically. Please do not delete the console IDX file.

Let’s restart UniSim Design. I will reload the same case as before. As you can see, I still encounter the same error message. The difference now is that I can view the component when I go into the fluid package. I want to check the electrolyte, and there it is—PIP. This is the same species that was renamed from piperazine, which I had previously.

I will click the substitute button, and it should be quick. Now, I can initialize the electrolyte environment. I should have cleared my error messages, and that is done. I will proceed to build the model, and you can see that all instances of piperazine have reverted to PIP.

If I go into the case selection, we’ve been left in a holding state since we returned from the fluid package. If I click on Stream 1 and go back to compositions, you'll remember that piperazine had a mole fraction of 0.05, or 5 mole percent, and it has been renamed.

This is a quick way to reintegrate the same values for that component. If I run the simulation, it executes successfully. We can retrieve our electrolyte values as we would expect to see in the OLI model.

We will save this as a new name in the folder we were working in. Let’s call it... and that's it! We’re done. Thank you very much.

Conclusion

When OLI renames a species within its thermodynamic framework, it can create temporary inconsistencies in integrated simulation environments such as UniSim® Design. While these changes are infrequent, they are part of OLI’s ongoing efforts to refine data accuracy and maintain internal consistency across versions. For users, the key is understanding how to recognize the renamed component, reset indexing files appropriately, and apply substitution tools within UniSim Design to restore functionality without compromising model integrity.

This process, though technical, is straightforward once familiarized. By following the outlined steps (verifying fluid packages, clearing outdated local databases, and leveraging UniSim’s substitution features), engineers can confidently re-establish reliable simulations. These capabilities reflect the robustness and adaptability of OLI’s software ecosystem, ensuring continued alignment with evolving chemical models while maintaining the operational continuity critical to industrial users.