The gravimetric adsorption capacity of the electrodes increased significantly from 70 mmol.kg -1 for BPL-AC electrodes to 273 mmol.Kg -1 for GR-AC electrodes and followed the sequence GR-AC > GP-AC > GS-AC > S-AC > Y-AC > BPL-AC (blue dots in Figure ). The trend of increase in adsorption capacity is consistent with increasing specific capacitance of the electrodes, except for GS-AC and S-AC, which show the third and fourth highest sorption capacity but flip positions for the trend in specific capacitance. The higher adsorption capacity of GS-AC (247 mmol.Kg -1 ) as compared to S-AC (201 mmol.Kg -1 ) can be attributed to its higher mesoporous surface area compared to S-AC, which ease the transport of ions and electrons for more effective utilization of surface area. GP-AC shows the second highest adsorption capacity (255 mmol.Kg -1 ) while Y-AC shows the second lowest sorption capacity (84.5 mmol.Kg -1 ), consistent with the specific capacitance trends. The volumetric performance metrics of the electrodes are also practically relevant because they influence land use, the capital cost for housing the modules, and the ratio between non-adsorbing components (current collector, separator, gas diffusion layer), and the adsorbing electrodes. The volumetric capacitance (CV) of the electrodes follows the sequence: S-AC > Y-AC > GP-AC > GS-AC > GR-AC > BPL-AC (Figure and Table ). However, the volumetric adsorption capacities follow the sequence: GP-AC > GS-AC > S-AC > GR-AC > Y-AC > BPL-AC. Capacitance and adsorption capacity are not as strongly correlated on a volumetric basis, unlike gravimetric capacitance/sorption capacity. GP-AC, GS-AC, and S-AC show the volumetric adsorption capacities of 65.3 mol.m -3 , 52.9 mol.m -3 , and 47.3 mol.m -3 and exhibit volumetric capacitances of 62.3 F.m -3 , 49.0 F.cm -3 , and 71.3 F.cm -3 , respectively. The biggest discrepancy between capacitive and adsorptive performance exists for Y-AC which ranks second for capacitive, but fifth for adsorptive performance. The results indicate that volumetric adsorption capacity does not solely depend on the volumetric capacitance but also on factors such as the carbon source, surface functionalities, and pore size distribution. Nonetheless, the approximately four-fold improvement in gravimetric adsorption capacity (GR-AC) and two-fold improvement in volumetric adsorption capacity (GP-AC) as compared to BPL carbon electrodes show that biomass derived carbons can be an inexpensive and efficient source for capturing CO2 using SSA, and there might be room for further improvement. Differences between gravimetric and volumetric adsorption performances can be explained by the different densities of the materials. GR-AC has the lowest density, and therefore this material is able to use the carbon mass most effectively. This does not translate to the highest volumetric capacity because the low density creates "wasted" pore space that cannot be used for adsorption. GP-AC has a higher density and is not as effective on a mass basis because less many carbon atoms are accessible for adsorption. On the other hand, the higher density leads to less "wasted" pore space, which explains the high volumetric performance.