Novel ionic liquid for pre-combustion CO₂ capture: Structure optimization via modified TRIC/COSMO-SAC framework and Aspen Plus integration

Given the anticipated increase in H 2 production and the transition to a low-carbon economy, sustainable CO 2 capture methods, such as physical absorption using ionic liquids (ILs), are paramount. This study introduces a new approach to model the novel IL [HEMMIM][CCN3] by incorporating the modified translation-rotation-internal coordinate (TRIC) system for molecular geometry optimization with a COSMO-based/Aspen Plus approach. Conductor-like screening model within density-functional theory (COSMO-DFT) calculations using Amsterdam Modeling Suite (AMS/ADF) software were carried out on the optimized IL ion-pair to compute parameters needed for the conductor-like screening model for real solvents (COSMO-RS) and conductor-like screening model – segment activity coefficient (COSMO-SAC) supporting the process model. Aspen Plus is used to synthesize and model a pre-combustion CO 2 capture process to assess the performance of [HEMMIM][CCN3] relative to an established IL [BMMIM][TF2N] via energy, exergy, and economic analysis (3E). At optimized conditions, both ILs achieved a relatively close CO 2 recovery rate, with high H 2 purity, while the novel IL [HEMMIM][CCN3] showed 57 % less total duty requirements and roughly 80 % lower exergy loss than those for the [BMMIM][TF2N] system, resulting in reduced operating and utility costs by 53 % and 57 %, respectively.