Physicochemical Properties and CO₂ Absorption Capacity of Bio-Based Ionic Liquid Solutions: High-Pressure PVT Measurements

Mitigating climate change requires innovative strategies to reduce CO₂ emissions. This thesis explores choline prolinate and dimethyl pyrrolidinium prolinate, two bio-based ionic liquids, as potential alternatives for post-combustion CO₂ capture. While ILs offer tunable properties, low volatility, and excellent thermal stability, their inherently high viscosity can hinder mass transfer and CO₂ absorption efficiency. To overcome this limitation, this study investigates the dilution of ILs with dimethyl sulfoxide to optimize the balance between chemical reactivity and mass transfer while preserving the advantages of bio-based ionic liquids. The ILs were synthesized through controlled reactions using bioavailable precursors and characterized using differential scanning calorimetry, physical property measurements, ATR-IR spectroscopy, and thermogravimetric analysis-infrared. CO₂ absorption performance was assessed through gravimetric analysis and Pressure–Volume–Temperature (PVT) experiments under various pressure and temperature conditions. The results indicate that dimethylsulphoxide dilution significantly reduces viscosity, enhancing CO₂ uptake and improving absorption kinetics. These findings highlight the potential of bio-based ionic liquids as sustainable, efficient alternatives to traditional amine-based solvents for CO₂ capture, contributing to greener post-combustion technologies.