Preparation of an Ultrafine Solid Amine Fiber by Electrospinning and Its CO₂ Adsorption Behavior

The adsorption capacity of a solid amine adsorbent for CO2 adsorption is often limited by the number of amino groups on the adsorbent surface. In this paper, a kind of ultrafine solid amine fiber (PSN) was prepared by direct electrospinning of polyethylenimine blends, which could provide plentiful amino groups on the fiber surface without further modification and would improve the CO2 adsorption capacity and amino utilization efficiency of the fibrous adsorbent. The effects of the adsorbent structure on the CO2 adsorption performance of PSN was investigated. The results indicated that the fibrous structure and higher outer surface area of PSN can greatly improve its adsorption capacity and adsorption rate for CO2. Under the simulated flue gas conditions (90% N-2/10% CO2) at 25 C-degrees, the CO2 adsorption capacity of PSN fiber is 2.10 mmol/g, and its CO2 adsorption capacity could reach 4.98 mmol/g at 75 C-degrees. The diameter of the fiber obviously affects the CO2 adsorption behavior of the solid amine adsorbents; an increase of the fiber diameter would result in the decrease of the adsorption capacity of the adsorbents. PSN has good regeneration stability, and its CO2 adsorption performance remained almost unchanged after a number of regeneration cycles.