Development of KNaTiO3 as a novel high-temperature CO2 capturing material with fast sorption rate and high reversible sorption capacity

摘要

In addition to the previous well studied CaO, Li4SiO4, and Li2ZrO3, a new type of high-temperature CO2 capture material KNaTiO3 was revealed for the first time, which exhibited excellent sorption performance, including a superior CO2 capture capacity and fast sorption rate under different concentrations of CO2. By decreasing the CO2 concentration from 100 to 20 vol%, the CO2 uptake only slightly decreased from 19.0 to 17.4 wt%, suggesting this sorbent is very promising for practical applications. Isothermal CO2 sorption and double exponential mode fitting demonstrated that the sorption-desorption equilibrium can be reached within 10 min, with the diffusion as the limiting step. Moreover, the good regeneration ability and prominent cycling stability of KNaTiO3 can be observed during 20 cycles at 700 degrees C with a pressure swing adsorption scheme. A mechanism and reaction process were proposed. This work represents a great breakthrough in the development of new high-temperature CO2 capturing materials.