Gas Adsorption Performance Of Porous Carbon Materials

Small molecule gases (CO2, CH4, O2,N2and H2) adsorption properties in AC,ACF and carbon membrane were studied. Langmuir, Freundlich,DR Sips and Toth equations were used to fit experimental data and to calculate the pore structure parameters. Results show that AC and ACF display is a great difference in the gas adsorption capacity. The adsorption quantity order is CO>2>CH4>N2. The adsorption capacity of H2in ACF is the weakest, and the adsorption capacity of O2is close to N2, but less than the CH4’s. Carbon membrane display is a great difference in the gas adsorption capacity. The adsorption quantity order is CO2>O2>N2which is related to microporous volume of the adsorbents. The number of micropores increases initially and then decrease with increasing carbonization temperature. In addition, the adsorption capacity of ACF was signficantly higher than that of AC. And the adsorption capacity of O2in carbon membrane change slightly smaller than the CO2and N2when the carbonization temperature is increasing. The high CO2adsorption capacities make the AC and ACF potential candidates for N2and CO2separation. Different fitting methods have different characteristics:the DR equations are more suitable for the adsorption of different gases than tha Langmuir and Freundlich equations, but inferior to Sips and Toth equations. The Langmuir equation fits better for the adsorption of N2in AC and ACF.And the Freundlich equation fits better for the adsorption of O2in carbon membranes. Using three equations to fit is better at the carbonization temperature of750℃. It is best to use Toth equation to fit the active carbon adsorption-gas system and Sips equation to fit the adsorption of activated carbon fiber and carbon membrane gas system.Compared with the gas adsorption of porous carbon materials,it is find that the CO2adsorption ability of carbon membrane is stronger than that of activated carbon fiber and strong onactivated carbon. The N2adsorption ability of it is weaker that of activated carbon and onactivated carbon fiber.