Structural, kinetic and performance characterization of hollow fiber carbon membranes

The hollow fiber carbon membranes (HFCMs) were prepared from different deacetylated cellulose acetate precursors by controlled carbonization procedure with CO2 purge gas, a heating rate of 4 K/min, a final temperature of 550 degrees C and a final soak time 2 h. The SEM images and TGA analysis indicated that the carbon membranes form a symmetric structure and a high average weight loss during the carbonization process. The Langmuir affinity parameters of the carbon membranes were estimated by the CO2 and N-2 adsorption equilibrium data. The membrane structure parameters of micropore volume, average pore size and d-spacing were determined by the CO2 adsorption experiments combined with XRD characterization. The kinetic rate constants were also obtained from the CO2 kinetic adsorption experiments. Single gas permeation tests of H-2, CO2, O-2, N-2 and CH4 were conducted to investigate the transport mechanism in the carbon membrane separation process. Moreover, the influences of temperature and feed pressure on the gas separation performances were also studied on the basis of the single gas and gas mixture (synthetic flue gas, CO2-N-2-O-2) measurements. (C) 2011 Elsevier B. V. All rights reserved.