Preparation of high-surface-area PAN-based activated carbon by solution-blowing process for CO 2 adsorption

Abstract

High-surface-area activated carbon obtained from ultra-thin PAN fibers was evaluated as CO 2 adsorbent in a simulated flue gas stream. These carbons were prepared from ultra-thin PAN fibers by means of stabilization, activation, and carbonization. By changing the stabilization temperature, it is possible to control the pore size from supermicropores (0.7–2.0 nm) to mesopores (2–5.5 nm). The surface area of the carbon can be over 2500 m 2g −1. Both textural properties and nitrogen functionality influence the CO 2 adsorption performance of the adsorbents. The ultra-thin PAN fibers stabilized at 533 K (AC533) achieved the highest CO 2 gravimetric equilibrium capacity of 5.53 mmol g −1 in a binary mixture of 15% CO 2 in N 2 at 323 K, while AC493 had the highest CO 2 dynamic adsorption of 2.70 mmol g −1 in a N 2/CO 2/H 2O mixture (83/10/7% v/v) at 323 K. The textural properties, the micropore surface and micropore volume obtained from micropores below 1.1 nm, have a significant effect on CO 2 dynamic adsorption. The stabilization temperature affects the nitrogen group present, as determined by XPS, which enhances the specific adsorbent-adsorbate interaction for CO 2.