FactSage and the OLI Databank
The OLI Databank
OLI Systems, Inc. - founded in 1971 by Dr. Marshall Rafal - has developed commercial computer software and databases that simulate aqueous-based chemical systems and employ a predictive thermodynamic framework for calculating the physical and chemical properties of multi-phase, aqueous-based systems.
OLI provides a family of software simulation tools (for example StreamAnalyzer, CorrosionAnalyzer, WaterAnalyzer) that address a wide range of applications - from rates of corrosion, oil and gas well plugging, and wastewater treatment, to chemical processing plant operation and optimization, reactive separations, and environmental simulations.
The core data are stored in the OLI Databank (Public.ddb) that contains thermodynamic, transport, and physical properties for 79 inorganic elements (including actinides, heavy and precious metals) and their associated aqueous species. The databank also includes over 3000 organics (including electrolytes, chelates and organo-metallic species) applicable in the following ranges: temperature, -50 to 300 °C; pressure, 0 to 1500 bar; ionic strength, 0 to 30 molal. It also contains data for the non-ideal gas phase and for many pure solid precipitates. Thus many common mixtures of chemicals in water can be modeled.
FactSage Aqueous Databases
FactSage offers the following aqueous databases:
None of the FACT aqueous databases offer the species selection, temperature and pressure ranges that are available in the OLI Databank. Hence it was decided to develop a link between the FactSage and OLI software that would enable a FactSage user to import OLI aqueous data (possibly together with FACT, SGTE and other data) and employ them in Equilib calculations.
OLI StreamAnalyzer and FactSage Equilib
The OLI StreamAnalyzer (the software supplied by OLI) performs calculations similar to the FactSage Equilib module. For example with the StreamAnalyzer you can run
Survey Calculations - similar to tabular and graphical displays in Equilib and Results:
Following extensive FactSage program development we are pleased to report Equilib is now able to access the OLI Databank and perform many of the OLIStreamAnalyzer SinglePoint Calculations. At 25 °C the results are nearly identical or very similar - see Comparison of OLI StreamAnalyzer and FactSage Equilib Results later on.
In addition, one can also import FACT and SGTE data (solid compounds and real solutions) into the calculations and include them as possible products, although thermodynamic consistency with the OLI data can not be guaranteed. (At the present, when FACT and SGTE data are used only full redox equilibrium calculations can be performed.)
How FactSage Users Can Access the OLI Databanks
For FactSage to access the OLI databanks both FactSage and the OLI StreamAnalyzer must be installed on the same PC, and both software packages must be fully licensed and operational (i.e. not demonstration, setup or time expired versions).
In the case of FactSage it must be the current version (or update) that has been released within the previous 12 months - if it is more than 12 months old then the FactSage - OLI Databank link will no longer work. For example, in the case of FactSage 5.2 which was released in May 2003, the link will be OK until June 2004.
In addition you will need to install a security program supplied by us that will enable FactSage to access the OLI security key (dongle). Equilib should then be able to access the electrolyte data from the OLI Databanks and include them in the calculations. If your PC is connected to 2 dongles (one OLI dongle and one FactSage dongle) make sure the dongle for OLI is connected first (i.e. closest to the PC) - it works better that way.
Adding OLI Databanks to the FactSage List of Databases
In order to include the OLI databanks in
(Alternatively in the [Reactants Window] of Equilib click on ‘Data Search > Databases > File > Add ...’).
This opens the [Compound (or Solution) – list of databases Window] – for OLI Databanks compound and solution data are stored in the same file, so you can specify either Compound or Solution and it makes no difference since it is the same databank.
Click on ‘Browse’ to open the [Open Window]. At the bottom click on the ‘Files of type’ drop down menu and make sure ‘OLI Systems database (*.ddb)’ is selected.
Now locate the folder where the OLI databanks are stored (for example 'c:\Program Files\Oli\Databanks\'). Select ‘Public.ddb’ and click on ‘Open’ – this returns you to the [Compound – list of databases Window]. Now click on ‘OK’ to add this ‘OLIP’ databank to the list of databases. Since OLIP (i.e.Public.ddb) is the core of the OLI databanks it must be added first.
You can also add other OLI databanks such as:
Including/Excluding OLI Databanks in Calculations
(You can ignore this section if you are going to run the Sample Calculations using OLI Databanks - see next section.)
In order to include or exclude the OLI databanks in your Equilib calculations, click on the ‘Data Search > Databases > ... ’ menu bar at the top of the [Reactants Window].
This opens the [Databases Window] that that lists all databases. Click on the "+" column of OLIP in order to include the database in the data search. Repeat for OLIC, OLIG, OLIL etc. as required.
Sample Calculations using OLI Databanks
For these examples to work both FactSage 5.2 and the OLI StreamAnalyzer must be installed on the PC, and the OLIP (Public.ddb) databank must be in the list of databases (to see how this is done refer to an earlier section on Adding OLI Databanks to the FactSage List of Databases). However it is not necessary to Include OLI Databanks in Calculations as discussed in the previous section since the sample files automatically do this for you.
In the [Equilib Reactants Window] click on ‘File > Directories > OLI Systems Examples’ for sample calculations. These examples introduce the OLI Systems Databanks and show how to use Equilib to perform a variety of calculations (ex: NaCl solubility in water; water and benzene equilibrium; combined FACT and OLI database calculations, SGTE alloys in water).
Additional sample calculations are available - these include:
'H2O + 10 molal NH4Cl - phase transitions', 'Arsenic V acid with sodium hydroxide - an example of an aqueous poly-basic titration', 'Copper dissolution in aqueous ammonia - an example of partial redox', 'CuO + NH3 with (NH4)2SO4 - no redox', 'NiO + NH3 with (NH4)2SO4 in air - partial redox', 'PbCl2 in aqueous NaCl - an example of enhanced solubility by complex formation' 'Ni-Fe leaching in aqueous ammonia - a metallurgical example of partial redox with H2 formation suppressed', 'Aluminium hydroxide solution in pressurised aqueous NaOH - an example of the principles of the Bayer Process', 'Cyanidation of Au-Ag as an ideal solution alloy', 'AgCl + Pb in aqueous NaCl - example of cementation with partial redox and H2 formation suppressed', 'CdSO4 + Zn in aqueous solution - example of cementation with partial redox and H2 formation suppressed', 'Reduction of NiSO4 from aqueous NH3 solution by H2 - a metallurgical example with partial redox', 'Titration of iron II with dichromate - example of a redox titration with O2 formation suppressed', 'Activity of FACT Fe(s) vs OLI Fe(s) - effect of OLI's polynomial fit of Helgeson's solute model', 'Evaporation of sea water under air at 25 °C - example of sequential precipitation', etc.
Most of the OLI sample calculations have been prepared by Dr. Michael (Mike) W. Wadsley, Austherm Pty Ltd as part of the FACT Industrial Consortium Project. For more information Mike may be contacted by email at Wadsley@austherm.com.au.
Comparison of OLI StreamAnalyzer and FactSage Equilib Results
If you examine the above examples you will note that the StreamAnalyzer results are never identical to the Equilib results for the same calculation, even when accesssing the same database(s).
Generally, the StreamAnalyzer applies a Newton-Raphson iteration technique on the equilibrium constants (K-fit polynomials). The calculation is efficient but only applicable to aqueous-based systems up to 300 °C. On the other hand Equilib applies a general Gibbs energy minimization approach to the thermodynamic data (derived in part from the K-fit polynomials) for each compound and solution phase, and the aqueous phase is treated just like all the other phases. The calculation is much slower, but it is more general and not limited to aqueous-based systems.
At 25 °C the two sets of results should be in good agreement. However as temperatures increase the agreement may not be as satisfactory (due to an increasing inconsistency between the K-fits and the derived thermodynamic data), but nevertheless the difference between the sets of results should still be very acceptable. We believe that the calculated results between FactSage and OLI are equivalent when numerical accuracy and different values for primary constants are considered.
At 25 °C, data from the OLI databases should be in reasonable agreement with data on the pure solid species with the same chemical formula from FactSage databases since the original standard state data are often taken from the same source. The method OLI uses to calculate the thermodynamic properties of solids is that for low solubility solids, when the default calculation method is used, the calculated values are less accurate at temperatures below 25 °C and above 100 °C. That is, OLI solid precipitates are consistent with OLI aqueous data; FACT and SGTE solid precipitates may not be consistent with OLI aqueous data, especially at higher temperatures. It is suggested that if you are working at these conditions with low solubility FACT solids in the system, you activate the ‘Helgeson direct’ option. With this option active, calculation times will be significantly increased.
Also, unlike FactSage solid species, in Equilib precipitates from OLI databases can not be extrapolated outside their reported temperature ranges.
OLI Options in Equilib
When the OLI Databank is included in the Equilib calculation, the [Equilib Reactants Window] automatically displays the following OLI Options :
Restrictions on Equilib when accessing OLI Databanks
The list of restrictions will change as the FactSage-OLI interface is developed. Currently OLI Databanks can only be included in Equilib calculations. For example it is not possible to access the OLI Databanks through the View Data module.
The following is a partial list of restrictions on Equilib when OLI Databanks are included in the calculation.
Last updated: May 6, 2003 - Christopher W. Bale
~ page created by Eve Bélisle ~