~(13)CO AND ~(12)CO SEPARATION ON Na-LSX USING PRESSURE-SWING ADSORPTION AT LOW TEMPERATURES

摘要

Abstract. Economical ~(13)CO separation is a very important process, not only for the production of isotopic labels for nuclear magnetic resonance chemical analysis and medical diagnosis, but also to provide a means of removing and fixing radioactive carbon (carbon-14) in the nuclear power industry.~(13)C is normally separated from ~(13)C/~(12)C CO or from ~(13)C/~(12)C CH_4 by cryogenic processes. As the separation factor is small, the cost of separation is very high, so that the application of ~(13)C is limited to use in the laboratory as a chemical reagent. It is not viable to use it for industrial purposes. A marked difference was observed between the adsorption equilibrium coefficients of ~(13)CO and ~(12)CO on a low-SiO_2/Al_2O_3-ratio Na-X type zeolite (Na-LSX) at low temperatures, so this phenomenon could be used to separate ~(13)CO from ~(12)CO.