Hybrid ionic liquid amine solvents for CO₂ capture from natural gas: a systematic review of techno-economic and environmental performance

The global transition to clean energy demands reliable low-carbon fuels, positioning natural gas (NG) as a critical bridge in mitigating climate change. Its lower greenhouse gas emissions compared to coal and oil, combined with abundant reserves, make NG a vital option for sustainable power generation and industrial use. However, its environmental benefits depend on effective purification, particularly CO2 removal, which determines gas quality, efficiency, and processing costs. This study critically reviews recent developments (2000-2024) in CO2 capture from NG using hybrid ionic liquid-amine systems, evaluating techno-economic and environmental performance. A systematic evaluation was performed using published experimental, modelling, and process simulation data. Published data concerning experimental, modelling, and techno-economic data were considered in a systematic evaluation to compare the performance of conventional absorption, adsorption, membrane, cryogenic and hybrid solvent processes. Hybrid IL-amine solvents achieve 93-98 % CO2 capture efficiency with 20-30 % lower regeneration energy compared to MEA, although at TRL 5-6. These developments highlight the potential of NG to serve as a cleaner transitional fuel while reinforcing the need for integrated policies and technologies that ensure responsible production and utilization. Advancing purification technologies are therefore central to maximizing the role of natural gas in the global clean energy transition.