(400k) Enhancing the Accuracy of Ionic Liquid-Based Extractive Distillation Simulations for Refrigerant Separation By Estimating Vapor Pressure of the IL Using Non-Isothermal TGA

The separation of refrigerant mixtures using extractive distillation with an ionic liquid (IL) is being developed for the reclaim industry. This method has been demonstrated to effectively separate azeotropic refrigerant mixtures with high purity, enabling the reclamation, recycling, and repurposing of refrigerants. This process is essential for managing the existing large quantities of refrigerant stockpiles and mitigating the environmental impact.

ASPEN Plus simulations are used to predict the performance of a pilot extractive distillation when a specific ionic liquid (IL) is selected as an entrainer. The very low vapor pressure of the ILs poses a challenge in accurately determining the vapor pressure. Predictions based on property models and EOS often overestimate the vapor pressure of the ILs, which may impact the accuracy of product purity predictions. In this work, the vapor pressure estimated by non-isothermal Thermogravimetric Analysis (TGA) is compared with ASPEN Plus predictions and experimentally measured vapor pressure to assess the accuracy and implication for simulation reliability.