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

Abstract

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 4h. After amine infusion, the 51wt% silica hollow fiber sorbents are demonstrated to have a nitrogen loading of 0.52mmol/g-fiber and a CO2 uptake of 1.2mmol/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 (10mol% CO2, 80mol% N2 and 10mol% He at 100% relative humidity; 1atm, 35°C). The fibers are shown to have a breakthrough CO2 capacity of 0.58mmol/g-fiber and CO2 uptake after 20min of 0.92mmol/g-fiber (1atm and 35°C). Under the same conditions, the water uptake was found to be 3.2mmol/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.