Modeling and Simulation of Pre-Processing System for Direct Lithium Extraction (DLE) Using Aspen Plus and Aspen Adsorption
Project Description
The rapid growth of electric vehicles and energy storage technologies has significantly increased global lithium demand. Direct Lithium Extraction (DLE) has emerged as a sustainable alternative to conventional evaporation ponds, offering faster processing, reduced land use, and improved environmental performance. This project focuses on modeling and simulating the pre-processing stage of a DLE system using Aspen Plus, Aspen Properties, and Aspen Adsorption to prepare raw brine for downstream lithium recovery.
The case study is based on Qarhan brine, modeled using the apparent component approach. The raw brine at 25°C and 1 bar is pressurized to 4.1 bar, mixed with recycle, heated to 185°C, and subsequently throttled before entering a flash drum. The flash operation removes water vapor, thereby concentrating lithium and associated salts in the liquid phase. The concentrated brine is either partially recycled or directed to downstream adsorption-based lithium recovery systems.
The steady-state Aspen Plus flowsheet is further imported into Aspen Plus Dynamics and Aspen Adsorption for dynamic modeling of lithium extraction using cyclic sorbent processes. The integrated modeling approach ensures thermodynamic consistency while enabling evaluation of lithium enrichment, water removal efficiency, and process integration with adsorption systems.
Process Flow Diagarm
Optimization Strategy
The optimization strategy focuses on maximizing lithium enrichment while minimizing energy consumption and water loss. Key operating variables include heating temperature (185°C), flash pressure (1.085 bar), and recycle ratio. Sensitivity analysis is performed to determine optimal flash conditions that enhance lithium concentration without excessive vaporization energy requirements.
Process integration optimization ensures compatibility between the pre-processing unit and downstream adsorption columns. By enriching lithium concentration by approximately 67% and reducing water content by about 7%, the volumetric load on adsorption systems is significantly reduced. This lowers column size requirements, improves adsorption cycle efficiency, and enhances overall process sustainability.
Brine Thermodynamic Modeling
The apparent component approach is used to model Qarhan brine composition. Aspen Properties ensures accurate representation of electrolyte behavior and phase equilibrium during
heating and flashing operations.
Evaporation and Flash Concentration System
The pre-processing system includes pumping, heating, throttling, and flash separation. Water
vapor removal in the flash drum increases lithium salt concentration in the liquid phase.
Dynamic Integration with Adsorption Systems
The steady-state Aspen Plus model is imported into Aspen Plus Dynamics and Aspen
Adsorption to simulate cyclic lithium recovery processes. This integration supports rigorous
evaluation of adsorption performance under realistic feed conditions.
Projects Insight
Lithium Enrichment Performance
● 67% increase in lithium concentration
● Improved downstream adsorption efficiency
● Reduced feed volume requirements
Water Removal Efficiency
● Approximately 7% water removal
● Concentrates dissolved salts
● Reduces post-processing waste
Energy–Concentration Trade-Off
● Heating to 185°C enables flash separation
● Pressure reduction drives vaporization
● Optimization minimizes excess energy use
Process Integration Capability
● Seamless transfer to Aspen Dynamics
● Compatible with Aspen Adsorption
● Enables cyclic process simulation
Sustainable DLE Advantage
● Lower land footprint vs. evaporation ponds
● Faster processing time
● Reduced water consumption
Industrial Scalability
● Suitable for high-salinity brines
● Flexible recycle configuration
● Supports modular lithium recovery plants
Conclusion
This project presents a comprehensive simulation of the pre-processing stage for Direct Lithium Extraction using Aspen Plus and Aspen Adsorption. By concentrating Qarhan brine through controlled evaporation and flash separation, lithium content is enriched by 67%, improving downstream adsorption efficiency while reducing volumetric processing requirements. The integrated steady-state and dynamic modeling framework provides a robust foundation for sustainable lithium recovery process design, optimization, and scale-up in response to growing global demand for battery-grade lithium.