Solid-state sorbent grabs CO2, doesn’t hog energy
2009 R&D 100 Winner
Anthropogenic carbon dioxide emissions are now widely thought to contribute to global warming. As a result, legislation that will require reductions of such emissions from industrial and individual sources will likely be enacted soon. The traditional scenario for removal of acid gases, such as carbon dioxide and hydrogen sulfide, from gas streams is an absorption system based on a solvent consisting of aqueous monoethanolamine (MEA). Such systems run at absorption temperatures close to standard cooling-water temperatures, and at desorption temperatures around 120°C. Any further process improvements to aqueous amine scrubbing will be minimal and certainly not of the magnitude that would decrease the energy consumption by 30-50%—a target goal for this effort. The National Energy Technology Laboratory-developed Clay-Liquid CO2 Removal Sorbent addresses major problems that were encountered with the current commercial liquid amine process. The liquid-impregnated clay sorbent is capable of capturing CO2 in the presence of water vapor at 30-60°C and can be regenerated at temperatures around 80-100°C. The liquid-impregnated clay sorbent is available in small particle sizes (< 200 ?m) suitable for fluidized bed or large particle sizes (1 mm) suitable for moving bed or fixed bed reactor operations. The sorbents are designed to be placed in a capture unit that is downstream of the flue gas desulfurization unit to minimize the interactions with the strong acid gas contaminants.
CO2 removal sorbent