Porous carbons for CO2 capture at low pressures were prepared by KOH activation of rice husk char. Low activation temperature (640-710 degrees C) and small KOH/char ratio (1:1) favored the increase in low-pressure CO2 uptake. The CO2 uptakes at 0.1 bar (0 degrees C) reached 2.11 mmol/g, which were probably the highest value ever reported for porous carbons prepared from lignocellulosic biomass. The high CO2 uptakes at low pressures were ascribable to the presence of micropores (<0.7 nm or <1 nm), the narrow micropore size distribution, or the existence of nitrogen. The obtained porous carbons also exhibited a large CO2 uptake at 1 bar (6.24 mmol/g at 0 degrees C) and good CO2-over-N-2 selectivity. No noticeable change in CO2 uptake was observed after five successive runs of adsorption-desorption. The excellent recyclability, high CO2 uptakes, and good selectivity show that high-performance porous carbons for capturing CO2 at low pressures can be prepared by KOH activation of rice husk char. (C) 2014 Elsevier Ltd. All rights reserved.