Particle size dependence of CO2 absorption rate of powdered Li4SiO4 with different particle size

Abstract

Particle size dependence of CO2 absorption rate of powdered Li4SiO4 with four kinds of particle sizes was studied by SEM observation, particle size distribution measurement, and thermogravimetry. Average particle sizes of the powdered single phase Li4SiO4 samples were estimated about 26 μm, 34 μm, 53 μm, 70 μm, respectively by the particle size distribution measurement and SEM observation. The measurement of apparent rate constant k for the CO2 absorption reaction showed that k values of all the powdered Li4SiO4 samples increase with the increasing measurement temperature T, following the Arrhenius equation in the region of 620-660°C, while the k values abruptly increase deviating the Arrhenius equation over 670°C. It was also noted that the k values seem to depend on the particle size of the powdered Li4SiO4 samples, that is, the k values increase with the decreasing particle size. Moreover, difference between the k values of all the powdered samples at same temperature was found small in the region of 620-660°C, while the difference was found large over 670°C. For Li4SiO4 with smaller particle size, Δk = k700°C -k660°C was found larger, vice versa, the Δk was found smaller for Li4SiO4 with larger particle size. The values seem to correspond with reaction mechanism for CO2 absorption of Li4SiO4 particle.

CO2 absorption and structural phase transition of .ALPHA.-LiFeO2

“…6) Furthermore, LiFeO2 has an advantage over other lithium salts such as Li2ZrO3, 7) Li4SiO4, 4), 8) and Li4TiO4 9) because it absorbs CO2 and releases CO2 at lower temperatures than other compounds. 6) However, the CO2 absorption ratio of LiFeO2 is low because the formation of Li2CO3 on the surface of LiFeO2 particles 6) prevents CO2 molecules from diffusing inside the particles.…”

CO2 Absorption and Desorption Properties of Single Phase Ba2Fe2O5 and Analysis of Their Mechanism Using Thermodynamic Calculation

“…Lithium-containing oxides, such as Li 2 ZrO 3 and Li 4 SiO 4 , have been investigated as CO 2 absorbents [1][2][3][4] and, in particular, Li 4 SiO 4 has much attention because of its high CO 2 absorption efficiency, which is supposed to depend on the following reaction (1). 4 Li 4 SiO 4 ðsÞ þ CO 2 ðgÞ $ Li 2 CO 3 ðsÞ þ Li 2 SiO 3 ðsÞ ð 1Þ…”

Reversible Reaction with CO2 and Control of CO2 Absorption/Desorption Properties of Ba2(Fe1−xInx)2O5 Solid Solutions

“…It was observed that the mass variation for CO 2 absorption saturated at 12.7% after 15 h and that the mass variation for CO 2 desorption saturated at À11.4% after 16 h. Therefore, it can be concluded that Ba 2 (Fe 1Àx In x ) 2 O 5 reversibly reacts with CO 2 by reaction (3). It was observed that the mass variation for CO 2 absorption saturated at 12.7% after 15 h and that the mass variation for CO 2 desorption saturated at À11.4% after 16 h. Therefore, it can be concluded that Ba 2 (Fe 1Àx In x ) 2 O 5 reversibly reacts with CO 2 by reaction (3).…”