This review summarizes the application of process simulations in the development of ionic liquid (IL)-based technologies, focusing on their role in selecting optimal ILs for industrial processes and enhancing their industrial transferability. The review highlights the use of predictive thermodynamic models, such as COSMO-SAC/RS and UNIFAC, in commercial software like Aspen Plus to analyze key IL applications, including CO₂ capture, conversion, gas separation, liquid–liquid extraction, extractive distillation, refrigeration cycles, and biorefinery. Process simulations enable the selection of ILs based on criteria such as thermodynamic and kinetic properties, price, thermal stability, and environmental impact. They also facilitate the design of operational units, equipment sizing, and process optimization to improve the competitiveness and sustainability of IL-based technologies. The review discusses the limitations of IL-based processes, such as high viscosity and the need for regeneration, and emphasizes the importance of process simulations in overcoming these challenges. It also highlights the integration of IL product and process designs to minimize solvent and energy requirements. The review concludes that process simulations are essential for advancing IL-based technologies, enabling the development of digital prototypes, and guiding experimental research. The review also discusses the use of predictive thermodynamic models in process simulations, which allow for the estimation of IL properties without experimental data, and the importance of process simulations in evaluating the environmental impact of IL-based processes. The review emphasizes the need for further research to improve the accuracy and efficiency of process simulations in IL-based technologies.This review summarizes the application of process simulations in the development of ionic liquid (IL)-based technologies, focusing on their role in selecting optimal ILs for industrial processes and enhancing their industrial transferability. The review highlights the use of predictive thermodynamic models, such as COSMO-SAC/RS and UNIFAC, in commercial software like Aspen Plus to analyze key IL applications, including CO₂ capture, conversion, gas separation, liquid–liquid extraction, extractive distillation, refrigeration cycles, and biorefinery. Process simulations enable the selection of ILs based on criteria such as thermodynamic and kinetic properties, price, thermal stability, and environmental impact. They also facilitate the design of operational units, equipment sizing, and process optimization to improve the competitiveness and sustainability of IL-based technologies. The review discusses the limitations of IL-based processes, such as high viscosity and the need for regeneration, and emphasizes the importance of process simulations in overcoming these challenges. It also highlights the integration of IL product and process designs to minimize solvent and energy requirements. The review concludes that process simulations are essential for advancing IL-based technologies, enabling the development of digital prototypes, and guiding experimental research. The review also discusses the use of predictive thermodynamic models in process simulations, which allow for the estimation of IL properties without experimental data, and the importance of process simulations in evaluating the environmental impact of IL-based processes. The review emphasizes the need for further research to improve the accuracy and efficiency of process simulations in IL-based technologies.