MSE model 

The Mixed Solvent Electrolyte (MSE) model is OLI's newer model which has removed both the concentration limit and the presence of water as limits to OLI simulation capability.  

The MSE model has about half of the species of the OLI AQ databank and in addition, it contains many chemistries that cannot be simulated in the AQ model because they are beyond the AQ model's capability. Highlights include lithium and potash chemistry and sulfuric acid for the metals and mining industry, the amines, alcohols and glycols (with hydrocarbons for oil and gas), and arsenic, mercury, and many other chemistries of interest to the industrial water treatment industry.

OLI recommends the MSE model when your chemistry of interest is available in this model. Ask us if you are not sure!

AQ model

The Aqueous (AQ) model is OLI's original electrolyte thermodynamic framework. A fully speciated model with coverage of 80+ elements of the periodic table, for systems -50 to 300 C, 0 to 1500 bar, and up to 30 molal ionic strength. This is suitable for heavy brines, brackish water, slurries: anywhere where water ( H2O ) is dominant.  This model assumes the presence of water.



  • Solution thermodynamics

  • Thermodynamics of corrosion

  • Kinetics of generalized corrosion

  • Localized corrosion

  • EVS

OLI's applied R & D into the science of corrosion began in 1995, building on the first step in understanding aqueous corrosion: the solution thermodynamics. OLI then added models for the thermodynamics of corrosion through the facility of Pourbaix Diagrams; a model for the kinetics of generalized corrosion by generating Polarization curves and also the partial anodic and cathodic processes that develop; a model for localized corrosion by calculation of corrosion potential versus repassivation potential, and a statistical model for calculating remaining asset life given pit depth versus time information.  


OLI as a property method

OLI's range of applicability extends to multi-stage calculations and also multi-unit processes with recirculation. When you are using a commercial flowsheet simulator and would like to include OLI as a property method, you can! OLI is available as a property method in several flowsheet simulators by using one of OLI's Alliance Partner products.

Electrolyte flowsheet simulation

OLI Flowsheet: ESP is OLI's electrolyte flowsheet simulator for heat and material balance calculations, including multi-stage columns and recycle. Designed especially for industrial waste water treatment, OLI Flowsheet: ESP is a unique software that contains environmental blocks such as membranes and neutralizers as well as the standard operations and controllers founded in other flowsheet simulators.

OLI's mineral scale prediction for the upstream has become the industry standard for scale analysis in new and existing assets. OLI's electrolyte thermodynamic framework offered a solid beginning. Building on the framework throughout the years, OLI has partnered with industry specialiists in oil and gas companies who have specified the requirements for state-of-the-art, specialized upstream calculations. 


In 2016, OLI partnered with Scaled Solutions and AQSim to sponsor the UltraHPHT consortium. UltraHPHT was a project that combines experimental work and modeling work, in order to increase the accuracy of OLI simulations for the extremely high pressure / high temperatures of production environments today. Some of this work is generally available as of V9.6 in HPHT improvements to PbS, ZnS, and CaSO4. Other improvements to CaCO3 and BaSO4 will be available at the end of 2018.

OLI for pipeline calculations

OLI can calculate scale appearance and disappearance lines within a pipeline, rigorously predicting scale behavior of fluids in pipelines. This is possible by partnering with Schlumberger and using the joint capabilities of OLI electrolyte thermodynamic model and Schlumberger's fluid flow model.