Reproducibility of CO₂ Absorption and Emission for Cylindrical Pellet Type Lithium Orthosilicate

抄録

For the purpose of carbon dioxide (CO₂) capture at high temperature, Toshiba developed a series of novel CO₂ absorbents using lithium-containing oxides. Among these absorbents, lithium orthosilicate (Li₄SiO₄) shows highest reaction rate of CO₂ absorption and emission, which result in weight change of up to 36%. Furthermore, the emission was performed at a much lower temperature than that of CaO.
This paper is our first report regarding reproducibility of CO₂ absorption and emission using Li₄SiO₄ absorbent in the shape of cylindrical pellet. The pellets were heated at 600°C for absorption and 800°C for emission in a gas flowing condition of 20% CO₂ up to 50 cycles. The reproducibility was evaluated by the retention ratio of absorption rate to the initial one. In addition, the degradation mechanism of reproducibility was investigated in term of the change of microstructure.