Toluene adsorption on various activated carbons with different pore structures

The toluene adsorption behavior of various activated carbons with different surface areas and pore structures was investigated by a static method at saturation concentration and a dynamic method at low concentration. The pore structures of these activated carbons were characterized by nitrogen adsorption at 77 K and ¹²⁹Xe-NMR measurements. Results showed that activated carbons with a larger pore volume have the higher toluene adsorption capacity at saturation concentration. But at low concentration, activated carbons with abundant micropores and a narrow pore size have a higher adsorption capacity. Among the investigated samples, pitch-based activated carbon fibers (ACFs) showed a better toluene adsorption capacity at low concentration (2 × 10^-5). With the increase of surface area for ACFs, the toluene ad sorption capacities at low concentration (2 × 10^-5) increase slightly and for OG5A, OG10A, OG15A and OG20A at 30°C were 202 mg/g, 219 mg/g, 221 mg/g and 235 mg/g respectively.