Enhanced CO₂ Capture Capacity of Nitrogen-Doped Biomass-Derived Porous Carbons

Abstract

Nitrogen-doped porous carbons obtained from coconut shell by urea modification and KOH activation are found to exhibit very high CO2 uptake at 1 bar, almost 5 mmol g–1 at 25 °C and over 7 mmol g–1 at 0 °C, respectively. The high CO2 uptake of the sorbent can be ascribed to its high microporosity and nitrogen content. In addition, these sorbents possess high CO2/N2 selectivity, stable cyclic ability, high initial heat of CO2 adsorption, fast adsorption kinetics, and high dynamic CO2 capture capacity under simulated flue gas conditions. When combined with the low cost of the coconut-shell precursor, these properties make them exceptionally attractive sorbent candidates for CO2 capture.