OLI Mixed-Solvent Electrolytes

FAQ

What is the objective of the model?
How was the model funded?
Why develop a new model?
What type of model is it?
What are the advantages of a true speciation model?
Is the MSE model based on OLI's prior model?
How accurate is the model?
What are the applications of MSE?
When will MSE be available?

This graph is the experimental vs calculated (in OLI MSE) solubility of solids in solvents ranging from pure water to pure acid for the system
(NH4)2(SO4)+H2SO4+H2O------>

What is the objective of the model?

The objective of OLI's mixed solvent electrolyte (MSE) model is to produce a model capable of reproducing speciation, chemical, and phase equilibria, applicable to water-organic-salt systems in the full range of concentrations as well as aqueous electrolytes from dilute solutions to the fused salt limit. This objective has now been achieved. return to top

How was the model funded?

The development of this MSE model was partly funded by $500K from the US Department of Energy. Industry partners formed a consortia which supplied additional funding. The consortium members include Chevron, Dow, Mitsubishi Chemical, Shell, Rohm & Haas, DuPont and Alcoa.

OLI has produced the most advanced, predictive framework for the prediction of electrolytes, aqueous as well as mixed solvent. With this model, known as the MSE Model, many chemical systems of industrial importance can be simulated from the perspective of process as well as corrosion applications.return to top

Why develop a new model?

We developed this model because there was no such comprehensive, speciation-based model, which could apply to both process and corrosion applications and leverage OLI's enormous prior effort with regard to implementation and databank for equilibrium constants via the Helgeson EOS.return to top

Which type of model is it?

Basically, there are three types of MSE models:

  • models that treat electrolytes on an undissociated basis;
  • models that treat electrolytes as completely dissociated; and,
  • models that deal with the true speciation.return to top

What are the advantages of a true speciation model?

Only the true speciation model will allow for prediction of properties such as pH, ORP, etc. Only this model will predict reasonably complex multicomponent systems. And, only this type of model will provide the information needed for prediction of electrochemical processes such as corrosion. return to top

Is the MSE model based on OLI's prior model?

The OLI model is able to utilize all prior work on the Helgeson EOS and supporting databank through a conversion of the standard-state chemical potentials provided for aqueous systems. This means that the equilibrium constants and other standard state partial molal thermodynamic properties are readily predicted for mixed solvent environments. The activity coefficient model is new and is based upon an extended Debye-Huckel term, a Uniquac term, and a middle-range electrolyte term. return to top

How accurate is the model?

The accuracy of the current model is illustrated via a number of figures available through OLI. return to top

What are the applications of MSE?

There are many important applications envisioned for this new technology. A number of the principal applications include:

* Sulfuric acid plants
* Urea plants
* Gas treating systems using alkanolamines
* Concentrated nitrate systems (nuclear waste storage and processing, fertilizer industry, etc.)
* Phase equilibria in refinery column overheads (precipitation and dissolution of NH4Cl and NH4HS)
* Battery electrolytes
* Crystallization from organic and mixed solvents
* Systems with concentrated brines as working fluids (completion fluids, refrigeration cycles, etc.)
* Hydrometallurgical processes (e.g., high pressure leaching)
* Systems involving glycols (gas dehydration, heat exchange)
* Gas hydrate inhibition in deep sea environments

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When will MSE be available?

OLI already uses MSE for its professional services consulting. Within the sofware, MSE is already implemented within the ESP Software. OLI has and can develop MSE databanks to support specific client process simulation applications. In 2004, OLI will further provide the MSE implementation to support the Analyzers, including CorrosionAnalyzer.