## 1 Introduction  
Global warming is gaining wider recognition in the world. Fossil fuel power plants are responsible for approximately one-third of global CO\({}_{2}\) emissions to the atmosphere. Therefore, removing CO\({}_{2}\) from low-pressure flue gas (i.e., CO\({}_{2}\) capture in postcombustion) has been the focus of extensive research over the last few decades. As an alternative to the energy-intensive amine-based chemical absorption processes, CO\({}_{2}\) capture via adsorption on renewable biomass-derived carbons has gained increased interest, since these adsorbents are relatively cheap, require low energy for regeneration, and show a relatively good tolerance to moisture existing in flue gas [1]. An increasing number of studies have focused on producing activated carbons (ACs) from different biomass precursors (through physical or chemical activation) and assessing their performance in terms of CO\({}_{2}\) uptake at 10-15 kPa and selectivity towards CO\({}_{2}\) over N\({}_{2}\)[2; 3; 4; 5; 6; 7; 8; 9; 10]. At equilibrium conditions (i.e., adsorption isotherms of pure components), the biomass-derivedACs exhibit a relatively high CO\({}_{2}\) adsorption capacity, usually in the range of 1.0-2.0 mmol g\({}^{-1}\) at 15 kPa and 25 \({}^{\circ}\)C [9]. Regarding the apparent CO\({}_{2}\)/N\({}_{2}\) selectivity, which is defined as the ratio of molar uptakes divided by the ratio of partial pressures, values in the range of 8-14 (deduced from single component adsorption data at 25-50 \({}^{\circ}\)C) have been reported in previous studies [6; 11; 12]. It is generally accepted that the narrower micropores of ACs are the main responsible for the physical adsorption of CO\({}_{2}\) at low pressure. Therefore, and for a given AC, the CO\({}_{2}\) uptake at 10-15 kPa is primarily a function of its ultra-micropore volume (pore width below 0.7 nm). From a more realistic point of view, studies focusing on the behavior of biomass-derived ACs under dynamic conditions are explicitly required, since cyclic breakthrough measurements are more representative of practical separations. Adsorbents have to exhibit relatively fast adsorption and desorption kinetics for their successful implementation in swing adsorption processes. In this sense, the number of studies available is relatively modest compared to the large amount of research already conducted on developing ACs from biomass precursors. In a very interesting study [13], the performance under dynamic conditions of olive stone and almond shells-derived ACs (produced by single-step activation with CO\({}_{2}\) at 800 \({}^{\circ}\)C) was tested. For a feed stream composed of a binary mixture of CO\({}_{2}\)/N\({}_{2}\) (14/86 vol. %) at 50 \({}^{\circ}\)C and 120 kPa, the authors reported good CO\({}_{2}\) adsorption capacities (around 0.6 mmol g\({}^{-1}\)) and apparent selectivities CO\({}_{2}\)/N\({}_{2}\) (20-30) for fresh adsorbent. The fact that the selectivity increased for dynamic measurements was mainly explained by a certain decrease in the adsorbed amount of the weaker adsorbate (N\({}_{2}\)) in the presence of the stronger one (CO\({}_{2}\)). In other words, the apparent CO\({}_{2}\)/N\({}_{2}\) selectivity estimated from the single-component adsorption isotherms could be lower than that measured under dynamic conditions for binary mixtures. [PERSON] et al., [14] assessed the performance of several agricultural waste-based carbons, which were produced through slow or fast pyrolysis and then activated with KOH. The best results were obtained for a pinewood sawdust-derived AC, which exhibited high CO\({}_{2}\) uptake (1.8 mmol g\({}^{-1}\) after nine cycles) and apparent selectivity CO\({}_{2}\)/N\({}_{2}\) (29) at 25 \({}^{\circ}\)C and 101.3 kPa (for a binary mixture CO\({}_{2}\)/N\({}_{2}\) 15/85 vol. %). However, the temperature tested by [PERSON] et al., [14] was not within the typical range for postcombustion flue gas (40-60 \({}^{\circ}\)C). Moreover, the gas residence time selected by the authors (31 s) was relatively long.