(485b) Structure and Thermochemistry of Phase-Changing Aminosilicone-Based CO2-Capture Absorbents
Liquid aminosilicone-based CO2 absorbents that solidify upon reaction with CO2 have been developed. These phase-changing absorbents have the potential for superior performance for capturing CO2 from the flue gas of pulverized-coal power plants. A process has been conceived in which the liquid aminosilicones are reacted with the CO2 in flue gas using a spray column. The solid CO2-rich powders that form are then collected and sent to a desorber where the powder is heated, releasing high-purity CO2 and regenerating the liquid aminosilicone, which is recycled back to the spray column. Compared to a conventional monoethanol amine-based CO2-capture process, phase-changing absorbents have potentially higher CO2 capacity, greater thermal stability, and simplified separations, due to their low volatility. Studies have been performed to evaluate the particle sizes and morphologies of the solid powders formed in a spray column when these materials are reacted with the CO2 in simulated flue gas. The crystalline structure of these materials has been studied, and thermochemical methods have been used to study the absorption and desorption of CO2.