Pressure swing adsorption(PSA) technology provides plenty of advantages for CO₂ capture from flue gas. However, flue gas always contain some water vapor, which causes a great challenge to capture CO₂ by using conventional adsorbents. To solve this bottleneck problem, improving pressure swing adsorption processes and developing novel moisture-insensitive adsorbents have become the most important ways. In this paper, novel processes for CO₂ capture from wet flue gases is introduced, which consist of multilayered adsorption processes and microwave assisted vacuum regeneration technologies. Furthermore, the recent research progress of effective adsorbents for CO₂ capture from wet gases is summarized. Their physicochemical properties as well as adsorption mechanisms of CO₂ and water vapor are systematically elucidated. Based on that, the problems existing in CO₂ capture from highly humid flue gas by pressure swing adsorption technologies are further discussed and follow-up studies are prospected. We believe that with the improvement of the PSA processes and development of novel adsorbents, the cost of CO₂ capture from wet flue gas will be further reduced in the near future, which is of great significance for greenhouse gases reduction from humid waste gases, such as flue gases from power plants and exhaust gases from factories.
1 Introduction
2 Processes for CO₂ capture from humid flue gas
2.1 Multilayer adsorption
2.2 Microwave assisted vaccum regeneration
3 Adsorbents for CO₂ capture from humid flue gas
3.1 Zeolites
3.2 Activated carbon
3.3 Activated alumina
3.4 MOFs
3.5 Silicon molecular sieves
3.6 Adsorbents after surface modification
4 Conclusion