Objective
This article explains when to use the Corrosion and Geochemical databases in your OLI simulations. These databases are automatically included with any OLI software license.
Disclaimer: The information provided in this article is from OLI Version 12.0. Other versions may have different species available due to continual developments to the databases.
Overview of Databases
Some simulations require additional databases beyond the standard system databases to provide specific predictions. Two specialty databases are Geochemical and Corrosion. To learn how to load a non-standard database into your OLI Studio and OLI Flowsheet: ESP simulations, please see this article.
Geochemical | Corrosion |
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When to Use the Geochemical Database
The important factor for determining whether to include the Geochemical database is time of equilibration. This typically applies if you need to answer the question:
Does a species form only over a long time period, such as a geological timeframe?
Example:
- SiO₂ (Amorphous) is present in the standard MSE database. However, SiO₂ (Quartz) is only available in GEMSE.
- Under typical process conditions, we expect only amorphous SiO₂. But when a geological timeframe is relevant, quartz should also be considered, which requires the Geochemical database.
When to Use the Corrosion Database
The important factors for determining whether to include the Corrosion database are:
- time of equilibration for aging processes
- the presence of metal surface species
Below, we will review an illustrative example.
- Under typical process conditions, Fe(OH)₃ can form. For this reason, Fe(OH)₃ exists in the standard OLI databases for AQ and MSE.
- However, species like Fe₃O₄ and FeO(OH) form as protective films on corroding metal surfaces. For this reason, Fe₃O₄ is incorporated into CORROSIO.ddb (and already exists in MSEPUB.ddb), and FeO(OH) is incorporated into CORROSIO.ddb and CRMSE.ddb.
- Additionally, Fe₂O₃ forms from the aging of Fe(OH)₃, either on the surface or in the bulk. To simulate this, the CORROSIO.ddb or CRMSE.ddb databanks are required.
To determine the list of components in specific databanks or frameworks, please see our article on how to use the OLI Data Locator application.
Conclusion
In summary, the Geochemical database should be used for long-term processes where geological timescales are significant, while the Corrosion database is essential when simulating corrosion-related phenomena or reactions on metal surfaces.