Simultaneous production of N-15, O-18, O-17 isotopes in cascades with discrete homogeneous isotope exchange

The possibility of simultaneously obtaining N-15, O-18 and O-17 isotopes in ordinary and double cryogenic distillation cascades with discrete homogeneous isotope exchangers was analysed. A physical model is presented of multi-component mixture separation in a cascade in the presence of homogeneous isotopic exchange. Investigation of the regularities of target isotope transfer showed that the optimum choice of the location of an exchanger can increase target isotope transfer by a factor of 2.5 - 5.0 compared to transfer in a cascade without exchangers. Optimum column length, circulation flow, number and locations of exchangers were determined for ordinary and double cascades. An ordinary cascade can be used to enrich N-15 and O-18 up to 90%, and a double cascade can be used to enrich O-17 up to 60% and N-15 and O-18 up to 90%.