Carbon dioxide capture and storage (CCS) is a technology that prevents isolating a massive amount of carbon dioxide discharged from sources such as power plants, steel plants, or cement plants using fossil fuels.
Among the CCS technologies, the carbon dioxide capture technique is a core technique that occupies about 70% to about 80% of the total cost, which is mainly classified into a postcombustion technology, a pre-combustion technology, and an oxy-fuel combustion technology (Current Status of Development in Carbon Dioxide Capturing Technology, LEE, Chang Geun, Prospect of Industrial Chemistry, Vol. 12, No. 1, 2009).
The post-combustion technology is a technique that removes carbon dioxide (CO2) produced from fossil fuel by absorbing/adsorbing to or reacting with various separating media, and the pre-combustion technology separates carbon dioxide before combustion, which separates out carbon dioxide (CO2) from among a gas mixture of carbon dioxide (CO2) and hydrogen (H2) after converting CO2 and hydrogen by pre-treating the gas that is synthesized through a gasification process of fossil fuel, such as coal. Also, the oxy-fuel combustion technology uses only oxygen in the air when combusting fossil fuel, instead of using the atmosphere, and thus, the technology facilitates carbon dioxide (CO2) capture. Among the technologies, the post-combustion technology has been the most common process currently being used to capture carbon dioxide.
As the post-combustion technology, which captures carbon dioxide in the fuel gas after combustion, a method of separating carbon dioxide by using an absorbent has been used as a common technique, but problems have been occurring such as an increase in driving energy and waste water generation due to use of liquid solution, and thus methods of capturing carbon dioxide using an absorbent that may resolve the problems have been developed.
The main flow of the methods of adsorbing, regenerating, and separating carbon dioxide by using an adsorbent has focused on improvement in performance of the absorbent and the process thereof. In particular, studies on increasing adsorption performance by combining chemical adsorbents using chemical characteristics and physical adsorbents using physical characteristics have been actively conducted.
Korean Patent No. 0879312 discloses a novel type of a carbon dioxide adsorbent that is prepared by impregnating zeolite with lithium hydroxide to improve adsorbent performance. However, the adsorbent has a low adsorbing ratio and a low durability of adsorption, as well as a low endurance. Thus, a carbon dioxide adsorbent having an improved adsorbing ratio, a high durability of adsorption, as well as a high endurance, is needed.