Evaporative emissions, a major cause of air pollution, are primarily produced by automobiles and can be recovered using adsorbents. This study investigated the effect of the textural properties of polyimide (PI)-based activated carbon fibers (PIACFs) on the adsorption and desorption performance of n-butane, which are a type of evaporative emissions. PI-ACFs were prepared by varying the activation time while maintaining the identical crosslinking and carbonization conditions. The surface morphology and microstructural properties of the ACFs were examined using a field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD), respectively. The textural properties of ACF (specific surface area, pore volume, and pore size distribution) were analyzed using N2/ 77 K adsorption and desorption isotherm curves. The n-butane adsorption and desorption performance were evaluated according to modified ASTM D5228. From the results, the specific surface area and total pore volume of ACFs were determined to be 680–1480 m2/ g and 0.28–1.37 cm3/ g, respectively. Butane activity (BA) of the ACFs increased from 14.1% to 37.1% as the activation time increased, and especially it was found to have highly correlated with pore volume in the 1.5–4.0 nm range.

In this study, activated carbon with well-developed mesopores was fabricated using kenaf short fibers as a representative biomass. Concentrated phosphoric acid was selected as an activation agent to create highly developed porous structures, and pore development was observed to occur in relation to the weight ratio of phosphoric acid and kenaf. The pore characteristics of the kenaf-based activated carbon were determined using the N2/ 77K adsorption isotherm, and its microcrystalline structure was analyzed using X-ray diffraction. The highest specific surface area (1570 m2/g) was observed when the weight ratio of phosphoric acid to kenaf was 3:1, and the highest mesopore fraction (74%) was observed at 4:1. The carbonization yield was 45–35%, which is higher than that of commercial activated carbon. The production of porous carbon material by this method offers high potential for application because it can be controlled over a wide range of average pore diameter from 2.48 to 5.44 nm.

Mesoporous activated carbon (AC) was prepared from aged petroleum coke through chemical activation. The AC has a specific surface area of 1733 m2/g and a mean pore diameter of 2.37 nm. The volume fraction of 2 to 4nm pores is 56.74%. At a current density of 10 mA/cm2, a specific capacitance of 240 F/g is achieved representing the use factor of the surface area of 69.2%. And the electrical double layer capacitor (EDLC) based on the AC shows an excellent power performance. This result suggests that the presence of high fraction of mesopores can effectively increase the adsorption efficiency of the specific surface area of the AC and enhance the power performance of EDLC based on the efficient surface area of the AC.