Post-spinning infusion of poly(ethyleneimine) into polymer/silica hollow fiber sorbents for carbon dioxide capture

Amine-loaded hollow fiber sorbents for CO2 capture from dilute gas streams are created using a novel post-spinning amine-infusion technique. This technique infuses poly(ethyleneimine) (PEI) into cellulose acetate/mesoporous silica hollow fiber sorbents during the solvent exchange steps after dry-jet, wet-quench, non-solvent induced phase separation spinning. A suitable post-spinning infusing solution was found to be 10% PEI in methanol with an infusion time of 4 h. After amine infusion, the 51 wt% silica hollow fiber sorbents are demonstrated to have a nitrogen loading of 0.52 mmol/g-fiber and a CO2 uptake of 1.2 mmol/g-fiber, at equilibrium. Amine-loaded fibers are packaged into a shell-and-tube module and exposed on the shell side to simulated flue gas with an inert tracer (10 mol% CO2, 80 mol% N-2 and 10 mol% He at 100% relative humidity; 1 atm, 35 degrees C). The fibers are shown to have a breakthrough CO2 capacity of 0.58 mmol/g-fiber and CO2 uptake after 20 min of 0.92 mmol/g-fiber (1 atm and 35 degrees C). Under the same conditions, the water uptake was found to be 3.2 mmol/g-fiber. The preparation of amine-containing polymeric hollow fibers and demonstration of their CO2 adsorption properties is an important step towards realizing new, scalable process configurations for supported amine sorbents relevant to post-combustion CO2 capture. (C) 2013 Elsevier B.V. All rights reserved.