Process Solutions
Product Information Note
UniSim® Design -OLI Electrolytes Option
Predicting the behavior of Electrolyte Systems within UniSim
Design
The oil and gas production, gas processing, petroleum refining and chemicals
industries take advantage of this option to model their electrolyte processes, achieving
more reliable and stable designs and operations.
A process cannot be designed and optimized effectively without
process economics, reliability, versatility, and meets
comprehensively and accurately addressing the chemistry and
environmental constraints.
thermodynamics phenomena. This is especially true for
The Challenge
electrolyte systems, where chemistry is particularly complex and
When simulating an Electrolytic System, a process engineer is
challenging to understand and predict, for those real industrial
concerned about several areas. As an example, consider a
systems containing many components and operating over broad
process application in which chlorine, a component of an off-gas
ranges of temperatures, pressures, and concentrations.
product, is to be scrubbed with (10% by weight) sodium
These processes may include:
hydroxide solution.

Aqueous/Mixed Solvent chemical and separations processes.
To increase scrubber efficiency, plant operators increased the

Chemical conversion.

Solution crystallization.

Reactive separations including acid gas treatment.

Waste water treatment.

Environmental behavior of wastes, discharges, and accidental
sodium hydroxide concentration from 10% (by weight) to 20% (by
releases.
weight). In addition, the Waste Liquid from the scrubber was
desired to have a pH > 8.3 for alkalinity control. The result of the
change in concentration resulted in frequent fouling of the
scrubber and an inability to control the pH.
Plant operators noticed that the column fouled frequently at the
high concentrations of sodium hydroxide, and that the off-gas
contained carbon dioxide as well as chlorine.

Corrosion and scaling of equipment.
The challenge is to provide a solution allowing engineers to

PFD (Process Flowsheet Diagram) Modelling Environment
quickly define electrolyte systems and study the impact they will
have in the overall production process.
Simplified electrolyte system modeling and computational
approaches using approximation are usually ineffective, and can
To improve the engineering workflow and support the impact
be potentially dangerous, when applied to real process
studies, the required solution shall seamless integrate within the
applications. Electrolyte systems often behave in complex and
general process simulation environment, by predicting
unpredictable ways, introducing great risk into plant design and
thermodynamics and physical properties, for aqueous and mixed
operation if they are not adequately understood and accounted
solvents.
for. On the other hand, reliable electrolyte models can ultimately
The Solution: UniSim OLI Electrolyte Option
provide tremendous insight, process alternatives, efficiencies in
UniSim Design Suite helps process industries improve
plant design, trouble-shooting, and optimization. This improves
productivity and profitability throughout the plant lifecycle. The
UniSim® Design Link to Pro-M
2
powerful simulation and analysis tools, real-time applications and
equation of state and parameter regression and proprietary
the integrated approach to engineering solutions provided by
estimation techniques, the OLI model provides accurate
UniSim Design Suite enables companies to improve designs,
equilibrium constants and other standard state properties over
optimize production and enhance decision-making.
the broadest possible aqueous range of conditions.
UniSim Electrolyte Option is based on technology developed by
Activity coefficients for complex, high ionic strength
OLI Systems Inc., experts in aqueous chemistry. It enables
systems. Based on the combined work of Bromley, Zemaitis,
analysis of complex aqueous electrolyte systems within UniSim
Meissner, Pitzer, and OLI technologists, OLI models can predict
Design by combining the Honeywell’s simulation power with the
behaviour under real world conditions.
extensive OLI’s databank and thermo-physical properties for
more than 3,000 organic and inorganic electrolytic species. It
offers OLI’s new Mixed Solvent Electrolyte model, allowing the
simulation of strong electrolyte systems and systems that
combine electrolytes with non-electrolytes. UniSim Design also
Comprehensive databank. The Databank covers 79 inorganic
elements and their associated compounds and complexes, and
over 3000 organic chemicals. For customized coverage of clients'
chemistry and private databanks, contact OLI Data Service.
has the capability to handle user-specified hypothetical
Thermo-physical properties. OLI has developed unique
components in the OLI simulation environment, expanding its
chemical-physical based models to compute thermodynamic and
reach to refinery applications.
transport properties for complex aqueous/mixed solvent
In the example considered before, by using the UniSim OLI
Electrolyte Option, operators found that sodium bicarbonate was
created when the sodium hydroxide concentrations was
environments and are provided by the UniSim OLI Electrolytes
Option. This unique and powerful electrolyte capability provides
benefits in profitability through a host of applications in the oil and
gas, chemicals, government research, pulp & paper, metals and
increased. Indeed; at 20% by weight concentration of sodium
hydroxide, sodium bicarbonate (a solid) begins to form. The plant
mining, pharmaceutical, petroleum, and energy industries as has
been the case of past OLI clients.
operators confirmed the presence of this solid in their scrubber.
Benefits
The UniSim OLI Electrolytes Option allows you to access OLI
components and the OLI Engine, which is distinguished by the
following unique elements:
Complete speciation. The OLI model predicts and considers all
of the true species in a solution, and accounts for these in the
computations.
Robust standard state framework. Based on the Helgeson
For More Information
Learn more about how Honeywell’s UniSim
Design can improve your process performance
visit our website www.honeywellprocess.com or
contact your Honeywell account manager.
Honeywell Process Solutions
Honeywell
1250 West Sam Houston Parkway South
Houston, TX 77042
Honeywell House, Arlington Business Park
Bracknell, Berkshire, England RG12 1EB
Shanghai City Centre, 100 zunyi Road
Shanghai, China 200051
www.honeywellprocess.com
PN-15-18-ENG
March 2015
© 2015 Honeywell International Inc.
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