How to Enable the OLI Library of Unit Operations in Aspen Plus®

Table of Contents

Overview

OLI has introduced two specialized electrolyte unit operations, EFLASH (4-phase flash) and FRACHEM (distillation tower), to Aspen Plus via the user-added blocks capability. These OLI blocks are integrated through the Customize tab under Manage Libraries, enabling advanced separation calculations directly within the Aspen Plus simulation environment.

A significant enhancement offered by the EFLASH is the ability to perform a true 4-phase separation, a feature not natively available in Aspen Plus. These operations support rigorous phase modeling essential for complex electrolyte systems, ensuring comprehensive thermodynamic representation and system fidelity.

Getting Started

1. Launch Aspen Plus as usual and open the .BKP file generated through the OLI Chemistry Wizard or OLI Chemistry Generator. For guidance on creating or importing a .BKP file, refer to:

   • How to import a new OLI chemistry model into an existing Aspen Plus® flowsheet – OLI Systems, Inc.

   • OLI Engine V12 in Aspen Plus® User Manual – OLI Systems, Inc.

1. Navigate to the Simulation/Flowsheet pane, then open the Customize tab and select Manage Libraries.
   
   
   
2. The OLI entry will appear if the OLI Option is licensed and the OLI Engine for Aspen Plus has been installed. Enable it by checking the box and closing the window.
   

3. If the OLI library is not listed, it must be imported:

   • Click Import…

   • Navigate to: C:\Program Files\AspenTech\AprSystem V14.0\GUI\Xeq

     • (Adjust the path based on your installed Aspen Plus version if different from V14.0.)
   • Select the olimod.apm library.
     

4. Once the library is added and activated, it will remain available for future use on that machine for the corresponding Aspen version.
   

5. Upon successful loading, the OLI block icons will be visible in the library toolbar of the Aspen Plus interface. The EFLASH (Eflash4) and FRACHEM (FraChem) units are accessible in the library palette and can be added to the flowsheet via drag-and-drop.
   

6. For a detailed walkthrough and example, consult the OLI Engine V12 in Aspen Plus® User Manual, starting on page 46.

Application Guidance: When to Use OLI UnitOp Blocks

• Use the Eflash4 block when you want to separate a system into four distinct phases: vapor, aqueous, organic/non-aqueous, and solid. This block enables complete phase resolution, essential for high-fidelity modeling of complex electrolyte systems.
• The FraChem and Eflash4 blocks are optimal for scenarios involving extreme differences in composition or other numerical magnitudes, such as values of the same component ranging from 1e-10 to 1e+20 in different stages or phases. It ensures more stable and accurate convergence during flash calculations under such conditions.
• Both blocks are compatible with OLI kinetics, allowing users to incorporate reaction kinetics seamlessly within separation unit operations.

Conclusion

The integration of OLI’s EFLASH and FRACHEM unit operations into Aspen Plus represents a powerful advancement for process engineers working with complex electrolyte systems. These blocks provide robust phase separation capabilities and enhanced flash stability under extreme compositional conditions. By leveraging OLI’s rigorous thermodynamic framework within Aspen’s simulation platform, users can achieve a more complete and reliable representation of real-world chemical behavior. For organizations seeking precision, reliability, and chemical insight, these unit operations serve as indispensable tools in advanced process modeling.