The Resource Utilization of Poplar Leaves for CO[sub.2] Adsorption

Every late autumn, fluttering poplar leaves scatter throughout the campus and city streets. In this work, poplar leaves were used as the raw material, while H[sub.3]PO[sub.4] and KOH were used as activators and urea was used as the nitrogen source to prepare biomass based-activated carbons (ACs) to capture CO[sub.2]. The pore structures, functional groups and morphology, and desorption performance of the prepared ACs were characterized; the CO[sub.2] adsorption, regeneration, and kinetics were also evaluated. The results showed that H[sub.3]PO[sub.4] and urea obviously promoted the development of pore structures and pyrrole nitrogen (N–5), while KOH and urea were more conductive to the formation of hydroxyl (–OH) and ether (C–O) functional groups. At optimal operating conditions, the CO[sub.2] adsorption capacity of H[sub.3]PO[sub.4]– and KOH–activated poplar leaves after urea treatment reached 4.07 and 3.85 mmol/g, respectively, at room temperature; both showed stable regenerative behaviour after ten adsorption–desorption cycles.