High efficiency CO2 sorption property of Li4SiO4 sorbent pebbles via a simple rolling ball method

At present, the Li4SiO4 sorbents have been getting widespread attention for mitigating the release of CO2 gas owing to its stable cyclic property, higher capturing ability, and lower regeneration temperatures. In this work, a facile rolling ball method is first proposed to fabricate Li4SiO4 sorbent pebbles, which overcomes the low production efficiency, poor adsorption stability, and high production cost adopted in the previous literature. In the rolling ball process, the spray granulation process was involved to decrease the specific surface area of ceramic powder, which makes it easier for powder self-agglomerate to form pebbles via the centrifugal force with the assistance of PVA polymer solution. Moreover, the phase composition, the specific surface area, the shaping principle, and the microstructure of Li4SiO4 sorbent pebbles were studied, respectively. The result shows that the Li4SiO4 pebbles sintered at 900 °C for 2 h present a superior comprehensive performance with a homogeneous diameter of 1.2 mm, good sphericity of 0.95, high crushing load of 65 N, and suitable porosity of 6.28 %. Compared with Li4SiO4 powder, the spherical pebbles performed superior CO2 adsorption ability (0.304 g CO2/g sorbent) and excellent cyclic stability in a 100% CO2 environment owing to its large number of uniform pores channels produced by binder solution at high temperature. Therefore, the rolling ball process is a potential method for the batch production of Li4SiO4 pebbles to capture CO2 stably in the future.