A new nano CaO-based CO2 adsorbent prepared using an adsorption phase technique

This study describes for the first time micro-scale hydrolysis has been used in the adsorption phase to prepare a nano CaO-based CO2 adsorbent with a highly durable sorption capacity. The hydrolysis of Ti(OC4H9)4 to form TiO2 was used to prepare TiO2-coated nano CaCO3, which was then calcinated to prepare a nano CaO-based CO2 adsorbent with a controlled coating layer. The coating compactness was defined for the first time in this study to describe the mole ratio of Ti to Ca on the surface of the nano CaCO3. The coating compactness and the durability of the sorption capacity of samples with varying TiO2 content, hydrolysis temperature, and ester concentration were studied in detail. The properties of the reactive adsorption of the prepared nano CaO-based CO2 adsorbents were tested using a thermo-gravimetric analyzer. The results showed that, of the conditions tested, the TiO2 content exerts the most influence on the durability of the sorption capacity. The nano CaCO3 that was coated with 10 wt.% TiO2 and prepared under 20 °C, which has a corresponding coating compactness of 1.0, exhibited a much more durable CO2 sorption capacity than the other prepared samples.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights• Using “adsorption phase technique”, a coating layer of 4.5 nm–11.6 nm was formed with the TiO2 content increasing. • TiO2 content played an important role of CO2 adsorption durability. • Compact factor between 0.8 and 1.3 was tested to relate the adsorption stability.