Research progress of non-aqueous absorbents for carbon dioxide capture with low energy consumption: A review

Abstract

Amine-based absorption/desorption systems are a well-established method for CO₂ capture process due to their fast absorption rates, high CO₂ loading, and recyclability. However, the significant drawback is the high energy required for solvent regeneration and heavily water evaporation significantly limits their efficiency. To overcome this, non-aqueous CO₂ absorbents have been developed as an alternative, offering advantages such as thermal stability, high absorption capacity, and reduced energy consumption compared to traditional aqueous amine systems. Consequently, research focuses on developing cost-effective, efficient, and sustainable non-aqueous absorbents. This review summarizes findings from 2011 to 2024 on CO₂ capture which employing non-aqueous absorbents, including absorption performance, mechanisms, energy consumption, and challenges. The first section examines amine-based non-aqueous solutions, encompassing single and blended amine absorbents. The second section explores CO₂ binding liquids, and phase-changed amine absorbents. Energy consumption and operational cost comparisons among non-aqueous absorbents in different systems were conducted due to its critical importance. In conclusion, this review highlights the advantages, challenges, and potential of non-aqueous absorbents in CO₂ capture. Addressing energy consumption issues and pursuing sustainable alternatives contribute to progress in carbon capture for mitigating climate change. Future research should prioritize optimizing non-aqueous systems to balance energy savings, cost-effectiveness, and scalability to combat climate change effectively.