(542b) Process Development for Phase-Changing Aminosilicone-Based CO2-Capture Absorbents

Liquid aminosilicone-based absorbents have been developed that have the potential to significantly reduce the cost of CO₂ capture from pulverized coal power plants.  Upon exposure to CO₂, these novel absorbents solidify, thereby enabling innovation in CO₂ capture process design.  Compared to MEA-based CO₂ capture absorbents, the phase-changing aminosilicones have the potential to reduce CO₂ capture cost through higher CO₂ absorption capacity, greater thermal stability, and reduced solvent losses due to volatility.  Furthermore, the phase-changing behavior of these new absorbents and the absence of aqueous diluent enable the use of more energy-efficient separations process units.  Finally, by enabling pressurized desorption of CO₂, the energy required to compress the clean CO₂ stream pre-sequestration is significantly reduced. 

A process is being developed in which CO₂ is removed from simulated flue gas in a spray absorber, and the solid CO₂-sorbent complex is slurried in liquid absorbent for transport to a pressurized desorber.  In the desorber, the solids are heated to release CO₂ and regenerate the liquid absorbent for recycle.  Experiments at the lab scale focusing on spray absorption, slurry rheology, and pressurized desorption are in progress to generate data needed to scale up the process.  These results and their effect on estimated CO₂ capture economics will be discussed.