1988 Volume 14 Issue 1 Pages 79-86
Structural molecular sieving carbons (MSC) were produced from two kinds of polyvinylformal (PVF) forms with different chemical compositions under various production conditions, and the separation characteristics of air at low temperatures (140 to 300 K) were experimentally investigated in relation to the physical properties of the structural MSC produced. Based on the breakthrough measured in a packed bed of the structural MSC, the characteristics of N2-O2 separation from air were studied from the standpoints of the separation temperature, the chemical composition of a raw PVF form and the production conditions, and the reduction in separation ability by repetition of the operation was also examined. It seemed that the structural MSC produced in this work are usable for air separation at a low temperature. The results of the adsorption equilibrium and the rate for both N2 and O2 on the fine particle of the structural MSC showed that the separation of air at a low temperature is affected by the intraparticle diffusion rate rather than the adsorption amount of each component. These points suggested that the driving force of the separation at low temperature is the diffusion rate difference between N2 and O2, similarly to the case of a pressure swing adsorption.
