Preparation, stability, and enhanced CO2 absorption and desorption of nanofluids: Review and perspectives

Abstract

In recent years, the continuous and substantial emission of carbon dioxide (CO₂) has become a significant environmental concern. To deal with this problem, Carbon capture, utilization, and storage (CCUS) technologies have been developed, with carbon capture representing both the foundational and most cost-intensive component of CCUS. Therefore, enhancing the efficiency of carbon capture and reducing associated costs is crucial. Nanofluids have attracted considerable attention from researchers due to their remarkable performance in enhancing CO₂ absorption. This paper summarizes the preparation methods for nanofluids, strategies to improve their stability, and techniques for assessing stability. It discusses the mechanisms of enhanced CO₂ absorption by nanofluids and analyzes the factors influencing CO₂ absorption, categorized into elements of the nanofluid itself and operational parameters of the absorption system. Importantly, these influencing factors are interrelated and may collectively impact the overall absorption process. This paper includes a quantitative analysis of the factors influencing the absorption performance of nanofluids, a topic not previously addressed in prior reviews. It also highlights unique insights from simulation studies on CO₂ absorption enhancement by nanofluids. The paper gives the mechanisms through which nanofluids promote CO₂ desorption, along with the factors affecting the desorption efficiency. Lastly, it demonstrates the stability of nanoparticles in alkaline base fluids and the long-term CO₂ absorption performance of nanofluids during the absorption-desorption cycle, topics not previously reviewed. This work will assist new researchers in understanding the field and provide direction for future research endeavors.