(664f) Li4SiO4-Based Novel Solid Fluidizable Sorbent for CO2 Capture:

This study investigates the cyclic use of several sorbents for CO₂ capture and comparative study of thermodynamic analysis to predict sorbent regeneration conditions and thermal levels where sorbent kinetics change from CO₂ absorption to CO₂ desorption. It is expected cycling processes with CO₂ capture and sorbent regeneration and alternative sorbents (e.g. lithium ortho-silicate based novel sorbent) could lead to significant energy savings with limited sorbent sintering. On this basis CO₂ absorption and desorption were quantified at various temperatures and CO₂ partial pressures. Temperature Programmed Carbonation (TPC) and Temperature Programmed Decarbonation (TPDC) were developed using temperature programmed equipment at CREC-UWO laboratories employing several sorbents subjected to a 5°C/min temperature ramp and with a gas stream containing a 10% CO₂ mole fraction. Calcium carbonate, lithium orthosilicate and a novel lithium orthosilicate modified sorbent are considered for these runs. TPC-TPDC runs confirm thermodynamic predictions for thermal inversion points. Furthermore, TPD-TPDC runs show that the novel lithium orthosilicate based sorbent provides a very stable and increased CO₂ sorption capacity over 10 absorption-regeneration cycles, while calcium carbonate displays a reduced CO₂ sorption capacity with cyclic operation. This fluidizable novel sorbent can significantly contribute towards CO₂ removal from flue gases emitted by power plants. The thermodynamic and TPC-TPDC analysis of the present study also provides a conceptual design from developing CO₂ capturing processes with alternative sorbents such as lithium ortho-silicate based sorbent.