TITLE:
Evaluation of Carbon Dioxide Absorption Characteristics Lithium Ortho-Silicate in Chemical Heat Storage
AUTHORS:
Takehiro Esaki, Daichi Iwase, Noriyuki Kobayashi
KEYWORDS:
CO2 Capture, Chemical Heat Storage, Lithium Ortho-Silicate, Absorption Rate
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.5 No.4,
April
30,
2017
ABSTRACT: We report the development of technology that may contribute to a reduction in greenhouse gas emissions and improve the energy efficiency of the CO2 capture process. Lithium ortho-silicate is a suitable solid sorbent for capturing CO2. This reversible chemical reaction is also applicable to chemical heat storage. The absorption reaction characteristics of lithium ortho-silicate were studied by a thermogravimetric method and a volumetric method that demonstrated the influence of heat and mass transfer limitations in a packed bed designed to be as small as possible. We developed a method for measuring the absorption reaction characteristics in the experiments. In the experiments, a constant conversion fraction of 60% was observed. The reaction system was stable to repetition. The CO2 absorption rate depends on the CO2 pressure and reactor temperature. The absorption rate was determined at several reactor temperatures when the conversion fraction was 0.3. In this study, the maximum absorption rate was obtained at 670oC. It was demonstrated that lithium ortho-silicate is suitable for use in a chemical heat storage system.