CO2/N-2 Separation on Highly Selective Carbon Nanofibers Investigated by Dynamic Gas Adsorption

The development of highly selective adsorbents for CO2 is a key part to advance separation by adsorption as a viable technique for CO2 capture. In this work, polyacrylonitrile (PAN) based carbon nanofibers (CNFs) were investigated for their CO2 separation capabilities using dynamic gas adsorption. The CNFs were prepared by electrospinning and subsequent carbonization at various temperatures ranging from 600 to 1000 degrees C. A thorough investigation of the CO2/N-2 selectivity resulted in measured values of 53-106 at 1 bar and 25 degrees C on CNFs carbonized at 600, 700, or 800 degrees C. Moreover, the selectivity increased with lower measurement temperatures and lower CO2 partial pressures, reaching values up to 194. Further analysis revealed high long-term stability with no degradation over 300 cycles and fast adsorption kinetics for CNFs carbonized at 600 or 700 degrees C. These excellent properties make PAN-based CNFs carbonized at 600 or 700 degrees C promising candidates for the capture of CO2.