Research progress of CaO-based absorbents prepared from different calcium sources

Abstract

CaO-based absorbent have been regarded as an ideal high-temperature CO2 absorbent. However, as the number of cycles increases, the CO2 absorption performance gradually decreases. In order to maintain high CO2 removal efficiency, a large amount of fresh absorbent is required, resulting in a significant increase in economic costs and equipment load. Therefore, it is urgent to reduce the raw material cost of the CaO-based absorbent and maintain a high cycle absorption efficiency and stability by modification. Firstly, the decarburization principles of CaO-based absorbent and the reasons for absorption performance degradation were analyzed. Then, the main modification methods and thee respective effects of CaO-based absorbents prepared using different calcium sources (natural minerals, chemical agents, bulk industrial solid waste) were summarized, from the aspects of enhancing absorption efficiency, improving cycling stability and reducing costs. The results show that the CaO-based absorbent prepared by industrial solid waste with high calcium content has good CO2 absorption efficiency and cycle stability. A small amount of impurities in the solid waste may help to improve the corrosion resistance and wear resistance of CaO-based absorbent. In addition, the production cost of CaO-based absorbents can be minimized through the integration with industrial production.