Hollow Fiber Adsorbents for CO2 Removal from Flue Gas

The nation's pulverized coal infrastructure is aging, and implementation of current retrofit postcombustion capture methods is extremely expensive. This paper describes a technology based on hollow polymeric fibers with sorbent particles embedded in the porous fiber wall to enable postcombustion CO2 capture via a rapid temperature swing adsorption (RTSA) system. The system takes advantage of the hollow fiber morphology by passing cooling water through the bores during sorption to maximize sorption capacities and steam through the bores during desorption to desorb CO2 efficiently. The thin-walled hollow fibers offer the advantage of rapid heat and mass transport. To avoid mass transfer between the core and the fiber sheath, a dense lumen layer is used on the interior of the fiber wall. This system has advantages over competing technologies. Specifically, the fiber sorbent contactor minimizes flue gas pressure drop across the bed, while maximizing sorption efficiencies via rapid thermal cycles and low regenerative thermal requirements.